A coaxial transceiver compact laser transceiver device

Abstract

The present invention belongs to the technical field of laser transceiver devices, and discloses a coaxial and compact laser transceiver device, which includes an optical lens, a coupling component, a multimode transceiver optical fiber, a retroreflection dissipator, and a multimode fiber circulator; the multimode fiber circulator includes three ports, the first port serves as the transmitting end, the third port serves as the receiving end, and the second port is connected to one end of the retroreflection dissipator; the other end of the retroreflection dissipator is connected to the multimode transceiver optical fiber; the coupling component is arranged in the optical path between the multimode transceiver optical fiber and the optical lens. The present invention solves the problems in the prior art that the laser coaxial alignment and adjustment of the laser transceiver device are complex, and the isolation degree between the transmitting port and the receiving port of the multimode fiber circulator is relatively low. The present invention can realize high-isolation laser coaxial transceiver and reduce the volume of the device.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser transceiver devices, and more specifically, relates to a coaxial and compact laser transceiver device for both transmitting and receiving. Background Art

[0002] In a conventional laser device, the alignment process of laser coaxiality is complex, and the reliability and stability of transmitting and receiving laser are poor. The biggest feature of an optical fiber circulator is that it can use the same optical fiber to complete signal transmission and reception, but it is usually used in optical fiber lines and rarely used in free-space optical paths. If an optical fiber circulator is applied to a free-space optical path, the following problems will occur: when the transmitted signal enters the atmospheric medium from the optical fiber medium at port 2 of the optical fiber circulator, due to the sudden change in the refractive index of the medium, the atmospheric medium will reflect part of the signal back into the optical fiber medium and reach port 3 of the optical fiber circulator, forming crosstalk and causing the isolation between port 1 and port 3 of the optical fiber circulator to decrease. For a single-mode optical fiber circulator, the crosstalk between port 1 and port 3 caused by this atmospheric reflection is relatively small, and the isolation is about -40 dB, which can still be used for short-distance and low-power laser transmission, but it cannot be used in scenarios where the isolation requirement is greater than 40 dB. For a multi-mode optical fiber circulator, since the core diameter of the multi-mode optical fiber is 5 - 7 times larger than that of the single-mode optical fiber and the area is 30 - 47 times larger, if a multi-mode optical fiber circulator is used, the signal intensity of the transmitted signal reflected by the atmospheric medium back into the optical fiber medium will increase a lot, resulting in the isolation between port 1 and port 3 being only about -15 dB. Therefore, multi-mode optical fiber circulators cannot be applied to existing free-space laser transceiver systems. Summary of the Invention

[0003] The present invention provides a coaxial and compact laser transceiver device for both transmitting and receiving, which solves the problems in the prior art that the laser coaxial alignment of the laser transceiver device is complex and the isolation between the transmitting port and the receiving port of the multi-mode optical fiber circulator is low.

[0004] The present invention provides a coaxial and compact laser transceiver device for both transmitting and receiving, including: an optical lens, a coupling component, a multi-mode transmitting and receiving optical fiber, a retro-reflection dissipator, and a multi-mode optical fiber circulator;

[0005] The multi-mode optical fiber circulator includes three ports. The first port serves as the transmitting end, the third port serves as the receiving end, and the second port is connected to one end of the retro-reflection dissipator; the other end of the retro-reflection dissipator is connected to the multi-mode transmitting and receiving optical fiber; the coupling component is arranged in the optical path between the multi-mode transmitting and receiving optical fiber and the optical lens;

[0006] The signal laser emitted by the signal laser of the other party is received and converged by the optical lens, then reflected by the coupling component to the end face of the multimode transceiver fiber and propagates into the fiber. Then, the optical signal enters the second port of the multimode fiber circulator after passing through the retroreflection dissipator, and finally reaches the third port of the multimode fiber circulator and is received by the detector.

[0007] The signal laser emitted by the signal laser of this party enters through the first port of the multimode fiber circulator, and successively passes through the second port of the multimode fiber circulator, the retroreflection dissipator, the multimode transceiver fiber, the coupling component, and the optical lens, and then is emitted to the other party.

[0008] Preferably, the coaxial compact laser transceiver device further includes: a camera and a beacon laser; the beacon laser is used to emit beacon laser, and the camera and the beacon laser are used to achieve optical path alignment.

[0009] Preferably, the retroreflection dissipator includes: a first multimode fiber, a second multimode fiber, a third multimode fiber, a first flange, and a second flange;

[0010] The first flange is used to connect the first multimode fiber and the second multimode fiber, and the second flange is used to connect the second multimode fiber and the third multimode fiber; the end faces of the first multimode fiber, the second multimode fiber, and the third multimode fiber all adopt an APC structure.

[0011] Preferably, a matching paste with the same refractive index as the refractive index of the fiber core is applied at the joint between the first multimode fiber and the second multimode fiber, and a matching paste with the same refractive index as the refractive index of the fiber core is applied at the joint between the second multimode fiber and the third multimode fiber.

[0012] Preferably, the coupling component includes: a first mirror and a second mirror;

[0013] The first mirror and the second mirror are used to reflect the converged light beam received by the optical lens to the center of the end face of the multimode transceiver fiber, and to reflect the light beam output by the multimode transceiver fiber to the optical lens and emit it.

[0014] Preferably, the coupling component includes: a first mirror, a galvanometer, a beam splitter, a quadrant detector, a signal processing circuit, a single-chip microcomputer control board, and a galvanometer drive circuit;

[0015] The signal laser emitted by the signal laser of the other party and the beacon laser emitted by the beacon laser of the other party form convergent light after being received by the optical lens. The convergent light is reflected by the first mirror to the mirror surface of the galvanometer, and then reflected by the mirror surface to the beam splitter. The signal laser passes through the beam splitter and is incident on the center of the end face of the multimode transceiver fiber and coupled into the fiber. The beacon laser is reflected by the beam splitter and incident on the quadrant detector. The quadrant detector converts the optical signal into an electrical signal and inputs it to the signal processing circuit. The signal processing circuit outputs four electrical signals to the single-chip microcomputer control board. The single-chip microcomputer control board analyzes and processes the four electrical signals to obtain the spot position parameters, and then sends the spot position parameters to the galvanometer drive circuit. The galvanometer drive circuit uses the spot position parameters as feedback signals and controls the deflection of the mirror surface of the galvanometer to align the signal laser with the center of the end face of the multimode transceiver fiber.

[0016] Preferably, the camera is a CMOS camera.

[0017] Preferably, the galvanometer is a voice coil motor type galvanometer.

[0018] Preferably, the wavelength of the signal laser is in the 1064nm or 1550nm band.

[0019] Preferably, the wavelength of the beacon laser is in the 800nm band.

[0020] One or more technical solutions provided in the present invention have at least the following technical effects or advantages:

[0021] In the invention, a retroreflection dissipator is connected to the second port of the multimode fiber circulator, which can effectively improve the isolation between the transmitting port and the receiving port of the multimode fiber circulator. The use of a multimode fiber circulator can achieve coaxial laser transceiver and sharing a single fiber for transceiver, eliminating the complex alignment process of laser coaxiality in conventional laser devices, and can greatly improve the reliability and stability of the transceiver laser. The folded optical path is realized through the coupling component, which can effectively reduce the mechanism size and achieve a compact structure. The present invention can achieve high-isolation coaxial laser transceiver and reduce the device volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of a coaxial and compact laser transceiver device provided in Embodiment 1 of the present invention;

[0023] Figure 2 It is a schematic structural diagram of the retroreflection dissipator;

[0024] Figure 3 It is a schematic structural diagram of a coaxial and compact laser transceiver device provided in Embodiment 2 of the present invention.

[0025] Among them, 1 - optical lens, 2 - camera, 3 - beacon laser, 4 - first mirror, 5 - second mirror, 6 - multimode transceiver fiber, 7 - retro - reflection dissipator, 8 - multimode fiber circulator, 9 - galvanometer, 10 - beam splitter, 11 - single - chip microcomputer control board, 12 - quadrant detector, 13 - signal processing circuit, 14 - galvanometer drive circuit. Specific embodiments

[0026] In order to better understand the above - mentioned technical solution, the above - mentioned technical solution will be described in detail below in conjunction with the accompanying drawings of the specification and specific embodiments.

[0027] The present invention provides a co -axial and compact laser transceiver device. Refer to Figure 1 , which mainly includes: an optical lens 1, a coupling component, a multimode transceiver fiber 6, a retro - reflection dissipator 7, and a multimode fiber circulator 8.

[0028] The multimode fiber circulator 8 includes three ports. The first port serves as the transmitting end, the third port serves as the receiving end, and the second port is connected to one end of the retro - reflection dissipator 7; the other end of the retro - reflection dissipator 7 is connected to the multimode transceiver fiber 6; the coupling component is arranged in the optical path between the multimode transceiver fiber 6 and the optical lens 1.

[0029] The signal laser emitted by the signal laser of the other party is received and converged by the optical lens 1, then reflected by the coupling component to the end face of the multimode transceiver fiber 6 and coupled into the fiber for transmission. This optical signal enters the second port of the multimode fiber circulator 8 after passing through the retro - reflection dissipator 7 and finally reaches the third port of the multimode fiber circulator 8 to be received by the detector.

[0030] The signal laser emitted by the signal laser of this party enters through the first port of the multimode fiber circulator 8, and successively passes through the second port of the multimode fiber circulator 8, the retro - reflection dissipator 7, the multimode transceiver fiber 6, the coupling component, and the optical lens 1 and then is emitted to the other party.

[0031] The present invention uses a multimode fiber circulator and a retro - reflection dissipator to realize the sharing of a single multimode fiber for laser emission and laser reception. The multimode transceiver fiber is the entrance and exit for emitting and receiving lasers, and is a shared fiber for transceiver, realizing high - isolation co -axial laser transceiver.

[0032] In addition, it may further include a camera 2 and a beacon laser 3; the beacon laser 3 is used to emit beacon laser with a slightly larger divergence angle, and the camera 2 and the beacon laser 3 are used to achieve optical path alignment.

[0033] Refer to Figure 1 , the transmitting port of the multimode fiber circulator 8 (i.e.,Figure 1 The 01 port in it) is connected to a signal laser, and the receiving port of the multimode fiber circulator 8 (i.e., Figure 1 The 03 port in it) is connected to a detector. The working process of the multimode fiber circulator 8 is as follows: The transmitted signal is injected from the 01 port and transmitted out through the 02 port (i.e., the second port). The received signal enters the optical fiber from the 02 port and finally reaches the 03 port, but will not reach the 01 port. It realizes that both the transmitted and received signals enter and exit from the 02 port, achieving the sharing of the optical fiber for transmission and reception, that is, realizing the coaxial function of signal transmission and reception, and solving the difficulty of coaxial alignment of signal transmission and reception in the conventional transmission and reception structure. To solve the problem of too low isolation degree of the multimode fiber circulator in space laser transmission applications, the present invention proposes a solution of connecting a retroreflection dissipator 7 to the 02 port of the multimode fiber circulator 8. After the multimode fiber circulator 8 is connected to the retroreflection dissipator 7, the isolation degree between the 01 port and the 03 port can be greater than 45 dB, and it can be applied to many space laser transceiver devices.

[0034] In specific applications, the wavelength of the signal laser is in the 1064 nm or 1550 nm band. The wavelength of the beacon laser 3 is in the 800 nm band, and the camera 2 uses a CMOS camera. The CMOS camera can see near-infrared laser, and both are used for target alignment.

[0035] Among them, as Figure 2 shown, the retroreflection dissipator 7 includes: a first multimode optical fiber (i.e., Figure 2 the multimode optical fiber 1 in it), a second multimode optical fiber (i.e., Figure 2 the multimode optical fiber 2 in it), a third multimode optical fiber (i.e., Figure 2 the multimode optical fiber 3 in it), a first flange (i.e., Figure 2 the flange 1 in it) and a second flange (i.e., Figure 2The flange in (2); the first flange is used to connect the first multimode optical fiber and the second multimode optical fiber, and the second flange is used to connect the second multimode optical fiber and the third multimode optical fiber; the end faces of the first multimode optical fiber, the second multimode optical fiber, and the third multimode optical fiber all adopt the APC structure. Aiming at the problem that laser transmission is prone to generate reflected light returning into the optical fiber in the medium mutation region, the end face of the optical fiber adopts the APC structure, that is, the end face is not flat but has an 8-degree bevel structure, which can greatly reduce the reflected light returning into the optical fiber. In addition, a matching paste with the same refractive index as the refractive index of the optical fiber core is applied at the joint of the first multimode optical fiber and the second multimode optical fiber, and a matching paste with the same refractive index as the refractive index of the optical fiber core is applied at the joint of the second multimode optical fiber and the third multimode optical fiber. By applying a matching paste with the same refractive index as the refractive index of the optical fiber core at the joints of two APC optical fibers, the medium mutation region at the optical fiber joints can be eliminated, the phenomenon of reflected light can be greatly reduced, the high isolation between the transmitting port and the receiving port of the multimode optical fiber circulator can be realized, the space laser emission and laser reception can share a multimode optical fiber, and the laser coaxial transceiver can be realized.

[0036] On the basis of the above solution, two specific embodiments are provided to further illustrate the present invention.

[0037] Embodiment 1:

[0038] A coaxial transceiver compact laser transceiver device provided in Embodiment 1, see Figure 1 , the coupling component includes: a first mirror 4 and a second mirror 5. The first mirror 4 and the second mirror 5 are used to reflect the converging light beam received by the optical lens 1 to the center of the end face of the multimode transceiver optical fiber 6, and to reflect the light beam output by the multimode transceiver optical fiber 6 to the optical lens 1 and emit it.

[0039] In Embodiment 1, by placing the first mirror 4 and the second mirror 5 in the receiving optical path of the optical lens, the incident converging light is folded back to the center of the end face of the multimode transceiver optical fiber 6, and thus coupled into the optical fiber and transmitted to the detector located at the third port of the multimode optical fiber circulator 8. Such an optical path design can reduce the size and volume of the system and achieve a compact structure.

[0040] Embodiment 2:

[0041] Long-distance laser atmospheric transmission will be affected by atmospheric turbulence, which will cause the jitter of the received light spot and the fluctuation of the light intensity, resulting in unstable received signals. Embodiment 2 adds a beam stabilizer to the structure to achieve the function of stabilizing the received light spot.

[0042] A coaxial transceiver compact laser transceiver device provided in Embodiment 2, see Figure 3, the coupling component includes: a first mirror 4, a galvanometer 9, a beam splitter 10, a quadrant detector 12, a signal processing circuit 13, a single-chip microcomputer control board 11, and a galvanometer driving circuit 14. It can be understood that the beam stabilizer includes a beam splitter 10, a quadrant detector 12, a signal processing circuit 13, a single-chip microcomputer control board 11, a galvanometer 9, and a galvanometer driving circuit 14.

[0043] The signal laser emitted by the signal laser of the other party and the beacon laser emitted by the beacon laser of the other party form a converging light after being received by the optical lens 1. This converging light (including the signal laser and the beacon laser) is reflected by the first mirror 4 to the mirror surface of the galvanometer 9. The galvanometer 9 reflects the signal laser and the beacon laser to the beam splitter 10. The signal laser is transmitted through the beam splitter 10 and then incident on the center of the end face of the multimode transceiver fiber 6 and coupled into the fiber. The beacon laser is reflected by the beam splitter 10 and then incident on the quadrant detector 12. The quadrant detector 12 converts the optical signal into an electrical signal and inputs it to the signal processing circuit 13. The signal processing circuit 13 outputs four electrical signals to the single-chip microcomputer control board 11. The single-chip microcomputer control board 11 analyzes and processes the four electrical signals to obtain the spot position parameters, and then sends the spot position parameters to the galvanometer driving circuit 14. The galvanometer driving circuit 14 uses the spot position parameters as feedback signals to control the mirror surface of the galvanometer 9 to deflect so that the signal laser is aligned with the center of the end face of the multimode transceiver fiber 6. The received light enters the third port of the multimode fiber circulator 8 through the retroreflector 7 and is received by the receiving detector, completing the reception and detection of the laser.

[0044] Specifically, the signal processing circuit 13 outputs four optical currents with corresponding intensities according to the light intensities irradiated in different quadrants, which is equivalent to outputting the position of the spot on the quadrant detector 12. The four optical currents are processed by the single-chip microcomputer control board 11 to obtain the spot position (coordinate) parameters. The galvanometer driving circuit 14 uses this parameter as a feedback signal to control the galvanometer 9 to make an appropriate angular deflection.

[0045] Embodiment 2 can realize the automatic tracking of the laser through a galvanometer and a quadrant detector.

[0046] Galvanometers can be divided into piezoelectric ceramic type, voice coil motor type, and mechanical rotating mirror type, each with its own advantages and disadvantages. The galvanometer in the present invention adopts a voice coil motor type galvanometer, which has the characteristics of a large swing angle range and a lower cost than piezoelectric ceramics.

[0047] The technical effects of a coaxial and compact laser transceiver device provided by an embodiment of the present invention at least include the following:

[0048] (1) The multi-mode fiber optic circulator adopted by the present invention can achieve coaxial laser transceiver and sharing the same optical fiber for transceiver, eliminating the complex alignment process of laser coaxiality in conventional laser devices, and greatly improving the reliability and stability of the transceiver laser.

[0049] (2) The present invention connects a backlight dissipator to the second port of the multi-mode fiber optic circulator, which can effectively improve the isolation degree between the transmitting port and the receiving port of the multi-mode fiber optic circulator.

[0050] (3) The present invention realizes the return optical path through the coupling component, which can effectively reduce the mechanism size and achieve a compact structure.

[0051] (4) Since the multi-mode fiber core diameter is 5-7 times larger than the single-mode fiber core diameter and the area is 30-47 times larger, the received optical power using the multi-mode fiber optic circulator is 30-47 times larger than that using the single-mode fiber optic circulator, greatly improving the laser receiving efficiency and stability.

[0052] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A coaxial transceiver compact laser transceiver device, characterized in that, Comprising: An optical lens, a coupling component, a multimode transceiver fiber, a backward light dissipator, and a multimode fiber circulator; The coupling component includes a first mirror and a second mirror; the first mirror and the second mirror are used to reflect the converging light beam received by the optical lens to the center of the end face of the multimode transceiver fiber, and to reflect the light beam output by the multimode transceiver fiber to the optical lens for emission; The backward light dissipator includes: a first multimode fiber, a second multimode fiber, a third multimode fiber, a first flange, and a second flange; the first flange is used to connect the first multimode fiber and the second multimode fiber, and the second flange is used to connect the second multimode fiber and the third multimode fiber; the end faces of the first multimode fiber, the second multimode fiber, and the third multimode fiber all adopt an APC structure; a matching paste with the same refractive index as the refractive index of the fiber core is applied at the joint between the first multimode fiber and the second multimode fiber, and a matching paste with the same refractive index as the refractive index of the fiber core is applied at the joint between the second multimode fiber and the third multimode fiber; The multimode fiber circulator includes three ports, the first port serves as the transmitting end, the third port serves as the receiving end, and the second port is connected to one end of the backward light dissipator; the other end of the backward light dissipator is connected to the multimode transceiver fiber; the coupling component is arranged in the optical path between the multimode transceiver fiber and the optical lens; The signal laser emitted by the signal laser of the other party is received and converged by the optical lens, reflected by the coupling component to the end face of the multimode transceiver fiber and propagated into the fiber, then the signal laser enters the second port of the multimode fiber circulator after passing through the backward light dissipator, and finally reaches the third port of the multimode fiber circulator to be received by the detector; The signal laser emitted by the signal laser of this party enters through the first port of the multimode fiber circulator, and is sequentially emitted to the other party after passing through the second port of the multimode fiber circulator, the backward light dissipator, the multimode transceiver fiber, the coupling component, and the optical lens.

2. The coaxial transceiver compact laser transceiver device according to claim 1, wherein, Further comprising: A camera and a beacon laser; The beacon laser is used to emit beacon laser, and the camera and the beacon laser are used to achieve optical path alignment.

3. The coaxial transceiver compact laser transceiver device according to claim 2, characterized in that, The coupling component includes: a first mirror, a galvanometer, a beam splitter, a quadrant detector, a signal processing circuit, a single-chip microcomputer control board, and a galvanometer drive circuit; The signal laser emitted by the signal laser of the other party and the beacon laser emitted by the beacon laser of the other party form a converging light after being received by the optical lens. The converging light is reflected by the first mirror to the mirror surface of the galvanometer, and then reflected by the mirror surface to the beam splitter. The signal laser passes through the beam splitter and is incident on the center of the end face of the multimode transceiver fiber and coupled into the fiber. The beacon laser is incident on the quadrant detector after being reflected by the beam splitter. The quadrant detector converts the optical signal into an electrical signal and inputs it to the signal processing circuit. The signal processing circuit outputs four electrical signals to the single-chip microcomputer control board. The single-chip microcomputer control board analyzes and processes the four electrical signals to obtain the spot position parameters, and then sends the spot position parameters to the galvanometer drive circuit. The galvanometer drive circuit uses the spot position parameters as feedback signals to control the deflection of the mirror surface of the galvanometer so that the signal laser is aligned with the center of the end face of the multimode transceiver fiber.

4. The coaxial transceiver compact laser transceiver device according to claim 2, characterized in that The camera uses a CMOS camera.

5. The coaxial transceiver compact laser transceiver device according to claim 3, characterized in that The galvanometer uses a voice coil motor type galvanometer.

6. The coaxial transceiver compact laser transceiver device according to claim 1, characterized in that The wavelength of the signal laser is in the 1064nm or 1550nm band.

7. The coaxial transceiver compact laser transceiver device according to claim 2, characterized in that The wavelength of the beacon laser is in the 800nm band.

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