CN102725981B - Wave division multiplexing/de-multiplexing device, self-seeding fiber laser and optical network system - Google Patents

Abstract

The invention provides a wavelength division multiplexer/demultiplexer, a self-injection fiber laser and an optical network system. The wavelength division multiplexer/demultiplexer includes: a branch port, a first branch waveguide, an optical processing unit, at least two common waveguides, and at least two common ports, wherein the wavelength of the first common waveguide is the same as that of the second common waveguide The wavelength is the same, and the bandwidth of the first common waveguide is smaller than the bandwidth of the second common waveguide; the optical processing unit is used to receive the optical signal from the branch port through the first branch waveguide, and transfer the received optical signal from the first common waveguide through the first common waveguide The port is sent to the mirror to complete the intracavity filtering; the received optical signal is multiplexed from the second common port to the main optical fiber through the second common waveguide and sent to the opposite end device. The wavelength division multiplexing/demultiplexing device provided by the invention can simultaneously optimize the lasing performance and the signal multiplexing performance, and significantly improve the performance of the self-injection WDM-PON system.

Description

Wavelength division multiplexer/demultiplexer, self-injection fiber laser and optical network system

technical field

The embodiment of the present invention relates to communication technology, and in particular to a wavelength division multiplexing/demultiplexing device, a self-injecting fiber laser and an optical network system.

Background technique

WDM-PON (Wave Division Multiplexing Passive Optical Network, wavelength division multiplexing passive optical network) system uses AWG (Arrayed WaveguideGrating, referred to as Arrayed Waveguide Grating) or WGR (Waveguide Grating Router, Waveguide Grating Router) at the remote node Therefore, the wavelengths on the AWG or WGR ports connected to each ONU transceiver module are different, which will cause the lasers of each ONU transceiver module to be different (because different ONU transceiver modules require lasers with different wavelengths) , which is called a colored optical module in the field of optical communication. The use of colored optical modules in ONUs will lead to a series of colored problems, for example: the ONUs of each user's home are different and cannot be used universally; it brings great difficulties to the service provision of operators. Knowing which port (or which wavelength) of the AWG the user's optical fiber is connected to, it also brings storage problems to the operator.

In order to solve the problem of ONU coloring and ensure that all WDM-PON ONUs are the same, the industry has proposed the concept of WDM-PON colorless light source. The so-called colorless light source means that the ONU transceiver module has nothing to do with the wavelength, and the laser emission wavelength of the transceiver module can automatically adapt to the port wavelength of the connected AWG or WGR, so that it can be plugged into any AWG port or WGR port. That's it. In order to realize low-cost WDM-PON colorless lasers, the industry has proposed various solutions, such as self-seed WDM-PON systems. The self-seed WDM-PON system does not require expensive wide-spectrum seed light sources, has a simple structure, and has low-cost potential. In the self-seed WDM-PON system, the AWG at the transmitting end simultaneously assumes the functions of an intracavity filter at the transmitting end and a multiplexer for multiple users at the transmitting end. On the one hand, each channel of the AWG is an intracavity filter of the self-seed laser, which requires the filtering curve of the AWG channel to have a narrow 3dB bandwidth and have a maximum transmittance at the center wavelength of the channel; on the other hand, AWG also plays the multiplexing function of multiplexing the signals from multiple users' lasers onto the same backbone fiber, which requires the AWG to have a wide 3dB bandwidth and a relatively flat transmission curve in the channel.

However, the existing AWG has only one common waveguide, which cannot optimize the lasing performance and signal multiplexing performance of the transmitting end at the same time, so that the performance of the self-injection WDM-PON system based on the existing AWG is very limited and cannot meet the actual needs.

Contents of the invention

Embodiments of the present invention provide a wavelength division multiplexing/demultiplexing device, a self-injection fiber laser and an optical network system to solve the problem that the existing wavelength division multiplexing/demultiplexing device cannot simultaneously optimize the lasing of the self-injecting laser at the transmitting end performance and signal multiplexing performance deficiencies.

The first aspect of the present invention provides a wavelength division multiplexer/demultiplexer, including: a branch port, a first branch waveguide, an optical processing unit, at least two common waveguides, and at least two common ports; the optical processing unit passes The first common waveguide is connected to the first common port, and is connected to the second common port through the second common waveguide; the branch port is connected to the optical processing unit through the first branch waveguide; Wherein, the wavelength of the first common waveguide is the same as the wavelength of the second common waveguide, and the bandwidth of the first common waveguide is smaller than the bandwidth of the second common waveguide;

The optical processing unit is configured to receive an optical signal from the branch port through the first branch waveguide, and send the received optical signal from the first common port to the mirror through the first common waveguide , completing intracavity filtering; multiplexing the received optical signal from the second common port to a trunk optical fiber through the second common waveguide and sending it to the peer device.

The second aspect of the present invention provides a self-injection fiber laser, including: a laser, a wavelength division multiplexer/demultiplexer and a mirror; the wavelength division multiplexer/demultiplexer includes: a branch port, a first branch waveguide , an optical processing unit, at least two common waveguides and at least two common ports;

The optical processing unit is connected to the first common port through the first common waveguide, connected to the second common port through the second common waveguide, and the branch port is connected to the first common waveguide through the first branch waveguide. The optical processing unit is connected; wherein, the wavelength of the first common waveguide is the same as that of the second common waveguide, and the bandwidth of the first common waveguide is smaller than the bandwidth of the second common waveguide; the laser is connected to the branch port; the The mirror is connected to the first common port;

The optical processing unit is configured to receive the optical signal sent by the laser from the branch port through the first branch waveguide, and transfer the received optical signal from the first common waveguide to the first common waveguide. The port is sent to the reflector to complete intracavity filtering; the received optical signal is multiplexed from the second common port to the main optical fiber through the second common waveguide and sent to the peer device.

The third aspect of the present invention provides an optical network system, including: an optical line terminal, an optical distribution network, and an optical network unit, the optical line terminal is connected to the optical network unit through an optical distribution network, and it is characterized in that the optical line The terminal and/or the optical network unit includes the foregoing wavelength division multiplexer/demultiplexer.

In the wavelength division multiplexing/demultiplexing device, self-injecting fiber laser and optical network system provided by the embodiment of the present invention, the wavelength division multiplexing/demultiplexing device has two common waveguides with the same wavelength but different bandwidths, and the common waveguide with narrow bandwidth can be used. The waveguide performs intracavity filtering on the transmitted signal, and the common waveguide with wide bandwidth is used to multiplex the transmitted signal. Therefore, the wavelength division multiplexing/demultiplexing device provided by the embodiment of the present invention can simultaneously optimize the lasing performance and signal multiplexing With performance, the performance of self-injection WDM-PON system is significantly improved.

Description of drawings

FIG. 1A is a schematic structural diagram of a wavelength division multiplexing/demultiplexing device provided by an embodiment of the present invention;

1B is a schematic diagram of a connection mode between the AWG on the OLT side and the AWG on the user side when the AWG on the OLT side uses the AWG with two common ports provided by the embodiment of the present invention to send signals to the AWG on the user side;

1C is a schematic diagram of another connection mode between the AWG on the OLT side and the AWG on the user side when the AWG on the OLT side uses the AWG with two common ports provided by the embodiment of the present invention to send signals to the AWG on the user side;

1D is a schematic diagram of a connection mode between the OLT side AWG and the user side AWG when the user side AWG adopts the AWG with two common ports provided by the embodiment of the present invention to send signals to the user side AWG;

1E is a schematic diagram of another connection mode between the OLT side AWG and the user side AWG when the user side AWG adopts the AWG with two common ports provided by the embodiment of the present invention to send signals to the user side AWG;

FIG. 1F is a schematic diagram of the connection mode between the AWG on the OLT side and the AWG on the user side when both the AWG on the user side and the AWG on the OLT side adopt the AWG with two common ports provided by the embodiment of the present invention;

FIG. 2 is a schematic diagram of another AWG structure provided by an embodiment of the present invention;

3 is a schematic diagram of a connection mode between the AWG on the OLT side and the AWG on the user side when both the OLT side and the user side use the AWG with three common ports provided by the embodiment of the present invention;

FIG. 4 is a schematic structural diagram of an AWG with two common ports formed after improving an AWG with one common port provided by an embodiment of the present invention;

FIG. 5A is a schematic structural diagram of a self-injection fiber laser provided by an embodiment of the present invention;

FIG. 5B is a schematic structural diagram of another self-injection fiber laser provided by an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of an optical network system provided by an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of another network system provided by an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of another optical network system provided by an embodiment of the present invention.

Detailed ways

The wavelength division multiplexer/demultiplexer provided by the embodiment of the present invention may be an AWG or a WGR.

FIG. 1A is a schematic structural diagram of a wavelength division multiplexing/demultiplexing device provided by an embodiment of the present invention. As shown in FIG. 1A, the wavelength division multiplexer/demultiplexer includes: a branch port, a first branch waveguide 11, an optical processing unit 12, at least two common waveguides, and at least two common ports. The wavelength division multiplexer/demultiplexer may have multiple branch ports, and correspondingly, there may be multiple first branch waveguides 11 .

The optical processing unit is connected to the first common port A through the first common waveguide 13, connected to the second common port B through the second common waveguide 14, and the branch port is connected to the first common port through the first common waveguide 14. The branch waveguide is connected to the optical processing unit; wherein, the wavelength of the first common waveguide is the same as that of the second common waveguide, and the bandwidth of the first common waveguide is smaller than the bandwidth of the second common waveguide. The wavelength division multiplexer/demultiplexer provided by the embodiment of the present invention has at least two common ports with the same wavelength but different bandwidths.

an optical processing unit, configured to receive an optical signal from the branch port through the first branch waveguide, and send the received optical signal from the first common port to the mirror through the first common waveguide, and complete Intracavity filtering: multiplexing the received optical signal from the second common port to a trunk optical fiber through the second common waveguide and sending it to the peer device. Therefore, the wavelength division multiplexing/demultiplexing device provided by the embodiment of the present invention can be arranged at the local end of the telecommunication equipment room, and the branch port is connected with the laser in the OLT sending module; it can also be arranged at the user side, and the branch port is connected with the ONU sending module The laser in the laser or the laser in multiple ONT sending modules is connected.

When the light wave signal λ1, the light wave signal λ2...the light wave signal λN enters from the first branch port, the second branch port...the N branch port respectively, it is sent to the optical processing through the first branch waveguides connected to each branch port unit, after being processed by the optical processing unit, part of the energy of all light waves is output from the first common port A through the first common waveguide with a narrow bandwidth, and reflected back by the mirror connected to the first common port A, thus playing a role in the cavity Filtering function; another part of energy will be output from the second common port B through the common waveguide with wide bandwidth. Further, the narrow-bandwidth optical signal output from the first common port can be multiplexed to the main optical fiber network through the second common port B after being reflected back by the reflector.

Since the wavelength division multiplexer/demultiplexer provided by the present invention has at least two common waveguides, the optical processing unit can function as an intracavity filter through the first common waveguide, and the bandwidth design optimization of the first common waveguide can be carried out separately , the bandwidth is designed to be relatively narrow, and the transmission peak is consistent with the central wavelength of the channel, thereby improving the performance of the transmitted signal. And the second common waveguide can play the role of multiplexing all received optical signals of different wavelengths into one optical fiber, so the bandwidth of the common waveguide can be designed to be wider, and the transmission curve is very flat, so that it has a relatively low impact on the signal. All spectrums in have almost the same insertion loss, which can improve the performance of the multiplexed optical signal.

Further, the first common waveguide can be set as a Gaussian type, and the second common waveguide can be set as a flat type, so that the channel-to-wavelength transmission curve formed by the first common waveguide and each of the first branch waveguides is a Gaussian type. The transmission curve output by a common port A is Gaussian, the channel-to-wavelength transmission curve formed by the second common waveguide and each of the first branch waveguides is flat, and the transmission curve output by the second common port B is flat . Therefore, the first common port A may be a Gaussian port, and the second common port B may be a planar port.

Further, the optical processing unit is further configured to receive the optical signal sent by the peer device from the first common port through the first common waveguide, and respectively demultiplex the optical signal to the first branch waveguide. Alternatively, the optical processing unit is further configured to receive an optical signal sent by the peer device from the second common port through the second common waveguide, and respectively demultiplex the optical signal to the first branch waveguide . Therefore, the wavelength division multiplexing/demultiplexing device provided by the embodiment of the present invention can be arranged at the central office end of the telecommunication equipment room, and the branch port is connected with the receiver in the OLT sending module; it can also be arranged at the user side, and the branch port and the ONU send The receiver in the module or the receiver in the ONT receiving module is connected. In addition, the branch port can also be connected to the laser and the receiver respectively through WDM, and the periodicity of the wavelength division multiplexing/demultiplexing device is used to make the signals in different transmission directions use different channels in the wavelength division multiplexing/demultiplexing device. In the free transmission zone, signals in different transmission directions use different bands, so that the wavelength division/multiplexer can perform signal transmission and signal reception at the same time.

The following uses the AWG as an example to illustrate the connection mode between AWG1 on the OLT side and AWG2 on the user side.

In the case of forwarding the signal from the OLT side to the user side: AWG1 is the AWG with two public ports provided by the embodiment of the present invention, and AWG2 can be the AWG with two public ports provided by the present invention, or it can be the AWG with one public port AWG. The first common port A with narrow bandwidth on AWG1 is connected to a reflector. If AWG2 is the AWG with two public ports provided by the present invention, as shown in Figure 1B, the second public port B with wide bandwidth on AWG1 can be connected to the second public port B with wide bandwidth on AWG2 through the trunk optical fiber, AWG2 The common waveguide corresponding to the second common port B of the AWG1 demultiplexes the signal sent by AWG1 to each branch waveguide of AWG2; as shown in Figure 1C, the second common port B with a wide bandwidth on AWG1 can also be connected to AWG2 via a trunk fiber On the first common port A with narrow bandwidth, the common waveguide corresponding to the first common port A of AWG2 demultiplexes the signal sent by AWG1 to each branch waveguide of AWG2.

In the case of forwarding the user side signal to the OLT side: AWG2 is the AWG with two public ports provided by the embodiment of the present invention, and AWG1 can be the AWG with two public ports provided by the present invention, or it can be the AWG with one public port AWG. The first common port A with narrow bandwidth on AWG2 is connected to a reflector. If AWG1 is the AWG with two public ports provided by the present invention, as shown in Figure 1D, the second public port B with wide bandwidth on AWG2 can be connected to the second public port B with wide bandwidth on AWG1 through the trunk optical fiber; As shown in FIG. 1E , the second public port B with wide bandwidth on AWG2 may also be connected to the first public port A with narrow bandwidth on AWG1 via a trunk fiber.

As shown in Figure 1F, AWG1 is set at the local end of the telecommunications room, the branch port of AWG1 is connected to the OLT transceiver module, AWG2 is set on the user side, and the branch port of AWG2 is connected to the ONU transceiver module or the ONT transceiver module. Both AWG1 and AWG2 are AWGs with two public ports provided by the present invention, the second public port B with wide bandwidth on AWG2 is connected to the second public port B with wide bandwidth on AWG1 through the trunk optical fiber, and the periodicity of AWG can be utilized, Make the uplink signal and downlink signal use different free transmission regions (FSR) of AWG, that is, the uplink signal and downlink signal use different bands respectively, so that AWG1 can send signals to AWG2, and can also receive AWG2 signals. Similarly, AWG2 can Send signal to AWG1, also can receive AWG1 signal. Therefore, the AWG1 connected to the OLT can be used to multiplex the downlink signal and demultiplex the uplink signal at the same time, and the AWG2 connected to the ONU can also be used to demultiplex the downlink signal and multiplex the uplink signal at the same time.

The wavelength division multiplexer/demultiplexer provided by the embodiment of the present invention has two common waveguides with the same wavelength but different bandwidths. The common waveguide with a narrow bandwidth can be used to perform intracavity filtering on the transmitted signal, and the common waveguide with a wide bandwidth can be used for The transmitted signal is multiplexed. Therefore, the wavelength division multiplexing/demultiplexing device provided by the embodiment of the present invention can simultaneously optimize the lasing performance and the signal multiplexing performance, and significantly improve the performance of the self-injection WDM-PON system.

FIG. 2 is a schematic structural diagram of another wavelength division multiplexing/demultiplexing device provided by an embodiment of the present invention. As shown in FIG. 2 , the wavelength division multiplexer/demultiplexer provided in this embodiment also has a third common waveguide 15 and a third common port C. The third common port is connected to the optical processing unit through the third common waveguide. The wavelength of the third common waveguide is the same as that of the first common waveguide and the second common waveguide of the wavelength division multiplexer/demultiplexer at the opposite end.

The optical processing unit is further configured to receive an optical signal sent by the peer device from the third common port through the third common waveguide, and respectively demultiplex the optical signal to the first branch waveguide.

The wavelength division multiplexer/demultiplexer provided in this embodiment can demultiplex the signal received from the peer device to each first branch waveguide. The third common waveguide can be set as a Gaussian type or a flat type.

As shown in FIG. 3 , AWG1 and AWG2 are AWGs with three common ports provided by the embodiment of the present invention, wherein the wavelength of the third common port C of AWG1 is the same as that of the common ports A and B of AWG2. The second common port B of AWG1 is connected to a circulator, and then connected to the third common port C of AWG2 through the trunk fiber and another circulator, and the second common port B of AWG2 is connected to the second circulator, and then through the trunk fiber Connect with the third common port C of AWG1. Therefore, the signal sent from AWG1 to AWG2 is multiplexed to the trunk fiber through the second common port B, and when transmitted to AWG2 through the trunk fiber, it is demultiplexed to each first branch waveguide of AWG2 through the third common port C of AWG2. Similarly, the signal sent from AWG2 to AWG1 is multiplexed to the trunk fiber through the second common port B, and when transmitted to AWG1 through the trunk fiber, it is demultiplexed to each first branch waveguide of AWG1 through the third common port C of AWG1.

The wavelength division multiplexer/demultiplexer with two common ports provided by the embodiment of the present invention may be composed of two wavelength division multiplexer/demultiplexers with different bandwidths and multiple optical beam splitters. Taking AWG as an example, a 2×N AWG is composed of two different bandwidth AWGs and multiple optical beam splitters. Wherein, AWG1 and AWG2 may respectively be AWGs having a common waveguide. The number of branch waveguides of AWG1 is the same as the number of branch waveguides of AWG2, and the number of optical beam splitters is the same as the number of branch waveguides of AWG1. The common waveguide of AWG1 has a narrower bandwidth than the common waveguide of AWG2. Each branch waveguide is connected with an optical beam splitter, and each optical beam splitter is connected to AWG1 and AWG2 respectively. Correspondingly, an AWG with three common ports can be composed of three AWGs with one common port and multiple optical beam splitters.

In addition, a wavelength division multiplexer/demultiplexer with one common port can also be improved to form the wavelength division multiplexer/demultiplexer with two common ports provided by the embodiment of the present invention. Specifically, on the basis of the embodiment corresponding to FIG. 1A , the wavelength division multiplexing/demultiplexing device further includes: an optical beam splitter and a second branch waveguide. The branch port is connected to the first branch waveguide, the first branch waveguide is connected to the optical beam splitter, and the optical beam splitter is connected to the optical processing unit through the second branch waveguide. The optical beam splitter is configured to send the optical signals received by the first branch waveguide to the optical processing unit through the second branch waveguide respectively for processing. The AWG is taken as an example below to illustrate a wavelength division multiplexer/demultiplexer with two common ports formed by improving a wavelength division multiplexer/demultiplexer with one common port.

FIG. 4 is a schematic structural diagram of an AWG with two common ports formed by improving an AWG with one common port provided by an embodiment of the present invention. As shown in Figure 4, the AWG provided by this embodiment includes: a plurality of branch waveguides 41, a plurality of optical beam splitters 42, a first free propagation range (Free propagation range, FPR for short) 43, an arrayed waveguide 44 composed of several waveguides And the second free transmission area 45 and two common waveguides. Wherein, the optical beam splitter, the first free transmission area, the array waveguide and the second free transmission area form an optical processing unit. The first free transfer area and the second free transfer area may be rounded in shape.

Each branch waveguide is connected to the first free transmission area, and the first free transmission area is connected to the second free transmission area through the array waveguide. Each branch waveguide is set as a Y branch, that is, each branch waveguide is decomposed into two branch waveguides by an optical beam splitter, after decomposition, the branch waveguide is connected to the first free transmission area, and the second free transmission area is connected to the second free transmission area A common waveguide 46 and a second common waveguide 47.

The optical signals entering each branch waveguide are incident on a point of the first free transmission area, and these optical signals generate an imaging point on the second free transmission area, and the second free transmission area is connected to a common waveguide at this point. After a Y branch is added to each of the branch waveguides, a part of the optical signal entering from each branch waveguide is incident on another point in the first free transmission area, and this part of the optical signal is in the second free transmission area. Imaging also moves to another point, adding a common waveguide to this new imaging point. Therefore, the two imaging points of the second free transmission area are respectively connected to a common waveguide. Among them, increase the planarization design for the wide-bandwidth common waveguide, for example, design the wide-bandwidth common waveguide into a tapered shape, so that the width of the common waveguide on the side connected to the Rowland circle is greater than the width of the branch waveguide, so that the wide-bandwidth common waveguide The transmission curve of the common waveguide becomes flat. Other AWG planarization techniques may also be used, for example, setting the common waveguide with wide bandwidth as a multimode waveguide structure (Multimode Interferometer, MMI for short), or setting it as a Mach-Zehnder interferometer structure (Mach-Zehnder interferometer, MZI for short). Further, in order to reduce the crosstalk of the added branch waveguides to adjacent waveguides, the radius of the AWG Rowland circle can be appropriately increased, so that the distance between the original branch waveguides on the Rowland circle is larger.

Further, another common waveguide, ie, the third common waveguide, can be connected to the second free transmission area, so that the AWG can provide three common ports to the outside.

FIG. 5A is a schematic structural diagram of a self-injection fiber laser provided by an embodiment of the present invention. As shown in FIG. 5A , this embodiment includes: a laser 51 , a wavelength division multiplexer/demultiplexer 52 and a mirror 53 . Wherein, the wavelength division multiplexer/demultiplexer 52 may be an AWG or a WGR; the laser 51 may be a wide-spectrum gain laser.

The wavelength division multiplexer/demultiplexer 52 includes: a branch port, a first branch waveguide, an optical processing unit, at least two common waveguides and at least two common ports, and the optical processing unit communicates with the first common waveguide through the first common waveguide The first common port is connected to the second common port through the second common waveguide, and the branch port is connected to the optical processing unit through the first branch waveguide. Wherein, the wavelength of the first common waveguide is the same as that of the second common waveguide, and the bandwidth of the first common waveguide is smaller than the bandwidth of the second common waveguide; the laser is connected to the branch port; the mirror is connected to the The first public port is connected. Wherein, the number of lasers 51 is the same as the number of the first branch waveguides. The second common port B is the optical signal output port of the self-injection laser.

The optical processing unit is configured to receive the optical signal sent by the laser from the branch port through the first branch waveguide, and transfer the received optical signal from the first common waveguide to the first common waveguide. The port is sent to the reflector to complete intracavity filtering; the received optical signal is multiplexed from the second common port to the main optical fiber through the second common waveguide and sent to the peer device.

The specific function and structure of the wavelength division multiplexer/demultiplexer 52 can be referred to the description in the corresponding embodiment in FIG. 1A , which will not be repeated here.

Further, the reflection mirror 53 may be a partial reflection mirror or a total reflection mirror. It is used to reflect all or part of the optical signal output from the common port A back. Further, the reflector is a Faraday Rotator Mirror (FRM for short). For example, adding a single-pass 45° Faraday rotator in front of the mirror forms the FRM. After the broad-spectrum spontaneous emission spectrum emitted by the broad-spectrum gain laser 51 is reflected by the FRM, its polarization direction will be rotated by 90°. The broad-spectrum spontaneous emission spectrum emitted by the broad-spectrum gain laser in TE mode becomes TM mode after being reflected by FRM, and the broad-spectrum spontaneous emission spectrum emitted in TM mode becomes TE mode after TE reflection. Based on this principle, the polarization gain dependence in the self-injection laser can be weakened, and it is also more conducive to improving the system's ability to resist random polarization interference.

Among them, the broad-spectrum gain laser can be an LD laser with a modulation function, such as a Reflective Semiconductor Optical Amplifier (RSOA) laser, or an injection-locked Fabry-Perot (Fabry-Perot) laser with low front-end reflection. Laser Diode, referred to as IL FP-LD) laser, or other lasers. For example, the wavelength division multiplexer/demultiplexer in the self-injection fiber laser is AWG. The wide-spectrum gain laser first emits broad-spectrum amplified spontaneous emission (Amplified Spontaneous Emission, referred to as ASE). ASE passes through one of the branch ports of the AWG. Only the light within the passband range of the branch port channel of the AWG can pass through, and the light outside the passband is filtered or lost, and only the light within the channel range corresponding to the first common port A can be reflected by the mirror and injected into the laser again In this way, multiple round trips form resonant amplification. Finally, the self-injection laser works at the transmission peak wavelength determined by the A channel of the AWG common port. At the same time, part of the energy of the lased optical signals formed by the gain media connected to all the branch ports will be emitted through the second common port B. Since the first common port A can only function as an intracavity filter, its bandwidth design can be optimized separately, and its bandwidth can be designed to be relatively narrow, and the transmission peak is consistent with the central wavelength of the channel, thereby improving the performance of the transmitted signal. And the second common port B can only multiplex the lights of different wavelengths from the gain media of all branches into one optical fiber, so its 3dB bandwidth can be designed to be wide, and the transmission curve is very flat, making it relatively All spectrums in the signal have almost the same insertion loss, thus improving the performance of the multiplexed optical signal.

Further, in order to prevent some stray reflected light on the trunk fiber from entering the cavity and affecting the resonance of the self-injection laser, an optical isolator or an optical circulator can be added between the trunk fiber and the second common port B.

As shown in FIG. 5B , the wavelength division multiplexer/demultiplexer 52 is also provided with a third common port C. The third common port is connected to the optical processing unit through the third common waveguide. Wherein, the optical processing unit is further configured to receive the optical signal sent by the peer device from the third common port through the third common waveguide, and respectively demultiplex the optical signal to the first branch waveguide . The specific function and structure of the wavelength division multiplexer/demultiplexer 52 may refer to the description in the corresponding embodiment in FIG. 2 , and details are not repeated here.

FIG. 6 is a schematic structural diagram of an optical network system provided by an embodiment of the present invention. As shown in FIG. 6 , an optical line terminal 61 , an optical distribution network 62 and an optical network unit 63 , the optical line terminal 61 is connected to the optical network unit 63 through the optical distribution network 62 . Wherein, the optical line terminal 61 includes a wavelength division multiplexer/demultiplexer with two common ports shown in FIG. A wavelength division multiplexer/demultiplexer with a common port; or, as shown in 8, both the optical line terminal and the optical network unit include the wavelength division multiplexer/demultiplexer with two common ports shown in FIG. 1 . Further, the wavelength division multiplexer/demultiplexer in FIG. 6 , FIG. 7 or FIG. 8 may also be a wavelength division multiplexer/demultiplexer with three common ports as shown in FIG. 2 . For the specific connection manner, refer to the descriptions in the corresponding embodiments in FIG. 1A to FIG. 1F , which will not be repeated here.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.

Claims (10)

1. a Wavelength division multiplexer/demultiplexer, is characterized in that, comprising: branch port, the first branch-waveguide, light processing unit, at least two common waveguide and at least two public ports; Described smooth processing unit is connected with the first public port by the first common waveguide, is connected with the second public port by the second common waveguide; Described branch port is connected with described smooth processing unit by described the first branch-waveguide; Wherein, the wavelength of the first common waveguide is identical with the wavelength of the second common waveguide, and the bandwidth of the first common waveguide is less than the bandwidth of the second common waveguide;

Described smooth processing unit, for by described the first branch-waveguide from described branch port receiving optical signals, by described the first common waveguide, the described light signal receiving is sent to speculum from described the first public port, complete filtering in chamber; By described the second common waveguide, the light signal of described reception is multiplexed into trunk optical fiber and sends to opposite equip. from described the second public port.

2. Wavelength division multiplexer/demultiplexer according to claim 1, is characterized in that, described Wavelength division multiplexer/demultiplexer also comprises: beam splitter and the second branch-waveguide; Described the first branch-waveguide is connected with described beam splitter, and described beam splitter is connected with described smooth processing unit by described the second branch-waveguide; Described beam splitter, for sending to described smooth processing unit to process by described the second branch-waveguide respectively the described light signal receiving.

3. according to Wavelength division multiplexer/demultiplexer described in claim 1 or 2, it is characterized in that, described Wavelength division multiplexer/demultiplexer also comprises: the 3rd common waveguide and the 3rd public port; Described the 3rd public port is connected with described smooth processing unit by described the 3rd common waveguide; Wherein, described smooth processing unit, also, for receiving from described the 3rd public port the light signal that opposite equip. sends by described the 3rd common waveguide, is demultiplexed into respectively described the first branch-waveguide by described light signal.

4. according to Wavelength division multiplexer/demultiplexer described in claim 1 or 2, it is characterized in that, described smooth processing unit, also, for receiving from described the first public port the light signal that opposite equip. sends by described the first common waveguide, is demultiplexed into respectively described the first branch-waveguide by described light signal; Or described smooth processing unit, also, for receiving from described the second public port the light signal that opposite equip. sends by described the second common waveguide, is demultiplexed into respectively described the first branch-waveguide by described light signal.

5. from an injection fibre laser, comprising: laser, Wavelength division multiplexer/demultiplexer and speculum; It is characterized in that, described Wavelength division multiplexer/demultiplexer comprises: branch port, the first branch-waveguide, light processing unit, at least two common waveguide and at least two public ports;

Described smooth processing unit is connected with the first public port by the first common waveguide, is connected with the second public port by the second common waveguide; Described branch port is connected with described smooth processing unit by described the first branch-waveguide; Wherein, the wavelength of described the first common waveguide is identical with the wavelength of the second common waveguide, and the bandwidth of the first common waveguide is less than the bandwidth of the second common waveguide; Described laser is connected with described branch port; Described speculum is connected with described the first public port;

Described smooth processing unit, for receiving from described branch port the light signal that described laser sends by described the first branch-waveguide, by described the first common waveguide, the described light signal receiving is sent to speculum from described the first public port, complete filtering in chamber; By described the second common waveguide, the light signal of described reception is multiplexed into trunk optical fiber and sends to opposite equip. from described the second public port.

6. according to claim 5 from injection fibre laser, it is characterized in that, described Wavelength division multiplexer/demultiplexer also comprises: beam splitter and the second branch-waveguide; Described the first branch-waveguide is connected with described beam splitter, and described beam splitter is connected with described smooth processing unit by described the second branch-waveguide; Described beam splitter, for sending to described smooth processing unit to process by described the second branch-waveguide respectively the described light signal receiving.

According to described in claim 5 or 6 from injection fibre laser, it is characterized in that, described Wavelength division multiplexer/demultiplexer also comprises: the 3rd common waveguide and the 3rd public port; Described the 3rd public port is connected with described smooth processing unit by described the 3rd common waveguide; Wherein, described smooth processing unit, also, for receiving from described the 3rd public port the light signal that opposite equip. sends by described the 3rd common waveguide, is demultiplexed into respectively described the first branch-waveguide by described light signal.

According to described in claim 5 or 6 from injection fibre laser, it is characterized in that, described smooth processing unit, also, for receiving from described the first public port the light signal that opposite equip. sends by described the first common waveguide, is demultiplexed into respectively described the first branch-waveguide by described light signal; Or described smooth processing unit, also, for receiving from described the second public port the light signal that opposite equip. sends by described the second common waveguide, is demultiplexed into respectively described the first branch-waveguide by described light signal.

9. according to claim 7 from injection fibre laser, it is characterized in that, described speculum is faraday rotator mirror.

10. an optical network system, comprise: optical line terminal, optical distribution network and optical network unit, described optical line terminal is connected with described optical network unit by optical distribution network, it is characterized in that, described optical line terminal and/or described optical network unit comprise any Wavelength division multiplexer/demultiplexer as described in claim 1-4.