CN119788101A - A free space optical transmitting and receiving module - Google Patents

Abstract

The invention relates to a free-space optical transmitting and receiving module, comprising a laser transmitting module, an optical circulator, a micro-motion lens and a laser receiving module; the laser transmitting module is used for transmitting laser signals; the optical circulator comprises a first port, a second port and a third port; the laser is input from the first port and then output from the second port, and is input from the second port and then output from the third port; the micro-motion lens is provided with a micro-displacement driver with two degrees of freedom of the X-axis and the Y-axis, or a micro-displacement driver with three degrees of freedom of the X-axis, the Y-axis and the Z-axis; the micro-motion lens of the invention shares a component for transmitting and receiving, thereby reducing errors and improving capture and tracking accuracy; the micro-displacement driver is provided to realize two-dimensional micro-displacement of the micro-motion lens in an XY plane, thereby generating far-field space scanning; on the one hand, the scanning range can be expanded; on the other hand, the micro-displacement driver can be used for receiving signals in a large range at multiple angles, thereby improving receiving accuracy and reducing alignment difficulty.

Description

Free space light transmitting and receiving module

Technical Field

The present invention relates to the field of optical technologies, and in particular, to a free space light emitting and receiving module.

Background

In a wireless optical communication system, a communication subsystem, a capture alignment tracking subsystem and the capture alignment tracking subsystem are not completely coaxial, so that precise coaxiality of multiple optical axes is required to be ensured, wherein the precise coaxiality comprises a, capture/coarse tracking detection visual axis coaxiality, b, precise tracking detection visual axis coaxiality, c, communication visual axis coaxiality. Not only is the structure complex, but also the overall design, processing and debugging difficulties of the wireless optical communication system are very large, and the cost cannot be reduced.

In the prior art, a part of the received communication light energy is used as the beacon light energy, so that the capturing, aligning and tracking in the wireless optical communication process are completed. The scheme can also simplify the structure, reduce the volume, the weight and the energy consumption. Because the communication light receiving optical system can only focus a part of the received light signal on the photodetector with the micron-scale, the light energy loss is originally large, and the light signal is further weakened after a part is separated for capturing alignment tracking, the light signal is further weakened, the light emitting intensity is increased, and the weight, the volume and the power consumption of the device are increased.

As for the detection of the detection beam on the two-dimensional plane, the current common method generally uses a mechanical rotation, a rotation polygon mirror or a MEMS galvanometer scanning method, and in order to accurately capture and track, high-precision position adjustment and control are required, and high requirements are put on the adjustment precision and control mode of the product.

Disclosure of Invention

In order to solve the above-mentioned problems of the prior art, the present invention provides a free space light emitting and receiving module.

In order to achieve the above purpose, the main technical scheme adopted by the invention comprises the following steps:

a free-space light emitting and receiving module, comprising:

the laser emission module is used for emitting laser signals;

the optical circulator comprises a first port, a second port and a third port, wherein the first port is used for receiving a laser signal emitted by the laser emitting module;

The micro lens is arranged at the second port of the optical circulator and used for receiving the laser signal which enters the second port from the first port and transmitting the laser signal to the outside, and/or is used for receiving the external laser signal and outputting the external laser signal from the third port after inputting the external laser signal into the second port;

and the laser receiving module is arranged at the third port of the optical circulator and is used for receiving the laser signal input from the second port.

Further, the laser emission module comprises an emission optical fiber, and a micro-displacement driver with two degrees of freedom of an X axis and a Y axis is arranged on the end head of the emission optical fiber.

Further, the laser receiving module comprises a receiving optical fiber, and a micro-displacement driver with two degrees of freedom of an X axis and a Y axis is arranged on the end head of the receiving optical fiber.

Further, the optical circulator comprises a first polarization beam splitter prism, a light rotating sheet and a second polarization beam splitter prism which are arranged along the light path direction, and a light filter is arranged on one side, opposite to the third port, of the first polarization beam splitter prism.

Further, a power amplification module is arranged between the laser emission module and the optical circulator.

Furthermore, a low-noise pre-optical amplifier is arranged between the laser receiving module and the optical circulator.

Further, the micro-displacement driver is driven by a piezoelectric ceramic or a piezoelectric motor.

Furthermore, the emergent end of the micro lens is provided with an auto-collimation lens or a beam expander.

Further, the laser transmitting module and the laser receiving module are internally provided with first collimating lenses.

The micro-lens has the advantages that the micro-lens is used as a transmitting and receiving end and used for transmitting laser signals to the outside, on the one hand, the micro-lens is used for receiving external laser signals, on the other hand, the transmitting and receiving share one component, so that the error can be reduced, the capturing tracking precision is improved, two-dimensional micro-displacement of the micro-lens in an XY plane can be realized through the arrangement of the micro-displacement driver, far-field space scanning is generated, nano-scale to micro-scale displacement can be realized through the micro-displacement generation on a focal plane or a virtual focal plane, the angle change of an output beam of the micro-lens is formed, on the one hand, the scanning range can be enlarged, on the other hand, the micro-lens can be used for receiving signals in a large range at multiple angles, the receiving precision is improved, the alignment difficulty is reduced, the zooming effect can be realized through the increase of the movement freedom degree of a Z axis, the micro-lens can be moved along the right side of the Z axis in the capturing positioning process in the earlier stage, the capturing area is increased, the capturing is realized, the micro-lens is moved along the left side of the Z axis after capturing, the micro-lens is captured, the energy utilization rate is improved, and the light utilization rate is improved, and the effective utilization rate of the light beam is changed in the Z-axis direction.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some examples of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of an embodiment of the present invention;

FIG. 2 is a schematic diagram of another embodiment of the present invention;

FIG. 3 is a schematic view of another embodiment of the present invention;

FIG. 4 is a schematic view of the optical path of the micro lens of the present invention moving in the Z-axis;

reference numerals illustrate:

100. The device comprises a laser emitting module, a first collimating lens, a 110, an emitting optical fiber, a 120, a power amplifying module, a 200, an optical circulator, a 201, a first port, a 202, a second port, a 203, a third port, a 210, a first polarization beam splitting prism, a 220, an optical rotation sheet, a 230, a second polarization beam splitting prism, a 240, an optical filter, a 300, a micro lens, a 301, a focal plane, a 400, a laser receiving module, a 410, a receiving optical fiber, a 420, a low-noise pre-optical amplifier, a 500, a beam expander and a 500' auto-collimating lens.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of 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, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, based on the embodiments of the invention, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the invention. Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, based on the embodiments of the invention, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the invention.

In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "inner", "outer", "front", "rear", "both ends", "one end", "the other end", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific direction, be configured and operated in the specific direction, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, unless explicitly stated and limited otherwise, the terms "mounted," "configured to," "connected," and the like are to be construed broadly as, for example, "connected" may be fixedly connected, may be detachably connected, or integrally connected, may be mechanically connected or electrically connected, may be directly connected or indirectly connected through an intermediate medium, and may be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

As shown in fig. 1, the free space optical transmitting and receiving module comprises a laser transmitting module 100, an optical circulator 200, a micro lens 300 and a laser receiving module 400, wherein the laser transmitting module 100 is used for transmitting laser signals, the optical circulator 200 comprises a first port 201, a second port 202 and a third port 203, laser is input from the first port 201, then output from the second port 202, input from the second port 202 and then output from the third port 203, the first port 201 is generally used for receiving the laser signals transmitted by the laser transmitting module 100, the Y-axis direction in the figure is actually perpendicular to the paper surface direction, and the Y-axis direction in the figure is only schematic;

The micro lens 300 is used as a transmitting and receiving end, and is used for transmitting laser signals to the outside on one hand and receiving external laser signals on the other hand, and the transmitting and receiving parts share one part, so that errors can be reduced, and the capturing and tracking precision can be improved;

in an embodiment, the micro lens 300 may be configured as a converging lens, and an auto-collimation lens 500' is additionally disposed at the exit end of the micro lens 300, so as to ensure collimation of the exiting laser, and the converging lens can converge the laser signal incident from the outside after capturing, so as to reduce the light beam, and reduce the capturing difficulty;

in an embodiment, the micro lens 300 may be configured as a converging lens, and the beam expander 500 is further disposed at the exit end of the micro lens 300, so that the coverage of the outgoing laser signal can be increased and the laser signal can be captured in a large range by the beam expander 500, thereby reducing the capturing difficulty;

The micro-displacement driver can realize the displacement from nano level to micro level, and the angle change of the output light beam of the micro-lens 300 is formed through the generation of micro displacement on the focal plane 301 or the virtual focal plane 301, so that the scanning range can be enlarged, the signal receiving can be performed in a large range at multiple angles, the receiving precision is improved, and the alignment difficulty is reduced;

In an embodiment, the micro-lens 300 is provided with a micro-displacement driver with three degrees of freedom of an X axis, a Y axis and a Z axis, and can realize the zooming effect by increasing the degree of freedom of movement of the Z axis, the micro-lens 300 is provided with a converging lens, and an alignment lens is additionally arranged at the emergent end of the micro-lens 300, as shown in fig. 4, the auto-collimating lens 500 emits collimated light in the B state, when the micro-lens 300 moves along the right side of the Z axis, the emergent light of the auto-collimating lens 500 'is in the A state, the range of the emergent light is larger, the effect of a beam expander can be realized, when the micro-lens 300 moves along the left side of the Z axis, the emergent light of the auto-collimating lens 500' is in the C state, the beam can be reduced, the energy utilization rate can be improved, and in the Y axis, and the utilization rate of the Y axis can be improved, and the utilization rate of the micro-lens 300 can be changed in the Z axis direction when the micro-lens 300 moves along the left side of the Z axis, and the utilization rate of the Y axis can be improved, and the utilization rate of the micro-lens 300 can be quickly aligned and captured;

in one embodiment, the laser emitting module 100 comprises an emitting optical fiber 110, wherein the end of the emitting optical fiber 110 is provided with a micro-displacement driver with two degrees of freedom of an X axis and a Y axis;

In an embodiment, the laser receiving module 400 comprises a receiving optical fiber 410, wherein the end of the receiving optical fiber 410 is provided with a micro-displacement driver with two degrees of freedom of an X axis and a Y axis, the micro-displacement driver is arranged on the receiving optical fiber 410 and is better than the micro-displacement driver arranged on the transmitting optical fiber 110, the micro-displacement driver controls the independent scanning movement of the receiving optical fiber 410, and can realize faster laser signal capturing in cooperation with the micro-displacement of the micro-lens 300;

In one embodiment, the micro-displacement driver is driven by a piezoelectric ceramic or a piezoelectric motor; the piezoelectric ceramic is generally stuck on the surface of the micro lens 300 by adopting a sheet structure, and the output displacement of the piezoelectric ceramic is controlled by controlling the change of voltage or current, so as to realize the micro displacement of the micro lens 300; when the micro-displacement driver is the micro-displacement driver with three degrees of freedom of the X axis, the Y axis and the Z axis, the piezoelectric ceramics are arranged for controlling the micro-displacement of the micro-lens 300 in the directions of the X axis, the Y axis and the Z axis respectively, and the displacement in each direction can be controlled independently;

In an embodiment, the piezoelectric ceramic plate can be replaced by a piezoelectric motor to form a micro-displacement driver, a plurality of piezoelectric motors can be arranged to realize displacement control in a plurality of directions, in an embodiment, the piezoelectric motor can realize rotary motion which also comprises motion in two degrees of freedom of an X axis and a Y axis, so that when only one piezoelectric motor is arranged in an embodiment, the micro-lens 300 can also realize motion in two degrees of freedom in an XY plane, and the core working principle of the piezoelectric motor is based on the inverse piezoelectric effect of piezoelectric materials as a precise piezoelectric device. This effect allows the piezoelectric material to undergo a small deformation, i.e. a small amplitude of vibration, under the action of an external electric field. In piezoelectric motors, the stator is typically made of piezoelectric material, and when a voltage signal of a specific frequency is applied, the stator generates a slight vibration in this frequency range. These minute vibrations are skillfully converted into macroscopic motions of the mover (micro lens 300) by means of a well-designed structure and friction. The piezoelectric motor can drive the rotor to realize expected macroscopic motion through micro vibration of the stator through a series of complex mechanical conversion no matter the piezoelectric motor moves linearly or rotates. For example, among the numerous piezoelectric motor designs, the L1B2 piezoelectric motor is a typical example. The design characteristic of the piezoelectric motor is that the frequency points of a first-order extension mode and a second-order bending mode of the piezoelectric motor are very close through accurate structural adjustment. When a drive signal with a specific frequency is externally loaded, the first-order extension vibration and the second-order bending vibration of the stator are coupled with each other to form an elliptical motion track of the friction head. During this elliptical movement, a strong squeezing action is created between the friction head of the stator and the mover. This squeezing action is further enhanced by the pre-tightening force, thereby creating a sufficiently large friction force between the two. This friction is the primary source of power to drive the mover to move, enabling precise linear or rotational movement of the mover under the drive of the piezoelectric motor.

Similarly, the micro-displacement drivers disposed on the transmitting optical fiber 110 and the receiving optical fiber 410 may be driven by the above scheme;

In one embodiment, the optical circulator 200 comprises a first polarization splitting prism 210, an optical rotation sheet 220 and a second polarization splitting prism 230 which are arranged along the optical path direction, wherein an optical filter 240 is arranged on one side of the first polarization splitting prism 210 opposite to the third port 203, the optical circulator 200 generates more than 60dB of Tx (transmitting signal) and Rx crosstalk (receiving signal), the optical filter 240 generates more than 40dB of lambda 1 and lambda 2 isolation, and the whole system has more than 100dB of Tx and Rx crosstalk;

As shown in fig. 2, in an embodiment, the laser emitting module 100 and the laser receiving module 400 are both provided with a first collimating lens 101;

As shown in fig. 3, in an embodiment, a power amplifying module 120 is disposed between the laser emitting module 100 and the optical circulator 200, a low noise pre-optical amplifier 420 is disposed between the laser receiving module 400 and the optical circulator 200, and after the rx enters the optical fiber low noise pre-amplifier, the subsequent signal preprocessing is performed to determine alignment.

The foregoing description is only illustrative of the present invention and is not intended to limit the scope of the invention, and all equivalent changes made by the specification and drawings of the present invention, or direct or indirect application in the relevant art, are included in the scope of the present invention.

Claims (9)

1. A free-space light-emitting-receiving module, comprising:

a laser emission module (100) for emitting a laser signal;

an optical circulator (200) comprising a first port (201), a second port (202) and a third port (203), wherein the first port (201) is used for receiving a laser signal emitted by a laser emitting module (100);

A micro lens (300) arranged at a second port (202) of the optical circulator (200) and used for receiving a laser signal output from the first port (201) into the second port (202) and transmitting the laser signal to the outside, and/or used for receiving an external laser signal and outputting the external laser signal from a third port (203) after inputting the external laser signal into the second port (202), wherein the micro lens (300) is provided with micro displacement drivers of two degrees of freedom of an X axis and a Y axis or micro displacement drivers of three degrees of freedom of the X axis, the Y axis and the Z axis;

And a laser receiving module (400) provided at the third port (203) of the optical circulator (200) for receiving the laser signal inputted from the second port (202).

2. The free-space light emitting and receiving module as set forth in claim 1, wherein the laser emitting module (100) comprises an emitting optical fiber (110), and a micro-displacement driver with two degrees of freedom of an X axis and a Y axis is arranged on the end of the emitting optical fiber (110).

3. The free-space light emitting and receiving module as set forth in claim 1, wherein the laser receiving module (400) comprises a receiving fiber (410), and a micro-displacement driver with two degrees of freedom of X-axis and Y-axis is disposed on the end of the receiving fiber (410).

4. The free-space light emitting and receiving module according to claim 1, wherein the light circulator (200) comprises a first polarization splitting prism (210), an optical rotation sheet (220) and a second polarization splitting prism (230) which are arranged along the light path direction, and a light filter (240) is arranged on one side of the first polarization splitting prism (210) opposite to the third port (203).

5. The free-space optical transmit-receive module as claimed in claim 1, characterized in that a power amplifying module (120) is arranged between the laser transmit-ing module (100) and the optical circulator (200).

6. The free-space optical transmit receive module as set forth in claim 1, wherein a low-noise pre-optical amplifier (420) is disposed between the laser receive module (400) and the optical circulator (200).

7. The free-space light emitting and receiving module as set forth in claim 1, wherein the micro-displacement driver is driven by a piezoelectric ceramic or a piezoelectric motor.

8. The free-space light emitting and receiving module as set forth in claim 1, wherein the exit end of the micro-lens (300) is provided with an auto-collimation lens (500') or a beam expander (500).

9. The free-space light emitting and receiving module as set forth in claim 1, wherein the laser emitting module (100) and the laser receiving module (400) are provided with a first collimating lens (101) therein.