CN107870397B - Wavelength Selective Optical Switch - Google Patents

Abstract

A wavelength selective optical switch is proposed, which includes a polarization beam splitting unit and a wavelength selection unit. The wavelength selection unit includes: a polarization beam splitting unit, which is used to split an input beam into a first polarized beam and a second polarized beam, and split the first polarized beam into a second polarized beam. The polarized beam is transmitted to the input end of the first group of micro-ring resonators, and the second polarized beam is transmitted to the input end of the second group of micro-ring resonators; the first group of micro-ring resonators is used to transmit the The first target beam is coupled to the first group of micro-ring resonators, and the first target beam is output to the polarization beam combining unit; the second group of micro-ring resonators is used to couple the second target beam in the second polarized beam into the second group of microring resonators, and output the second target beam to the polarization beam combining unit; the polarization beam combining unit is used to combine the first target beam and the second target beam. In this way, the number of times of polarization state conversion of the first polarized light beam and the second polarized light beam is the same, which can reduce the polarization-dependent loss.

Description

Wavelength Selective Optical Switch

technical field

The present invention relates to the field of communications, in particular to a wavelength selective optical switch in the field of communications.

Background technique

With the application of dense wavelength division multiplexing (Dense Wavelength Division Multiplexing, "DWDM" for short) technology in optical fiber communication systems and data center systems, all-optical switching has become a trend to meet the increasing bandwidth. In the dense wavelength division multiplexing system, each different optical wavelength carries a different optical signal, and the optical signals of different wavelengths are transmitted in the same optical fiber, realizing high-capacity and low-loss data communication. Optical switch is the key device to realize all-optical switching system. It can realize all-optical layer routing selection, wavelength selection, optical cross-connection, self-healing protection and other functions. The optical switches that have been realized so far include traditional mechanical structure optical switches, switches based on micro-optical electromechanical systems, liquid crystal optical switches, waveguide type optical switches and semiconductor optical amplifier optical switches. Among them, the waveguide type optical switch usually relies on the mature complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, referred to as "CMOS") process on the silicon (Silicon-On-Insulator, referred to as "SOI") platform or indium phosphide on the insulating substrate. (Indium Phosphide, referred to as "InP") platform, using the thermo-optic effect or plasmonic dispersion effect of silicon material can make the switching speed reach nanosecond to microsecond level, and the volume is small, the integration is high, and it is compatible with the CMOS process. Compatible, thus enabling low-cost mass production. The waveguide-type microring resonator is a wavelength-sensitive selective conduction device. It has the advantages of compact structure, high integration, low power consumption, and simple design. It can be used to realize filtering, multiplexing, and demultiplexing. , routing, wavelength conversion, optical modulation, optical switching and other functions. When the wavelength-division multiplexed optical signal passes through the micro-ring resonator, if the wavelength of the optical signal matches the resonant wavelength of the micro-ring resonator, the optical signal will be coupled to the micro-ring resonator to resonate, thereby realizing the specified wavelength. Routing functions for optical signals. Compared with the cascaded Mach-Zehnder-interferomete (MZI) type silicon-based optical switch matrix, the optical switch array composed of micro-ring resonators has a simpler topology, fewer stages, and has the advantages of Wavelength selectivity, so the optical signal of the pass-through wavelength will not be affected by the coupling of the micro-ring resonator, and the insertion loss of the pass-through is very low. Especially in the metropolitan area aggregation ring of the metropolitan area optical network, the optical switch of the microring resonator type has the functions of filtering and uploading and downloading signals at the same time, which makes the switching node equipment simple and efficient.

However, the existing microring resonators usually only support the upload and download of signal light in a single polarization state, because the resonance wavelength of the microring resonator is very sensitive to the effective refractive index and structure size of the waveguide. Generally speaking, the effective refractive index of the TE mode and the TM mode of the waveguide are different, resulting in different resonant wavelengths of the TE mode and the TM mode, so the microring resonator cannot handle the polarization-multiplexed optical signal. Even if some specially designed waveguide structures with square or ridge cross-sections are used to make the effective refractive index or group refractive index of the TE mode and the TM mode of the waveguide equal, the change of the wavelength structure size caused by the process error will lead to the TE mode and the TM mode. The resonant wavelengths of the TM modes are not the same. This will limit the application scenarios of microring resonators in metro optical networks. How to design a micro-ring resonator optical switch with low polarization-dependent loss is one of the key technologies for convergence ring optical switching nodes in metropolitan area optical networks.

SUMMARY OF THE INVENTION

In view of this, the embodiments of the present invention provide a wavelength selective optical switch, which can reduce polarization-dependent loss in the selection process of polarization-independent optical signals.

In a first aspect, an embodiment of the present invention provides a wavelength selective optical switch, including a polarization beam splitting unit and a wavelength selection unit, and the wavelength selection unit includes two groups of microring resonators and a polarization beam combining unit,

The polarization beam splitting unit is used to split the input beam into a first polarized beam and a second polarized beam, and transmit the first polarized beam to the first group of microring resonators in the two groups of microring resonators The input end of the second polarized light beam is transmitted to the input end of the second group of micro-ring resonators in the two groups of micro-ring resonators;

the first group of microring resonators for coupling a first target beam of the first polarized light beams transmitted to the input of the first group of microring resonators to the first group of microring resonators and output the first target beam coupled to the first group of microring resonators to the polarization beam combining unit from the output end of the first group of microring resonators. The wavelength of a target light beam is equal to the target wavelength corresponding to the wavelength selection unit;

the second group of microring resonators for coupling the second target beam in the second polarized light beam transmitted to the input end of the second group of microring resonators to the second group of microring resonators and output the second target beam coupled to the second group of micro-ring resonators to the polarization beam combining unit from the output end of the second group of micro-ring resonators. The wavelength of the two target beams is equal to the target wavelength;

The polarization beam combining unit is used for combining the first target beams received from the output ends of the first group of microring resonators and the light beams received from the output ends of the second group of microring resonators The second target beam is combined, and a combined beam of the first target beam and the second target beam is output.

Therefore, the wavelength selective optical switch performs the same wavelength selection process on the two polarized beams, so that the number of polarization state conversions of the first polarized beam and the second polarized beam is the same, so the polarization-dependent loss can be reduced, which is beneficial to the optical switching node performance.

Moreover, in the wavelength selective optical switch, the transmission paths of the first polarized beam and the second polarized beam in the optical waveguide are equal or similar, which can further reduce the polarization-dependent loss and also reduce the differential group velocity delay.

Optionally, in an implementation manner of the first aspect, the polarization beam splitting unit splits the polarization beam splitting unit with a first optical waveguide connecting the input end of the first group of microring resonators A first polarized light beam is transmitted to the input of the first set of microring resonators, and light beams of the first polarized light beam not coupled to the first set of microring resonators are along the first optical waveguide continue to transmit;

The polarization beam splitting unit transmits the second polarized beam to the second group of microring resonators through a second optical waveguide connecting the polarization beam splitting unit and the input end of the second group of microring resonators The input end of the second polarized light beam, and the light beam in the second polarized light beam that is not coupled to the light beam in the second group of microring resonators continues to transmit along the second optical waveguide.

It should be understood that the wavelength selective optical switch can be used for the selection of polarized light with any polarization state, that is, the first polarized light beam and the second polarized light beam can be polarized light beams with any polarization mode, in particular, the first polarized light beam and the second polarized light beam can be polarized light beams with any polarization mode. The polarized light beam may be an optical signal in a TE mode or a TM mode, and the second polarized light beam may be an optical signal in a TE mode or a TM mode.

Optionally, in an implementation manner of the first aspect, the first polarized light beam and the second polarized light beam are polarized light beams of the same mode, wherein the microrings in the first group of microring resonators are The resonators and the microring resonators in the second group of microring resonators are microring resonators matching the same mode.

For example, if the first polarized beam is a TM mode polarized beam, then the microring resonators in the first group of microring resonators can be designed to match the TM mode; if the second polarized beam is a TE mode , then the microring resonators in the second group of microring resonators can be designed as microring resonators matching the TE mode.

Optionally, in an implementation manner of the first aspect, the polarization beam splitting unit includes a polarization beam splitter rotator, and the polarization beam combining unit includes a polarization beam combiner rotator.

Therefore, the number of polarization state transitions of the first polarized beam and the second polarized beam is the same, and the distances transmitted by the first polarized beam and the second polarized beam in the optical waveguide are equal, which can reduce polarization-dependent loss and differential group velocity time delay.

Moreover, since the microring resonators in the first group of microring resonators and the microring resonators in the second group of microring resonators are microring resonators for the same polarization mode, the same polarization state can be processed using The same micro-ring resonator of the light beam does not need to design two sets of different micro-ring resonators, which reduces the complexity of the system and reduces the complexity of control.

It should be understood that the polarization beam splitting unit in this embodiment may also include other devices capable of splitting and rotating the input optical signal, so as to realize dividing the input optical signal into two polarized beams such as the TE mode optical signal and the TM mode optical signal signal, and convert one of the polarized light beams, such as TM mode optical signal, into TE mode optical signal. For example, the polarization beam splitting unit may include a polarization beam splitter and a polarization converter, or other optical structures capable of realizing this function. Likewise, the polarization beam combining unit may also include other devices capable of combining and rotating the input optical signal.

Optionally, in an implementation manner of the first aspect, the first polarized light beam and the second polarized light beam are polarized light beams of different modes, wherein the microrings in the first group of microring resonators are The resonator is a microring resonator that matches the mode of the first polarized beam, and the microring resonator in the second group of microring resonators is a microring that matches the mode of the second polarized beam resonator.

Optionally, in an implementation manner of the first aspect, the polarization beam splitting unit includes a polarization beam splitter, and the polarization beam combining unit includes a third optical waveguide, and the third optical waveguide is used to The first target beam and the second target beam are coupled.

That is to say, the combining of the first target light beam and the second target light beam is completed in the coupling optical waveguide, and other combining devices need not be added.

Therefore, the polarization state conversion between the first polarized light beam and the second polarized light beam is not required, which greatly reduces the polarization-dependent loss. In addition, the difference between the transmission distances of the first polarized beam and the second polarized beam in the optical waveguide is significantly reduced, which can further reduce the polarization-dependent loss and also reduce the differential group velocity delay.

Optionally, in an implementation manner of the first aspect, the first group of micro-ring resonators includes one micro-ring resonator or a plurality of micro-ring resonators that are cascaded, and the second group of micro-ring resonators It consists of one microring resonator or multiple microring resonators in cascade.

Therefore, the wavelength selective optical switch can expand the working spectral bandwidth of the optical switch by using a plurality of micro-ring resonators in cascade.

Further, the number of microring resonators in the first group of microring resonators is equal to the number of microring resonators in the second group of microring resonators. Therefore, the structural complexity of the wavelength selection unit is reduced, the path difference between the two polarized light beams when transmitted in the optical waveguide is reduced, and the polarization-related loss is reduced.

Optionally, in an implementation manner of the first aspect, the wavelength selective optical switch further includes a wavelength detection unit corresponding to the wavelength selection unit, and the wavelength detection unit is used for detecting the first target beam. The wavelength and the wavelength of the second target beam are detected.

Optionally, in an implementation manner of the first aspect, the wavelength detection unit includes a first optical coupler located at the output end of the first group of microring resonators, and is coupled to the first optical coupler. A first photodetector connected to the second set of microring resonators, a second photocoupler located at the output end of the second group of microring resonators, and a second photodetector connected to the second photocoupler.

In the wavelength selection unit, an optical coupler can be set at each of the output ends of the two groups of microring resonators to extract a small amount of optical signal energy from the trunk and send it to the optical detector for monitoring. The photodetector feeds back the extracted part of the optical signal to the electrodes of the two groups of microring resonators through an external feedback circuit respectively, and stably downloads by compensating in real time the change in the resonance wavelength of the two groups of microring resonators. The wavelength of the optical signal.

Therefore, by setting a wavelength monitoring unit in the wavelength selective optical switch to monitor and compensate the target wavelength in real time, the wavelength of the optical signal downloaded by the wavelength selective unit can be stabilized.

In a second aspect, a wavelength selective optical switch is provided, which is characterized by comprising the polarization beam splitting unit described in the first aspect and various implementations, and at least one of the polarization beam splitting units described in the first aspect and various implementations The wavelength selection unit, wherein the target wavelength corresponding to each wavelength selection unit in the at least one wavelength selection unit is different

For example, the wavelength selective optical switch may include the above-mentioned polarization beam splitting unit, and n above-mentioned wavelength selection units, wherein the light beam that does not meet the target wavelength in the first polarized light beam output by the i-th wavelength selection unit is different from the light beam of the first polarized light beam output by the i-th wavelength selection unit. The light beams that do not meet the target wavelength among the two polarized light beams respectively enter the i+1th wavelength selection unit. The light beam that does not meet the target wavelength in the first polarized light beam passes through the first group of microring resonators in the i+1 wavelength selection unit to realize the selection of the light beam that meets the target wavelength λ _i+1 , and the second polarized light beam does not meet the target wavelength. The light beam meeting the target wavelength passes through the second group of microring resonators in the i+1 th wavelength selection unit, so as to realize the selection of the light beam meeting the target wavelength λ _i+1 .

Based on the wavelength selective optical switch according to the embodiment of the present invention, two groups of micro-ring resonators are arranged to perform the same wavelength selection processing on the two polarized light beams, so that the number of polarization state conversions of the first polarized light beam and the second polarized light beam is the same, Thus, the polarization-dependent loss is reduced, which is beneficial to the performance of the optical switching node.

Moreover, the transmission paths of the two polarized beams in the optical waveguide are equal or similar, which can further reduce the polarization-dependent loss and also reduce the differential group velocity delay.

In addition, the wavelength selective optical switch in the embodiment of the present invention is simple in structure and compact in volume, and can also form a large-scale optical switch matrix.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings that need to be used in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of a polarization-independent microring resonator in the prior art.

FIG. 2 is a schematic structural diagram of a wavelength selective optical switch according to an embodiment of the present invention.

FIG. 3 is a schematic structural diagram of a wavelength selective optical switch according to another embodiment of the present invention.

FIG. 4 is a schematic structural diagram of a wavelength selective optical switch according to another embodiment of the present invention.

FIG. 5 is a schematic structural diagram of a wavelength selective optical switch according to another embodiment of the present invention.

FIG. 6 is a schematic structural diagram of a wavelength selective optical switch according to another embodiment of the present invention.

FIG. 7 is a schematic structural diagram of a wavelength selective optical switch according to another embodiment of the present invention.

FIG. 8 is a schematic structural diagram of a wavelength selective optical switch according to another embodiment of the present invention.

FIG. 9 is a schematic structural diagram of a wavelength selective optical switch according to another embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

FIG. 1 is a schematic structural diagram of a polarization-independent microring resonator in the prior art. The microring resonator 100 includes two parts: a polarization-sensitive working unit 110 and a polarization-rotating mirror 120 . The polarization-multiplexed optical signal includes the TE mode optical signal and the TM mode optical signal. The input polarization-multiplexed optical signal enters the polarization-independent micro-ring resonator structure from the bus optical waveguide 130, and passes through the polarization beam splitter 111. The signal is output from the optical waveguide 112 , and the TM mode optical signal is output from the optical waveguide 113 . Among them, the optical waveguide 112 is coupled with the micro-ring resonator 114, and the TE mode optical signal conforming to the resonant wavelength of the micro-ring resonator 114 is coupled into the micro-ring resonator 114 and transmitted in the counterclockwise direction, and is coupled out from the output optical waveguide 115 and enters the polarization Multiplexer 118 . The TM mode optical signal in the optical waveguide 113 is transmitted to the far-end polarization rotating mirror 121, and is reflected back into the TE mode optical signal TE _TM , which enters the optical waveguide 112, and is transmitted in the opposite direction to the TE optical signal. The polarization rotating mirror 120 includes a polarization rotator 121 and a curved waveguide 122 . The optical signal TE _TM conforming to the resonant wavelength of the micro-ring resonator 114 is coupled into the micro-ring resonator 114 and transmitted in a clockwise direction, coupled out from the output optical waveguide 115, and then converted into the TM mode through the curved optical waveguide 116 and the polarization rotator 117 The optical signal enters the polarization combiner 118 . The polarization combiner 118 multiplexes the input TE mode optical signal and the TM mode optical signal and outputs it from the bus optical waveguide 140, thereby realizing a polarization-independent filtering and switching function.

However, in this microring resonator, the optical waveguide lengths through which the TE mode optical signal and the TM mode optical signal pass are very different, and the TM mode optical signal undergoes a large number of polarization state transitions, which will cause serious polarization-dependent loss and The differential group velocity delay affects the system performance; moreover, the micro-ring resonator has a complex structure and a large volume, so it is not suitable for forming a large-scale optical switch matrix.

The polarization-dependent loss here refers to the difference in energy loss generated after optical signals of different polarization states pass through a system. difference in loss. The smaller the difference, the less sensitive the optical switch is to the polarization state.

Wavelength Selective Switch (WSS) is a subsystem of the wavelength division system that has developed rapidly in recent years. It can switch optical signals of different wavelengths between any input and output ports. The networking capability of the wavelength division system is greatly improved. In terms of working principle, wavelength selective switches can be divided into micro-electromechanical type, planar waveguide type and liquid crystal type and so on. The wavelength selective optical switch in the embodiment of the present invention is one of the planar waveguide type.

FIG. 2 is a schematic structural diagram of a wavelength selective optical switch according to an embodiment of the present invention. The wavelength selective optical switch includes a polarization beam splitting unit 310 and a wavelength selection unit 320, wherein the wavelength selection unit 320 includes two groups of micro-ring resonators and a polarization beam combining unit 323, and the two groups of micro-ring resonators include a first group of micro-ring resonators. Ring resonator 321 and a second set of microring resonators 322 .

The polarization beam splitting unit 310 is used to split the input beam into a first polarized beam and a second polarized beam, and transmit the first polarized beam to the input end of the first group of microring resonators 321 in the two groups of microring resonators, transmitting the second polarized light beam to the input end of the second group of microring resonators 322 in the two groups of microring resonators;

The first group of micro-ring resonators 321 is used to couple the first target beam in the first polarized light beam transmitted to the input end of the first group of micro-ring resonators 321 into the first group of micro-ring resonators 321, and couple The first target beam coupled to the first group of microring resonators 321 is output from the output end of the first group of microring resonators 321 to the polarization beam combining unit 323 , and the wavelength of the first target beam is equal to the wavelength corresponding to the wavelength selection unit 320 target wavelength;

The second group of microring resonators 322 is used for coupling the second target beam in the second polarized light beam transmitted to the input end of the second group of microring resonators 322 into the second group of microring resonators 322 and coupling The second target beam coupled to the second group of microring resonators 322 is output to the polarization beam combining unit 323 from the output end of the second group of microring resonators 322, and the wavelength of the second target beam is equal to the target wavelength;

The polarization beam combining unit 323 is configured to perform the first target beam received from the output end of the first group of micro-ring resonators 321 and the second target beam received from the output end of the second group of micro-ring resonators 322 . beams are combined, and a beam obtained by combining the first target beam and the second target beam is output.

Specifically, the polarization-multiplexed and wavelength-multiplexed input light beam is divided into two polarized light beams with different polarization states through the polarization beam splitting unit, namely, a first polarized light beam and a second polarized light beam. The two polarized beams enter the wavelength selection unit 320 through the input component. As shown in FIG. 2 , the first polarized beam enters the first group of microring resonators 321 in the wavelength selection unit 320, and the second polarized beam enters the second group of microrings In the resonator 322, in the embodiment of the present invention, the direction of the arrow in the drawing is a schematic representation of the propagation direction of the light beam in the optical waveguide.

The first target beam in the first polarized beam transmitted to the input end of the first group of micro-ring resonators 321 is coupled to the first group of micro-ring resonators 321 to generate resonance, thereby realizing the selection of the optical signal of the specified wavelength λ _i , the first group of micro-ring resonators 321 couples the first target light beam satisfying the target wavelength λ _i in the first polarized light beam into the first group of micro-ring resonators 321 , where λ _i is the first group of micro-ring resonators 321 the resonant wavelength. The second polarized light beam entering the second group of micro-ring resonators 322 is coupled to the second group of micro-ring resonators 322 to generate resonance, thereby realizing the selection of the optical signal of the specified wavelength λ _i , the second micro-ring resonator group 322 The second target beam satisfying the target wavelength λ _i in the second polarized beam is coupled into the second group of micro-ring resonators 322 , wherein the resonant wavelength of the second group of micro-ring resonators 322 is also λ _i . The resonance wavelength of the first group of micro-ring resonators 321 is equal to the resonance wavelength of the second group of micro-ring resonators 322 , and both are equal to the target wavelength λ _i .

The first target beam coupled from the first polarized beam by the first group of micro-ring resonators 321 is transmitted to the polarized beam combining unit 323 through the optical waveguide between the first group of micro-ring resonators 321 and the polarizing beam combining unit 323 , The optical waveguide between the first group of micro-ring resonators 321 and the polarization beam combining unit 323 is coupled with the first group of micro-ring resonators 321, so that the output beams of the first group of micro-ring resonators 321 can enter The optical waveguide is thus transmitted to the polarization beam combining unit 323 .

Similarly, the first target beam coupled from the first polarized beam by the second group of microring resonators 322 is transmitted to the polarized beam combining through the optical waveguide between the second group of microring resonators 322 and the polarizing beam combining unit 323 323, the optical waveguide between the second group of micro-ring resonators 322 and the polarization beam combining unit 323 is coupled with the second group of micro-ring resonators 322, so that the output beam of the second group of micro-ring resonators 322 The optical waveguide can be entered to be transmitted to the polarization beam combining unit 323 .

The polarization beam combining unit 323 combines the first target beam coupled out of the first group of micro-ring resonators 321 and the second target beam coupled out of the second group of micro-ring resonators 322 and combines the first target beam with the second target beam The target beam is output after the combined beam, so as to complete a process of wavelength selection. The single-wavelength optical signal output by the wavelength selection unit 320 satisfies the target wavelength λ _i .

It can be seen that, in the wavelength selective optical switch of the embodiment of the present invention, the wavelength selection process is performed on the two polarized light beams at the same time, so that the number of polarization state conversions of the first polarized light beam and the second polarized light beam is the same, so it can be reduced The polarization-dependent loss is beneficial to the performance of the optical switching node.

In addition, the first group of micro-ring resonators and the second group of micro-ring resonators have the same processing process for the two polarized light beams, so that the transmission distances of the first polarized light beam and the second polarized light beam in the optical waveguide are equal or Similarly, the differential group velocity delay can be further reduced while the polarization-dependent loss is further reduced.

In addition, compared with the wavelength selective optical switch in the prior art, the wavelength selective optical switch in the embodiment of the present invention has a simple structure and a compact volume, and is suitable for forming a large-scale optical switch matrix.

As another embodiment, the polarization beam splitting unit 310 transmits the first polarized light beam to the first group of microring resonators 321 through the first optical waveguide connecting the polarization beam splitting unit 310 and the input end of the first group of microring resonators 321 the input end of , and the light beams in the first polarized light beams that are not coupled to the first group of microring resonators 321 continue to transmit along the first optical waveguide;

The polarization beam splitting unit 310 transmits the second polarized beam to the input end of the second group of microring resonators 322 through the second optical waveguide connecting the polarization beam splitting unit 321 and the input end of the second group of microring resonators 322, and the first The light beams of the two polarized light beams that are not coupled into the second set of microring resonators 322 continue to propagate along the second optical waveguide.

It should be understood that when the edge of the microring resonator and other devices (such as straight waveguides) are close to each other in space, until the distance between the two reaches the same order of magnitude as the wavelength (such as the order of micrometers) or smaller (such as the order of nanometers), The light fields in the two interact, which we call coupling.

When the input ends of the first group of microring resonators 321 and the first optical waveguide are close to each other in space, until the distance between the two reaches the same order of magnitude as the target wavelength or less, the optical fields in the two interact to realize the first The coupling between a group of micro-ring resonators 321 and the first optical waveguide; when the input end of the second group of micro-ring resonators 322 and the second optical waveguide are close to each other in space, until the distance between the two reaches the same target wavelength An order of magnitude or less, the optical fields in the two interact to realize the coupling between the second group of microring resonators 322 and the second optical waveguide.

Specifically, in the first polarized light beam transmitted to the input end of the first group of micro-ring resonators 321 , the first group of micro-ring resonators 321 couples the first target light beam satisfying the target wavelength λ _i to the first group of micro-ring resonators In the second polarized light beam transmitted to the input end of the second group of micro-ring resonators 322, the second micro-ring resonator group 322 couples the second target light beam satisfying the target wavelength λ _i to the second group of micro-ring resonators In the resonator 322, and the first target beam and the second target beam are combined in the polarization beam combining unit 323 and output, and are not coupled to the first group of microring resonators 321 that do not meet the target wavelength _λi . The remaining light beams continue to propagate in the first optical waveguide, and the remaining light beams that are not coupled to the second group of microring resonators 322 that do not meet the target wavelength λ _i continue to propagate in the second optical waveguide.

It should be understood that the light beam in the embodiment of the present invention may also be referred to as an optical signal. Each different optical wavelength carries a different optical signal, and the optical signals of different wavelengths are transmitted together in the optical waveguide, for example, transmitted in the same optical fiber. , which can realize large-capacity and low-loss data communication.

As another embodiment, the wavelength selective optical switch of the embodiment of the present invention includes a polarization beam splitting unit 310 and at least one wavelength selection unit 320, wherein the target wavelengths corresponding to each wavelength selection unit 320 are different.

It should be understood that the target wavelengths corresponding to each wavelength selection unit 320 in at least one wavelength selection unit in the wavelength selective optical switch are different, that is, the wavelengths of the optical signals output by each wavelength selection unit are different. For example, the wavelengths corresponding to the three wavelength selection units shown in FIG. 3 are λ _i , λ _i+1 and λ _n respectively. The above description takes one of the wavelength selection units 320 as an example, and the target wavelength corresponding to the wavelength selection unit 320 is λi.

It should also be understood that, in the embodiment of the present invention, the input beam is polarization multiplexed and wavelength-division multiplexed; the output beam finally output by the polarization beam combining unit 323 is the beam after combining the first target beam and the second target beam. , is a single-wavelength polarization-multiplexed beam that satisfies the target wavelength. After passing through the polarization beam splitting unit 310 and the wavelength selection unit 320, the original input beam is changed from a multi-wavelength beam to a single-wavelength output beam.

The wavelength selective optical switch according to the embodiment of the present invention will be described in detail below with reference to FIGS. 4 to 9 . As shown in FIGS. 3 to 9 , two wavelength selection units 320 are shown, namely the i-th wavelength selection unit 320 (corresponding to wavelength λ _i ) and the i+1-th wavelength selection unit 320 (corresponding to wavelength λ _i+1 ) , but the wavelength selective optical switch may also include more wavelength selection units 320, which may be selected according to actual application conditions. A detailed description will be given below with reference to the i-th wavelength selection unit shown in FIG. 3 to FIG. 9 . For other wavelength selection units, reference may be made to the relevant description of the wavelength selection unit.

Optionally, the first polarized beam is an optical signal in a TM mode or a TE mode, and the second polarized beam is an optical signal in a TM mode or a TE mode.

In the embodiment of the present invention, a mode is an electromagnetic field distribution that a waveguide of a specific shape can support. Mathematically, it is a guided mode solution of Maxwell's equation of this structure, and corresponds to an eigenvalue, ie, the effective refractive index. The effective index of refraction is an important parameter in the waveguide, which is related to the structure of the waveguide, material properties (refractive index), operating wavelength and mode order. Once these parametric properties of the waveguide are determined, the effective index of refraction for a mode of the waveguide will also be determined. The following description will be made by taking the TM mode and TE mode beams as examples.

The wavelength selective optical switch of the embodiment of the present invention can be used for the selection of polarized light with any polarization state, that is, the first polarized light beam and the second polarized light beam can be polarized light beams with any polarization mode, in particular, the first polarized light beam and the second polarized light beam can be polarized light beams with any polarization mode. One polarized light beam may be an optical signal in a TE mode or a TM mode, and the second polarized light beam may be an optical signal in a TE mode or a TM mode.

In the following description, the first polarized beam is an optical signal in the TM mode or the TE mode, and the second polarized beam is an optical signal in the TE mode as an example, but the present invention is not limited thereto.

As another embodiment, the first group of micro-ring resonators 321 may include one micro-ring resonator or a plurality of micro-ring resonators in cascade, and the second group of micro-ring resonators 322 may include one micro-ring resonator or stage connected multiple microring resonators.

Further, the number of microring resonators in the first group of microring resonators 321 is equal to the number of microring resonators in the second group of microring resonators 322 .

FIG. 4 shows a schematic structural diagram of a wavelength selective optical switch according to another embodiment of the present invention. As shown in FIG. 4 , the first group of micro-ring resonators 321 includes one micro-ring resonator, and the second group of micro-ring resonators 322 includes one micro-ring resonator as an example for illustration.

As another embodiment, the first polarized light beam and the second polarized light beam are polarized light beams of different modes, wherein the micro-ring resonators in the first group of micro-ring resonators 321 are micro-ring resonators that match the mode of the first polarized light beam. Ring resonators, the microring resonators in the second group of microring resonators 322 are microring resonators that match the mode of the second polarized light beam.

Mode matching means that the effective refractive indices in two adjacent waveguides are similar or equal. When the effective refractive indices of the two modes in the adjacent waveguides in the two spaces are similar or equal, the corresponding two modes satisfy the phase matching condition. Energy coupling and mode conversion can occur between modes that satisfy the phase matching conditions. The waveguides in the planar waveguide loop usually have the same height, so the width of the waveguide in adjacent regions determines the effective refractive index of a certain mode of the waveguide; the spacing between the waveguides in the adjacent region determines the energy coupling and mode conversion efficiency per unit length; The waveguide length (ie, the coupling length) of the adjacent region determines the overall energy coupling and mode conversion efficiency of the device.

By choosing appropriate waveguide spacing, waveguide width and waveguide length (ie coupling length) in adjacent regions, the optical energy of one mode in one waveguide can be fully coupled (converted) into the corresponding mode in another waveguide.

For example, as shown in FIG. 4 , the first polarized beam is a polarized beam of TM mode, then the micro-ring resonators in the first group of micro-ring resonators 321 can be designed as micro-ring resonators matching the TM mode; the second polarized beam For the polarized light beam in the TE mode, the micro-ring resonators in the second group of micro-ring resonators 322 can be designed as micro-ring resonators matching the TE mode.

At this time, when the optical signal in the TM mode passes through the first group of microring resonators 321, the target light beam satisfying the target wavelength _λi is coupled into the microring resonator matching the TM mode. When passing through the second group of microring resonators 322, the target beam satisfying the target wavelength λ _i is coupled into the microring resonators matching the TE mode.

As another embodiment, the polarization beam splitting unit 320 includes a polarization beam splitter, and the polarization beam combining unit 323 includes a third optical waveguide for coupling the first target beam and the second target beam.

That is to say, here the combining of the first target beam and the second target beam is done in a coupled optical waveguide (or referred to as an optical waveguide), and the first target beam and the second target beam are resonated from their corresponding microrings After the output ends of the device group are output, they respectively enter the optical waveguide for multiplexing, and finally output through the optical waveguide. At this time, there is no need to add other multiplexing devices.

Since the micro-ring resonators in the first group of micro-ring resonators 321 are micro-ring resonators matching the mode of the first polarized light beam, the first group of micro-ring resonators 321 can realize the The optical energy of the TM mode is completely coupled (converted) into the mode corresponding to the first group of microring resonators 321, and the first target beam of the TM mode coupled to the first group of microring resonators 321 is output to the third light In the waveguide; the micro-ring resonators in the second group of micro-ring resonators 322 are micro-ring resonators that match the mode of the second polarized light beam, then the second group of micro-ring resonators 322 can realize the second optical waveguide The optical energy of the TE mode in the TE mode is completely coupled into the mode corresponding to the second group of microring resonators 322, and the second target beam coupled to the TE mode of the second group of microring resonators 322 is output to the third light beam in the waveguide.

In this embodiment, the polarizing beam splitter 310 is used to split the input optical signal into a first polarized light beam and a second polarized light beam. The receiving end of the first group of micro-ring resonators 321 receives a first polarized light beam, and the first target light beam satisfying the target wavelength λ _i in the first polarized light beam is coupled into the first group of micro-ring resonators 321, and from the first polarized light beam. The output end of the first micro-ring resonator 321 outputs; the receiving end of the second group of micro-ring resonators 322 receives the second polarized light beam, and the second target light beam satisfying the target wavelength λ _i in the second polarized light beam is coupled to the in the second group of microring resonators 322 and output from the output terminal of the second microring resonator 322 . The output end of the first group of micro-ring resonators 321 outputs the first target beam to the third optical waveguide, and the output end of the second group of micro-ring resonators 322 outputs the second target beam to the third optical waveguide, The first target beam output from the first group of microring resonators 321 and the second target beam output from the second group of microring resonators 322 are combined in the third optical waveguide. The first target beam and the second target beam combined in the third optical waveguide are output.

Specifically, after the polarization-multiplexed and wavelength-division-multiplexed input beams (wavelengths λ ₁ , λ ₂ . . . λ _n ) are input into the polarization beam splitter 310 from the input port, the input optical signal can be transmitted to the polarization beam splitter 310 . The optical signals in the TM mode and the optical signals in the TE mode are divided into the two paths of optical signals, which respectively enter the wavelength selection unit 320 . The optical signals in the TM mode are transmitted to the input ends of the first group of microring resonators 321 , and the optical signals in the TE mode are transmitted to the input ends of the second group of microring resonators 322 . If the wavelength λ _i in the optical signal in the TM mode matches the resonance wavelength of the first group of microring resonators 321 , then the first group of microring resonators 321 matches the wavelength λ i in the optical signal in the TM mode that satisfies the target wavelength λ _i A target light beam is coupled into the first group of microring resonators 321; if the wavelength λ _i in the optical signal in the TE mode matches the resonance wavelength of the second group of microring resonators 322, then the second group of microring resonators 322 will A second target beam satisfying the target wavelength λ _i in the TE mode optical signal is coupled into the second group of microring resonators 322 .

The first target beam in the first group of micro-ring resonators 321 is output from the output end of the first group of micro-ring resonators 321 to the coupling region between the first group of micro-ring resonators 321 and the third optical waveguide; the second group The second target beam in the micro-ring resonator 322 is output from the output end of the second group of micro-ring resonators 322 to the coupling region of the second group of micro-ring resonators 322 and the third waveguide. The first target beam output from the first group of microring resonators 321 and the second target beam output from the second group of microring resonators 322 are combined in the third optical waveguide.

The first target beam and the second target beam combined in the third optical waveguide are output. The first target beam of the TM mode and the second target beam of the TE mode are combined to form a single-wavelength optical signal with polarization multiplexing. The wavelength of the output beam is λ _i , which satisfies the requirements of the first group of microring resonators 321 and the second The resonant wavelength λ _i of the set of microring resonators 322 .

In this way, the polarization state conversion between the first polarized light beam and the second polarized light beam is not required, which greatly reduces the polarization-dependent loss.

In addition, the difference between the transmission distances of the first polarized beam and the second polarized beam in the optical waveguide is significantly reduced, which can further reduce the polarization-dependent loss and also reduce the differential group velocity delay.

As another embodiment, the wavelength selective optical switch may further include a wavelength detection unit corresponding to the wavelength selection unit, and the wavelength detection unit is used for detecting the wavelength of the first target beam and the wavelength of the second target beam.

Specifically, in the wavelength selection unit 320, the wavelength detection unit is respectively provided at the output end of the first group of micro-ring resonators 321 and the output end of the second group of micro-ring resonators 322, and the first target The wavelength of the beam and the wavelength of the second target beam are detected.

Further, the wavelength detection unit includes a first optical coupler 341 located at the output end of the first group of microring resonators 321, a first optical detector 351 connected to the first optical coupler 341, and a first optical detector 351 located at the second optical coupler 341. A second optical coupler 342 at the output end of the group of microring resonators 322 , and a second optical detector 352 connected to the second optical coupler 342 .

FIG. 5 is a schematic structural diagram of a wavelength selective optical switch according to another embodiment of the present invention. In the i-th wavelength selection unit, a first optical coupler 341 can be set at the output end of the first group of micro-ring resonators 321, for extracting a small amount of optical signal energy from the trunk and sending it to the first optical detector 351 for monitoring. The first optical coupler 341 outputs part of the optical signal in the first target beam to the first optical detector 351, and the first optical detector 351 feeds back this part of the optical signal to the first group of microrings through an external feedback circuit The electrodes of the resonator 321 are driven to stabilize the wavelength of the downloaded optical signal by compensating in real time the amount of change of the resonance wavelength λ _i of the first group of micro-ring resonators.

Similarly, a second optical coupler 342 can be provided at the output end of the second group of microring resonators 322 to output part of the optical signal in the second target beam to the second optical detector 352, and the second optical detector 352 Through the external feedback circuit, this part of the optical signal is fed back to the electrode drive of the second group of microring resonators 322 to stabilize the downloaded optical signal by compensating the change of the resonance wavelength λ _i of the second group of microring resonators in real time. wavelength.

Therefore, by setting the wavelength monitoring unit, the wavelength of the optical signal downloaded by the wavelength selection unit can be stabilized by monitoring and compensating the target wavelength in real time.

FIG. 4 and FIG. 5 both illustrate that the first group of micro-ring resonators 321 includes one micro-ring resonator, and the second group of micro-ring resonators 322 includes one micro-ring resonator as an example. However, a plurality of microring resonators may be included in the first group of microring resonators 321 and the second group of microring resonators 322, respectively. 6 is a schematic structural diagram of a wavelength selective optical switch according to another embodiment of the present invention, the first group of microring resonators 321 may include two cascaded microring resonators, and the second group of microring resonators Two cascaded microring resonators may be included in resonator 322 . That is to say, one micro-ring resonator in the above wavelength selection unit can be replaced by a plurality of micro-ring resonators in cascade here, and other places can be unchanged. Thus, the operating spectral bandwidth of the optical switch can be expanded.

Optionally, the number of microring resonators in the first group of microring resonators is the same as the number of microring resonators in the second group of microring resonators. Therefore, the structural complexity of the wavelength selection unit is reduced, the path difference between the two polarized light beams when transmitted in the optical waveguide is reduced, and the polarization-related loss is reduced.

FIG. 7 shows a schematic structural diagram of a wavelength selective optical switch according to another embodiment of the present invention. As shown in FIG. 7 , the first group of micro-ring resonators 321 includes one micro-ring resonator, and the second group of micro-ring resonators 322 includes one micro-ring resonator as an example for illustration.

As another embodiment, the first polarized light beam and the second polarized light beam are polarized light beams of the same mode, wherein the micro-ring resonators in the first group of micro-ring resonators 321 and the micro-ring resonators in the second group of micro-ring resonators 322 Ring resonators, which are micro-ring resonators matched to the same mode.

For example, as shown in FIG. 7 , the first polarized light beam is a polarized light beam in the TE mode, then the micro-ring resonators in the first group of micro-ring resonators 321 can be designed as micro-ring resonators matching the TE mode; the second The polarized light beam is also the polarized light beam of the TE mode, so the micro-ring resonators in the second group of micro-ring resonators 322 are also designed as micro-ring resonators matching the TE mode.

At this time, when the optical signal in the TE mode passes through the first group of microring resonators 321, the target light beam satisfying the target wavelength _λi is coupled into the microring resonator matching the TE mode. When the optical signal passes through the second group of microring resonators 322, the target light beam satisfying the target wavelength λ _i is coupled into the microring resonator matching the TE mode.

Since the signals carried by the two beams with the same polarization state are different, if they are coupled together for processing, coherent constructive and coherent destructive interference effects will occur, which will lead to signal loss and cannot be demodulated. The ring resonator 321 and the second group of micro-ring resonators 322 respectively process two TE beams.

As another embodiment, the polarization beam splitting unit 310 includes a polarization beam splitting rotator, and the polarization beam combining unit 323 includes a polarization beam combining rotator.

In this embodiment, the input end of the first group of microring resonators 321 receives a first polarized light beam, and the first target light beam satisfying the target wavelength λ _i in the first polarized light beam is coupled to the first group of microring resonators 321 , the input end of the second group of microring resonators 322 receives the second polarized light beam, and couples the second target light beam satisfying the target wavelength λ _i in the second polarized light beam into the second group of microring resonators 322 . The output end of the first group of microring resonators 321 outputs the first target beam to the polarization beam combiner rotator 323 , and the output end of the second group of microring resonators 322 outputs the second target beam to the polarization beam combiner rotator 323 , the polarization beam combining rotator 323 is used for combining the first target beam and the second target beam, and the combined beam of the first target beam and the second target beam is output.

Specifically, after the polarization-multiplexed and wavelength-division-multiplexed input beams (wavelengths λ ₁ , λ ₂ . . . λ _n ) are input into the polarization rotation beam splitter 310 from the input port, the input optical signal is transmitted in the polarization beam splitter 310 It can be divided into two TE mode optical signals, wherein the first TE mode optical signal (first polarized beam) is the TE mode component in the original polarization multiplexed and wavelength division multiplexed optical signals, and the second TE mode component The mode optical signal (the second polarized beam) is obtained by converting the TM mode components in the original polarization multiplexed and wavelength division multiplexed optical signals, and the two optical signals enter the wavelength selection unit 320 respectively. If the wavelength λ _i in the optical signal in the first TE mode matches the resonance wavelength of the first group of microring resonators 321 , then the first group of microring resonators 321 in the optical signal in the TE mode satisfies the target wavelength The first target beam of λi is coupled into the first group of microring resonators 321; if the wavelength _λi in the optical signal of the second TE mode _conforms to the resonance wavelength of the second group of microring resonators 322, then the second The group of micro-ring resonators 322 couples a second target light beam satisfying the target wavelength λ _i in the optical signal of the TE mode into the second group of micro-ring resonators 322 .

The first target beam in the first group of microring resonators 321 is output from the output end of the first group of microring resonators to the polarization beam combining rotator 323; the second target beam in the second group of microring resonators 322 , output from the output end of the second group of microring resonators 322 to the polarization beam combining rotator 323 . The polarization beam combining rotator 323 is used to combine the first target beam and the second target beam. The first target beam output from the first group of microring resonators 321 and the second target beam output from the second group of microring resonators 322 are combined in the polarization beam combining rotator 323 .

In the first target beam and the second target beam after combining in the polarization beam combining rotator 323, the TE mode optical signal in the original input optical signal is converted into the TM mode optical signal through the polarization beam combining rotator 323, On the other hand, the optical signal in the TE mode of the other channel passes through the polarization beam combining rotator 323 and maintains the optical signal in the TE mode, and forms a polarization multiplexed single-wavelength optical signal after beam combining. The combined TE mode optical signal and the TM mode optical signal output by the polarization beam combining rotator 323 have a wavelength of λ _i , which satisfies the resonance of the first group of microring resonators 321 and the second group of microrings the resonant wavelength λ _i of the tuner 322 .

In this way, the number of polarization state conversions of the first polarized beam and the second polarized beam is the same, and the distances traveled by the first polarized beam and the second polarized beam in the optical waveguide are equal in the process from demultiplexing to combining. , so the polarization dependent loss and differential group velocity delay can be reduced.

Moreover, since the micro-ring resonators in the first group of micro-ring resonators 321 and the micro-ring resonators in the second group of micro-ring resonators 322 are micro-ring resonators for the same polarization mode, it is possible to process the same The same micro-ring resonator of the polarization state beam does not need to design two sets of different micro-ring resonators, which reduces the complexity of the system and the control complexity.

It should be understood that the polarization beam splitting unit in this embodiment may also include other devices capable of splitting and rotating the input optical signal, so as to realize dividing the input optical signal into two polarized beams such as the TE mode optical signal and the TM mode optical signal signal, and convert the TM mode optical signal into the TE mode optical signal. For example, the polarization beam splitting unit may include a polarization beam splitter and a polarization converter, or other optical structures capable of realizing this function. Likewise, the polarization beam combining unit may also include other devices capable of combining and rotating the input optical signal. The present invention does not limit this.

Optionally, the wavelength selective optical switch in this embodiment may further include a wavelength detection unit corresponding to the wavelength selection unit, and the wavelength detection unit is used to perform the wavelength detection on the wavelength of the first target beam and the wavelength of the second target beam. detection.

Further, the wavelength detection unit 320 includes a first optical coupler 341 located at the output end of the first group of microring resonators 321, a first optical detector 351 connected to the first optical coupler 341, and a first optical coupler 351 located at the first optical coupler 341. A second optical coupler 342 at the output end of the two groups of microring resonators 322 , and a second optical detector 352 connected to the second optical coupler 342 .

FIG. 8 is a schematic structural diagram of a wavelength selective optical switch according to another embodiment of the present invention. In the i-th wavelength selection unit, a first optical coupler 341 can be set at the output end of the first group of micro-ring resonators 321, for extracting a small amount of optical signal energy from the trunk and sending it to the first optical detector 351 for monitoring. The first optical coupler 341 outputs part of the optical signal in the first target beam to the first optical detector 351, and the first optical detector 351 feeds back this part of the optical signal to the first group of microrings through an external feedback circuit The electrodes of the resonator 321 are driven to stabilize the wavelength of the downloaded optical signal by compensating in real time the amount of change of the resonance wavelength λ _i of the first group of micro-ring resonators.

Similarly, a second optical coupler 342 can be provided at the output end of the second group of microring resonators 322 to output part of the optical signal in the second target beam to the second optical detector 352, and the second optical detector 352 Through the external feedback circuit, this part of the optical signal is fed back to the electrode drive of the second group of microring resonators 322 to stabilize the downloaded optical signal by compensating the change of the resonance wavelength λ _i of the second group of microring resonators in real time. wavelength.

Therefore, by setting the wavelength monitoring unit, the wavelength of the optical signal downloaded by the wavelength selection unit can be stabilized by monitoring and compensating the target wavelength in real time.

In this embodiment, FIG. 7 and FIG. 8 are described by taking the example that the first group of micro-ring resonators 321 includes one micro-ring resonator and the second group of micro-ring resonators 322 includes one micro-ring resonator as an example . However, a plurality of microring resonators may be included in the first group of microring resonators 321 and the second group of microring resonators 322, respectively. 9 is a schematic structural diagram of a wavelength selective optical switch according to another embodiment of the present invention, the first group of microring resonators 321 may include two cascaded microring resonators, and the second group of microring resonators Two cascaded microring resonators may be included in resonator 322 . That is to say, one micro-ring resonator in the above wavelength selection unit can be replaced by a plurality of micro-ring resonators in cascade here, and other places can be unchanged. Thus, the operating spectral bandwidth of the optical switch can be expanded.

The wavelength selective optical switch described in the above embodiment is described by taking a wavelength selective unit included in the wavelength selective optical switch as an example. In fact, the wavelength selective optical switch may include a plurality of such wavelength selective units to form Large scale optical switch matrix. The wavelength selective optical switch may further include the polarization beam splitting unit 310 as described in FIG. 2 to FIG. 9 , and n wavelength selection units as described in FIG. 2 to FIG. 9 , according to FIG. 2 to FIG. 9 , The first polarized beam output by the i-th wavelength selection unit that does not meet the target wavelength and the second polarized beam that does not meet the target wavelength enter the i+1-th wavelength selection unit respectively. The light beam that does not meet the target wavelength in the first polarized light beam passes through the first group of microring resonators in the i+1 wavelength selection unit to realize the selection of the light beam that meets the target wavelength λ _i+1 , and the second polarized light beam does not meet the target wavelength. The light beam meeting the target wavelength passes through the second group of microring resonators in the i+1 th wavelength selection unit, so as to realize the selection of the light beam meeting the target wavelength λ _i+1 . where i is a positive integer greater than zero and less than n.

It can be seen that, in the wavelength selective optical switch in the embodiment of the present invention, the first polarized beam and the second polarized beam have the same number of polarization state transitions, so the polarization-related loss can be greatly reduced, which is beneficial to the performance of the optical switching node.

In addition, the first group of micro-ring resonators and the second group of micro-ring resonators are symmetrically distributed along the input direction of the optical signal, and their processing processes for the two polarized beams are also consistent, so that the first polarized beam and the second polarized beam are The transmission distances in the optical waveguide are equal or similar, which can further reduce the polarization-dependent loss and at the same time reduce the differential group velocity delay.

Moreover, compared with the wavelength selective optical switch in the prior art, the wavelength selective optical switch in the embodiment of the present invention has a simple structure and a compact volume, and is suitable for forming a large-scale optical switch matrix.

It should be noted that, based on the wavelength selective optical switches of the embodiments of the present invention, optical switches with other modified connection relationships can be connected to form. For example, changing the direction of the incident light input port and the target output port in the wavelength selective optical switch in FIG. 2 to FIG. 9 can be achieved by changing the connection relationship of the wavelength selective unit accordingly, which will not be repeated here.

It should be understood that the first, second and third as well as various numerical numbers involved in this document are only for the convenience of description, and are not used to limit the scope of the embodiments of the present invention.

It should also be understood that, in various embodiments of the present invention, the size of the sequence numbers of the above-mentioned processes does not mean the sequence of execution, and the execution sequence of each process should be determined by its functions and internal logic, rather than the implementation of the present invention. The implementation of the examples constitutes no limitation.

It should also be understood that the term "and/or" in this document is only an association relationship for describing associated objects, indicating that there can be three kinds of relationships, for example, A and/or B, which can mean that A exists alone, and A and B exist at the same time. B, there are three cases of B alone. In addition, the character "/" in this document generally indicates that the related objects are an "or" relationship.

Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of the present invention.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described systems, devices and units may refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as independent products, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present invention can be embodied in the form of a software product in essence, or the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, Read-Only Memory (Read-Only Memory, referred to as "ROM"), Random Access Memory (Random Access Memory, referred to as "RAM"), magnetic disk or optical disk and other various A medium on which program code can be stored.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited to this. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention. should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (11)

1. a wavelength selective optical switch, is characterized in that, comprises polarization beam splitting unit and at least one wavelength selection unit, and described wavelength selection unit comprises two groups of micro-ring resonators and polarization beam combining unit, The polarization beam splitting unit is used to split the input beam into a first polarized beam and a second polarized beam, and transmit the first polarized beam to the first group of microring resonators in the two groups of microring resonators The input end of the second polarized light beam is transmitted to the input end of the second group of micro-ring resonators in the two groups of micro-ring resonators; the first group of microring resonators for coupling a first target beam of the first polarized light beams transmitted to the input end of the first group of microring resonators to the first group of microring resonators and output the first target beam coupled to the first group of micro-ring resonators to the polarization beam combining unit from the output end of the first group of micro-ring resonators. The wavelength of a target light beam is equal to the target wavelength corresponding to the wavelength selection unit; the second group of microring resonators for coupling the second target beam in the second polarized light beam transmitted to the input end of the second group of microring resonators to the second group of microring resonators and output the second target beam coupled to the second group of micro-ring resonators to the polarization beam combining unit from the output end of the second group of micro-ring resonators. The wavelength of the two target beams is equal to the target wavelength; The polarization beam combining unit is used for combining the first target beams received from the output ends of the first group of microring resonators and the light beams received from the output ends of the second group of microring resonators The second target beam is combined, and a beam obtained by combining the first target beam and the second target beam is output; wherein, Neither the first polarized light beam nor the second polarized light beam undergoes polarization state conversion or the number of polarization state conversions is the same. 2 . The wavelength selective optical switch according to claim 1 , wherein the polarization beam splitting unit passes through a first optical waveguide connecting the polarization beam splitting unit and the input end of the first group of microring resonators. 3 . , the first polarized light beam is transmitted to the input of the first group of microring resonators, and the light beams in the first polarized light beam not coupled to the first group of microring resonators are along the The first optical waveguide continues to transmit; The polarization beam splitting unit transmits the second polarized beam to the second group of microring resonators through a second optical waveguide connecting the polarization beam splitting unit and the input end of the second group of microring resonators The input end of the second polarized light beam, and the light beam in the second polarized light beam that is not coupled to the light beam in the second group of microring resonators continues to transmit along the second optical waveguide. 3. The wavelength selective optical switch according to claim 1 or 2, wherein the first polarized light beam and the second polarized light beam are polarized light beams of the same mode, wherein the first group of microrings The micro-ring resonators in the resonators and the micro-ring resonators in the second group of micro-ring resonators are micro-ring resonators matching the same mode. 4 . The wavelength selective optical switch according to claim 3 , wherein the polarization beam splitting unit comprises a polarization beam splitter rotator, and the polarization beam combining unit comprises a polarization beam combiner rotator. 5 . 5. The wavelength selective optical switch according to claim 1 or 2, wherein the first polarized light beam and the second polarized light beam are polarized light beams of different modes, wherein the first group of microrings The micro-ring resonators in the resonators are micro-ring resonators that match the mode of the first polarized beam, and the micro-ring resonators in the second group of micro-ring resonators are those that match the second polarized beam. mode-matched microring resonators. 6 . The wavelength selective optical switch according to claim 5 , wherein the polarization beam splitting unit comprises a polarization beam splitter, the polarization beam combining unit comprises a third optical waveguide, and the third optical waveguide for coupling the first target beam and the second target beam. 7. The wavelength selective optical switch according to claim 1 or 2, wherein the first group of micro-ring resonators comprises one micro-ring resonator or a plurality of micro-ring resonators that are cascaded, and the first group of micro-ring resonators The two groups of micro-ring resonators include one micro-ring resonator or a plurality of micro-ring resonators that are cascaded. 8. The wavelength selective optical switch according to claim 1 or 2, further comprising a wavelength detection unit corresponding to the wavelength selection unit, and the wavelength detection unit is used to detect the wavelength of the first target beam. The wavelength and the wavelength of the second target beam are detected. 9. The wavelength selective optical switch according to claim 8, wherein the wavelength detection unit comprises a first optical coupler located at the output end of the first group of microring resonators, and is connected to the the first photodetector connected to the first photocoupler, and a second optical coupler located at the output end of the second group of microring resonators, and a second optical detector connected to the second optical coupler. 10. The wavelength selective optical switch according to claim 1 or 2, wherein the first polarized beam is an optical signal in a TM mode or a TE mode, and the second polarized beam is an optical signal in a TE mode or a TM mode light signal. 11. The wavelength selective optical switch according to claim 1 or 2, wherein the at least one wavelength selection unit comprises a plurality of wavelength selection units, wherein each wavelength selection of the plurality of wavelength selection units The target wavelengths corresponding to the cells are different.

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