CN116404505A - optical fiber amplifier - Google Patents

Abstract

The embodiment of the application discloses an optical fiber amplifier, this optical fiber amplifier includes: the device comprises an isolation module, an amplifying module and an output module, wherein the isolation module is provided with an input end and a first polarization maintaining optical fiber, the input end of the isolation module is used for being connected with a seed source, and the isolation module is used for transmitting a light beam generated by the seed source; the amplifying module is provided with a second polarization maintaining optical fiber and a third polarization maintaining optical fiber, the first polarization maintaining optical fiber is connected with the second polarization maintaining optical fiber in a first connection mode, the amplifying module is used for amplifying the light beam output by the isolation module, and the first connection mode is used for reducing the polarization degree of the light beam output by the isolation module; the output module is provided with a fourth polarization maintaining optical fiber, the third polarization maintaining optical fiber is connected with the fourth polarization maintaining optical fiber in a second connection mode, the output module is used for outputting the light beam amplified by the amplifying module, and the second connection mode is used for maintaining the polarization degree of the light beam amplified by the amplifying module. By adopting the technical scheme, the problems of lower output power lifting efficiency and the like of the laser are solved.

Description

optical fiber amplifier

technical field

This application relates to the field of lasers, in particular, to an optical fiber amplifier.

Background technique

Spectrum synthesis based on multiple high-power narrow-linewidth fiber lasers is an important way to realize 10,000-watt-class fiber lasers. However, when the narrow-linewidth fiber laser is amplified and transmitted in the fiber, it is easy to produce nonlinear effects, which leads to laser performance parameters. decrease while limiting the laser power boost.

In the prior art, the linearly polarized laser of the seed source based on single-frequency laser plus phase modulation technology can keep the spectral linewidth unchanged due to its time-domain stability after amplification, and has a high stimulated Brillouin Scattering and stimulated Raman scattering thresholds are therefore widely used in high-power narrow-linewidth fiber lasers. In this way, since the seed laser is a linearly polarized laser, even if a non-polarization-maintaining amplifier is used, there will be a certain depolarization effect, but due to the polarization gain correlation effect, the output laser polarization degree is still high, which will reduce the excited Bri Deep threshold, thereby limiting the power boost of narrow linewidth fiber lasers.

Aiming at the problems in the related art, such as the low efficiency of increasing the output power of the laser, no effective solution has been proposed yet.

Contents of the invention

An embodiment of the present application provides an optical fiber amplifier, so as to at least solve the problems in the related art, such as low efficiency of boosting the output power of a laser.

According to an embodiment of the embodiment of the present application, a fiber amplifier is provided, including: an isolation module, an amplification module and an output module, wherein,

The isolation module has an input end and a first polarization-maintaining optical fiber, the input end of the isolation module is used to connect to the seed source, and the isolation module is used to transmit the light beam generated by the seed source;

The amplifying module has a second polarization-maintaining optical fiber and a third polarization-maintaining optical fiber, the first polarization-maintaining optical fiber is connected to the second polarization-maintaining optical fiber in a first connection manner, and the amplifying module is used to amplify the polarization-maintaining optical fiber The light beam output by the isolation module, the first connection mode is used to reduce the degree of polarization of the light beam output by the isolation module;

The output module has a fourth polarization-maintaining optical fiber, the third polarization-maintaining optical fiber is connected to the fourth polarization-maintaining optical fiber by a second connection mode, and the output module is used to output the beam amplified by the amplification module , the second connection mode is used to maintain the degree of polarization of the light beam amplified by the amplification module.

Optionally, the first connection method includes forming a target angle between the polarization axis of the first polarization-maintaining fiber and the polarization axis of the second polarization-maintaining fiber, wherein the polarization axis of the fiber is used to indicate the polarization axis of the polarization-maintaining fiber direction of polarization.

Optionally, the target angle is determined according to the reduction amount of the polarization degree of the light beam output by the isolation module.

Optionally, the target angle is an angle falling within a target angle range, and the target angle range is [45°±n°], where n is a preset angle error.

Optionally, the target angle is 45°.

Optionally, the second connection method includes that the polarization axis of the third polarization-maintaining fiber and the polarization axis of the fourth polarization-maintaining fiber are on the same straight line, wherein the polarization axis of the fiber is used to indicate the polarization axis of the polarization-maintaining fiber polarization direction.

Optionally, the first polarization-maintaining fiber, the second polarization-maintaining fiber, the third polarization-maintaining fiber and the fourth polarization-maintaining fiber are all highly birefringent polarization-maintaining fibers.

Optionally, the isolation module further includes: a light guide end, wherein,

The light guide end is connected to the detection device;

The light guide end is used to output the isolated reverse return light to the detection device;

The detection device is used to detect the intensity of stimulated Brillouin scattered light in the return light spectrum of the reverse return light.

Optionally, the amplifying module includes: a first cladding optical filter, a gain fiber, a pump/signal coupler, a pump source group, and a second cladding optical filter, wherein,

The first polarization-maintaining fiber is connected to the second polarization-maintaining fiber at the input end of the first cladding optical filter, and the output end of the first cladding optical filter is connected to one end of the gain fiber connected, the other end of the gain fiber is connected to the first input end of the pump/signal coupler, the pumping source group is connected to the second input end of the pump/signal coupler, and the pump The output end of the pump/signal coupler is connected to the input end of the second cladding optical filter, and the output end of the second cladding optical filter is connected to the input end of the output module;

The second cladding optical filter is directly processed on the output fiber of the pump/signal coupler.

Optionally, the length of the output optical fiber of the pump/signal coupler is less than 20 cm.

In the embodiment of the present application, the optical fiber amplifier includes: an isolation module, an amplification module and an output module, wherein the isolation module has an input end and a first polarization-maintaining optical fiber, the input end of the isolation module is used to connect with the seed source, and the isolation module It is used to transmit the light beam generated by the seed source; the amplification module has a second polarization-maintaining fiber and a third polarization-maintaining fiber, the first connection between the first polarization-maintaining fiber and the second polarization-maintaining fiber is used, and the amplification module is used to amplify For the light beam output by the isolation module, the first connection mode is used to reduce the degree of polarization of the light beam output by the isolation module; the output module has a fourth polarization-maintaining optical fiber, and a second connection is adopted between the third polarization-maintaining optical fiber and the fourth polarization-maintaining optical fiber The output module is used to output the beam amplified by the amplifier module, and the second connection mode is used to maintain the degree of polarization of the beam amplified by the amplifier module, that is, the polarization maintaining fiber is used to connect the isolation module, the amplifier module and the output module, and the isolation module and the amplifier The polarization-maintaining optical fiber between the modules is connected by the first connection method, which can reduce the polarization degree of the beam output by the isolation module, thereby producing a depolarization effect, reducing the polarization degree of the laser, and in the subsequent propagation and amplification process In the second connection mode, the polarization maintaining fiber is connected to maintain the degree of polarization. By adjusting the connection mode of the polarization maintaining fiber between the functional modules to control the degree of polarization of the beam, the stimulated Brillouin threshold of the laser can be effectively improved, thereby improving The output power of the laser. By adopting the above-mentioned technical solution, the problems in related technologies such as the low efficiency of increasing the output power of the laser are solved, and the technical effect of increasing the efficiency of increasing the output power of the laser is realized.

Description of drawings

The accompanying drawings, which are incorporated in the specification and constitute a part of the specification, show embodiments consistent with the application, and are used together with the description to explain the principle of the embodiment of the application.

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, In other words, other drawings can also be obtained from these drawings without paying creative labor.

Fig. 1 is a structural block diagram one of an optical fiber amplifier according to an embodiment of the present application;

2 is a schematic diagram of a polarization-maintaining optical fiber fusion splicing angle according to an embodiment of the present application;

Fig. 3 is a structural block diagram 2 of an optical fiber amplifier according to an embodiment of the present application;

FIG. 4 is a structural block diagram three of an optical fiber amplifier according to an embodiment of the present application;

FIG. 5 is a structural block diagram four of an optical fiber amplifier according to an embodiment of the present application;

Fig. 6 is a schematic diagram of an optical fiber amplifier according to an embodiment of the present application.

Detailed ways

In order to enable those skilled in the art to better understand the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described implementation Examples are only some of the embodiments of the present application, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the embodiments of this application.

It should be noted that the terms "first" and "second" in the description and claims of the embodiments of the present application and the above drawings are used to distinguish similar objects, and not necessarily used to describe a specific order or sequence order. It is to be understood that the data so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a sequence of steps or elements is not necessarily limited to the expressly listed instead, may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

In the embodiment of the present application, a fiber amplifier is provided. FIG. 1 is a block diagram of a fiber amplifier according to the embodiment of the present application. As shown in FIG. 1, the fiber amplifier includes: an isolation module 102, an amplification module 104 and output module 106, wherein,

The isolation module 102 has an input end 102-1 and a first polarization maintaining optical fiber 102-2, the input end 102-1 of the isolation module 102 is used for connecting with a seed source, and the isolation module 102 is used for transmitting the The light beam generated by the seed source;

The amplification module 104 has a second polarization-maintaining fiber 104-1 and a third polarization-maintaining fiber 104-2, and the first polarization-maintaining fiber 102-2 and the second polarization-maintaining fiber 104-1 are connected by a second A connection mode connection, the amplification module 104 is used to amplify the light beam output by the isolation module 102, and the first connection mode is used to reduce the polarization degree of the light beam output by the isolation module;

The output module 106 has a fourth polarization-maintaining optical fiber 106-1, the third polarization-maintaining optical fiber 104-2 is connected to the fourth polarization-maintaining optical fiber 106-1 using a second connection mode, and the output module 106 is used to output the light beam amplified by the amplification module 104 , and the second connection mode is used to maintain the degree of polarization of the light beam amplified by the amplification module 104 .

Through the above equipment, the isolation module, the amplification module and the output module are connected by a polarization-maintaining optical fiber, and the polarization-maintaining optical fiber between the isolation module and the amplification module is connected by the first connection method, which can reduce the output beam of the isolation module degree of polarization, thereby producing a depolarization effect that reduces the degree of polarization of the laser, and in the subsequent propagation and amplification process, the second connection method is used to connect the polarization-maintaining fiber to maintain the degree of polarization. By adjusting the polarization-maintaining fiber between the functional modules The connection method controls the polarization degree of the beam, which can effectively increase the stimulated Brillouin threshold of the laser, thereby increasing the output power of the laser. By adopting the above-mentioned technical solution, the problems in related technologies such as the low efficiency of increasing the output power of the laser are solved, and the technical effect of increasing the efficiency of increasing the output power of the laser is realized.

Optionally, in this embodiment, the fiber amplifier can be applied to laser devices, such as narrow-linewidth fiber lasers, but is not limited to.

Optionally, in this embodiment, the first connection between the first polarization-maintaining fiber and the second polarization-maintaining fiber is used to reduce the degree of polarization of the beam output by the isolation module. The first connection can be, but not It is limited to reduce the degree of polarization of the beam output by the isolation module through the control of the connection method and connection parameters. For example, it can control the selection of welding or connectors, and control the connection parameters used in the selected connection method, such as : Splice Angle, Splice Length, Splice Width, Connector Angle, Connector Length, etc.

In an exemplary embodiment, the first connection method includes forming a target angle between the main axis of polarization of the first polarization-maintaining fiber and the main axis of polarization of the second polarization-maintaining fiber, wherein the main axis of polarization of the fiber is used for Indicates the polarization direction of the polarization maintaining fiber.

Optionally, in this embodiment, the first polarization-maintaining fiber and the second polarization-maintaining fiber are connected in such a way that a target angle is formed between the polarization axes, so that the linear polarization working on a single polarization axis (fast axis/slow axis) The light is distributed on the fast axis and the slow axis, which produces a depolarization effect and reduces the polarization degree of the laser.

In an exemplary embodiment, the target angle is determined according to the reduction amount of the polarization degree of the light beam output by the isolation module.

Optionally, in this embodiment, the reduction amount of the polarization degree of the light beam output by the isolation module can be adjusted through the target angle, so as to adjust the polarization effect according to requirements.

In an exemplary embodiment, the target angle is an angle falling within a target angle range, and the target angle range is [45°±n°], where n is a preset angle error.

Optionally, in this embodiment, the preset angle error can be used but not limited to represent the accuracy of the target angle, and can be controlled but not limited to by controlling the angle error and controlling the angle range of the target angle to achieve flexible and practical Requirements, control the target angle within the target angle range.

In an exemplary embodiment, the target angle is 45°.

Optionally, in this embodiment, the polarization-maintaining fiber between the isolation module and the amplification module can be, but not limited to, welded at an angle of 45° between the main axis of polarization, so that the linearly polarized optical fiber working on a single polarization axis (fast axis/slow axis) The light is evenly distributed on the fast axis and the slow axis, resulting in a depolarization effect, the laser polarization degree is reduced to zero, and in the subsequent propagation and amplification process, the polarization degree remains unchanged, and the reduction of the laser polarization degree can effectively improve the excited Brillouin of the laser. Threshold, thereby increasing the output power of the laser, while ensuring the stable operation of the laser.

In an exemplary embodiment, the second connection method includes that the polarization principal axis of the third polarization-maintaining fiber and the polarization principal axis of the fourth polarization-maintaining fiber are located on the same straight line, wherein the polarization principal axis of the fiber is used to indicate The polarization direction of the polarization maintaining fiber.

Optionally, in this embodiment, other polarization-maintaining fibers in the optical fiber amplifier except the polarization-maintaining fiber between the output end of the isolation module and the input end of the amplification module adopt a polarization main axis angle of 0 ° welding.

Fig. 2 is a schematic diagram of a polarization-maintaining optical fiber fusion splicing angle according to an embodiment of the present application. The fast axes of the polarization-maintaining fibers are spliced at 45°, and the fast axes of the third and fourth polarization-maintaining fibers are spliced at 0°.

In an exemplary embodiment, the polarization-maintaining fibers (i.e., the first polarization-maintaining fiber, the second polarization-maintaining fiber, the third polarization-maintaining fiber and the fourth polarization-maintaining fiber) in the optical fiber amplifier are high birefringence polarization-maintaining fibers optical fiber.

Optionally, in this embodiment, the high-birefringence polarization-maintaining fiber may include, but is not limited to, Panda polarization-maintaining 25 μm core, 400 μm cladding polarization-maintaining fiber, Panda polarization-maintaining 20 μm core, 400 μm cladding fiber, and double Polarization maintaining fiber whose refractive index meets the refractive index threshold, etc.

Optionally, in this embodiment, the polarization-maintaining optical fibers in the optical fiber amplifier are all fused by a fiber fusion splicer.

In an exemplary embodiment, the isolation module further includes: a light guide end, wherein,

The light guide end is connected to the detection device;

The light guide end is used to output the isolated reverse return light to the detection device;

The detection device is used to detect the intensity of stimulated Brillouin scattered light in the return light spectrum of the reverse return light.

Optionally, in this embodiment, the isolation module may be used to connect to a detection device, and the detection device detects the intensity of stimulated Brillouin scattered light in the return light spectrum of the back return light. Therefore, the target angle can also be adjusted according to the detected stimulated Brillouin scattered light intensity.

Optionally, in this embodiment, the isolation module includes: an optical fiber isolator, wherein the output end of the optical fiber isolator is connected to the input end of the amplification module; the input end of the optical fiber isolator is used for connecting wires A polarized seed source, the light guide end of the optical fiber isolator is used to output the isolated reverse return light, and the seed source includes the linearly polarized seed source.

Optionally, in this embodiment, FIG. 3 is a structural block diagram 2 of an optical fiber amplifier according to an embodiment of the present application. As shown in FIG. The second polarization-maintaining fiber 104-1 of 104 is connected; the input end 102-1 of the fiber isolator 202 is used for connecting the linearly polarized seed source 204, and the light guide end 206 of the fiber isolator 202 is used for outputting the reverse return light isolated , the light guide end 206 is connected to the detection device 208 , and the seed source includes a linearly polarized seed source 204 .

Optionally, in this embodiment, the optical fiber isolator includes: a linearly polarized three-port circulator.

In an exemplary embodiment, the amplifying module includes: a first cladding optical filter, a gain fiber, a pump/signal coupler, a pump source group, and a second cladding optical filter, wherein the The first polarization-maintaining fiber is connected to the second polarization-maintaining fiber at the input end of the first cladding optical filter, and the output end of the first cladding optical filter is connected to one end of the gain fiber , the other end of the gain fiber is connected to the first input end of the pump/signal coupler, the pump source group is connected to the second input end of the pump/signal coupler, and the pump The output end of the signal coupler is connected to the input end of the second cladding optical filter, and the output end of the second cladding optical filter is connected to the input end of the output module; the second cladding optical filter is connected to the input end of the output module; A cladding optical filter is machined directly on the output fiber of the pump/signal coupler.

Optionally, in this embodiment, the pump/signal coupler and the second cladding optical filter are conjoined devices, and the second cladding optical filter is on the output fiber of the pumping/signal coupler The direct processing makes the connecting fiber between the pump/signal coupler and the second cladding optical filter have no fusion joint.

In an exemplary embodiment, the length of the output fiber of the pump/signal coupler is less than 20 cm.

Optionally, in this embodiment, the output fiber of the pump/signal coupler is used as the connecting fiber between the pump/signal coupler and the second cladding optical filter, and the length of the optical fiber is less than a certain target threshold (such as 20cm ), and the output fiber of the pump/signal coupler should be as short as possible.

Optionally, in this embodiment, the light guide end of the fiber isolator can be used, but not limited to, to output the isolated reverse return light, and monitor the intensity of stimulated Brillouin scattered light in the return light spectrum; the first package The layer optical filter can be but not limited to be used to filter the signal light and redundant pump light in the fiber cladding, the gain fiber can be but not limited to be used to convert the pump light into signal light, and then realize laser amplification; the pump The pump/signal coupler can be but not limited to be used to couple the pump light into the cladding of the gain fiber; the pump source group can be but not limited to provide pump light for the amplifier; the cladding optical filter can be but not limited to use To filter out cladding light, fiber end caps can be used but not limited to laser spatial output. The pump/signal coupler and the second cladding optical filter are conjoined components, and the intermediate optical fiber has no fusion point and the length is as short as possible.

Optionally, in this embodiment, FIG. 4 is a structural block diagram three of an optical fiber amplifier according to an embodiment of the present application. As shown in FIG. 4, the amplification module may include, but is not limited to: a cladding optical filter 302 ( That is, the above-mentioned first cladding optical filter), gain fiber 304, pump/signal coupler 306, pumping source group 308 and cladding optical filter 310 (that is, the above-mentioned second cladding optical filter ). The input end 102-1 of the fiber isolator 202 is connected with the linearly polarized seed source 204, and the first polarization-maintaining fiber 102-2 of the fiber isolator 202 is connected with the input end 302-1 of the cladding light filter 302, and the cladding light The output end 302-2 of the filter 302 is connected with one end 304-1 of the gain fiber 304, and the other end 304-2 of the gain fiber 304 is connected with the first input end 306-1 of the pump/signal coupler 306, and the pump The source group 308 is connected to the second input end 306-2 of the pump/signal coupler 306, and the output end 306-3 of the pump/signal coupler 306 is connected to the input end 310-1 of the cladding optical filter 310, The output end 310-2 of the cladding optical filter 310 is connected with the fourth polarization-maintaining optical fiber 106-1 of the output module 106; the pumping/signal coupler 306 and the cladding optical filter 310 are Siamese devices, and the pumping The connecting fiber between the /signal coupler 306 and the cladding optical filter 310 has no fusion point and the length of the connecting fiber is less than the target threshold.

In an exemplary embodiment, the output module includes a fiber optic end cap.

Optionally, in this embodiment, the fiber end cap can be, but not limited to, used for laser spatial output. FIG. 5 is a block diagram four of a fiber amplifier according to an embodiment of the present application. As shown in FIG. 5, the fiber isolator The input end 102-1 of 202 is connected with the linearly polarized seed source 204, and the first polarization-maintaining fiber 102-2 of the fiber isolator 202 is connected with the input end 302-1 of the cladding optical filter 302, and the cladding optical filter The output end 302-2 of 302 is connected with one end 304-1 of the gain fiber 304, and the other end 304-2 of the gain fiber 304 is connected with the first input end 306-1 of the pump/signal coupler 306, and the pump source group 308 It is connected with the second input end 306-2 of the pumping/signal coupler 306, and the output end 306-3 of the pumping/signal coupler 306 is connected with the input end 310-1 of the cladding light filter 310, and the cladding light The output end 310-2 of filter 310 is connected with the input end 402-1 of fiber end cap 402; The connecting fiber with the cladding optical filter 310 has no fusion splice and the length of the connecting fiber is less than the target threshold.

In order to better understand the above-mentioned fiber amplifier, the structure of the above-mentioned fiber amplifier will be described below in combination with optional embodiments, but it is not used to limit the technical solutions of the embodiments of the present application.

A fiber amplifier is provided in this embodiment. FIG. 6 is a schematic diagram of a fiber amplifier according to an embodiment of the present application. As shown in FIG. Optical filter 2 (i.e. the above-mentioned first cladding optical filter), gain fiber 3, pump/signal coupler 4, pumping source group 5, cladding optical filter 6 (i.e. the above-mentioned second cladding optical filter) and fiber end cap 7. Fiber isolator 1, cladding light filter 2, gain fiber 3, pump/signal coupler 4, input fiber of cladding light filter 6, output fiber and input fiber of fiber end cap 7 are high double Refractive polarization maintaining fiber. The fiber optic isolator 1 may, but is not limited to, include A1 end (that is, the input end of the above-mentioned fiber isolator), A2 end (that is, the light guide end of the above-mentioned fiber isolator) and A3 end (that is, the output end of the above-mentioned fiber isolator) ), the pumping/signal coupler 4 can but is not limited to include B1 end (ie the first input of the above-mentioned pumping/signal coupler), B2 end (ie the output end of the above-mentioned pumping/signal coupler), B3 end (that is, the second input end of the pump/signal coupler mentioned above). Lightpaths can be made, but not limited to, by:

The output end A3 of the optical fiber isolator 1 and the input end of the cladding optical filter 2 are welded at a polarization axis angle of 45°, except for the output end A3 of the optical fiber isolator 1 (that is, the output end of the above-mentioned optical fiber isolator) All other polarization-maintaining optical fibers other than the input end of the cladding optical filter 2 are welded at a polarization axis angle of 0°, and the pump end B3 of the pump/signal coupler 4 (i.e. the above-mentioned pump/signal The pump fiber at the second input end of the coupler and the pump fiber at the output end of the pump source group 5 are directly fused with the same kind of multimode fiber. The linearly polarized seed laser light emitted by the linearly polarized seed source 8 passes through the fiber isolator 1 to output the same linearly polarized laser light, and then passes through the fiber isolator 1 and the cladding light filter 2 to produce depolarization after the fusion point, and is maintained in the follow-up The polarization state is kept unchanged during the amplification and transmission process of the polarized fiber.

Optionally, in this embodiment, the input optical fiber, output optical fiber and The gain fiber 3 may be, but not limited to, adopt a Panda polarization-maintaining fiber with a core of 20 μm and a cladding fiber of 400 μm. The optical fiber isolator 1 adopts the fast axis working mode, and the input power along the fast axis is 50W, the wavelength is 1064nm narrow line width seed laser, and the polarization state of the signal light is close to zero after passing through the 45° fusion point of the optical fiber isolator 1 and the cladding optical filter 2 , and then amplified to 1500W by the gain fiber 3, the measured laser polarization degree remains unchanged, and there is no obvious stimulated Brillouin scattered light in the return light monitoring of the fiber isolator 1.

Optionally, in this embodiment, the output fiber and input fiber of the optical fiber isolator 1 can also be, but not limited to, adopt Panda polarization-maintaining 20 μm core, 400 μm cladding polarization-maintaining fiber, cladding optical filter 2, pump The input fiber, output fiber and gain fiber 3 of the pump/signal coupler 4, the cladding optical filter 6, and the fiber end cap 7 can, but are not limited to, adopt Panda polarization-maintaining 25 μm core and 400 μm cladding polarization-maintaining fiber. The optical fiber isolator 1 adopts the fast axis working mode, and the input power along the fast axis is 100W, the wavelength is 1050nm narrow line width seed laser, and the polarization state of the signal light is close to zero after passing through the 45° fusion point of the optical fiber isolator 1 and the cladding optical filter 2 , and then amplified to 1500W by the gain fiber 3, the measured laser polarization degree remains unchanged, and there is no obvious stimulated Brillouin scattered light in the return light monitoring of the fiber isolator 1.

Optionally, for specific examples in this embodiment, reference may be made to the examples described in the foregoing embodiments and optional implementation manners, and details are not repeated in this embodiment.

Obviously, those skilled in the art should understand that the modules or steps of the above-mentioned embodiments of the present application can be implemented by general-purpose computing devices, and they can be concentrated on a single computing device, or distributed among multiple computing devices. Optionally, they may be implemented in program code executable by a computing device, thereby, they may be stored in a storage device to be executed by a computing device, and in some cases, may be implemented in a code different from that described herein The steps shown or described are executed in sequence, or they are fabricated into individual integrated circuit modules, or multiple modules or steps among them are fabricated into a single integrated circuit module for implementation. Thus, embodiments of the present application are not limited to any specific combination of hardware and software.

The above descriptions are only preferred implementations of the embodiments of the present application. It should be pointed out that for those skilled in the art, some improvements and modifications can be made without departing from the principle of the embodiments of the present application. Improvements and modifications should also be regarded as the scope of protection of the embodiments of the present application.

Claims (10)

1. An optical fiber amplifier, comprising: the device comprises an isolation module, an amplifying module and an output module, wherein the isolation module is provided with an input end and a first polarization maintaining optical fiber, the input end of the isolation module is used for being connected with a seed source, and the isolation module is used for transmitting a light beam generated by the seed source;

the amplifying module is provided with a second polarization maintaining optical fiber and a third polarization maintaining optical fiber, the first polarization maintaining optical fiber is connected with the second polarization maintaining optical fiber in a first connection mode, the amplifying module is used for amplifying the light beam output by the isolation module, and the first connection mode is used for reducing the polarization degree of the light beam output by the isolation module;

the output module is provided with a fourth polarization maintaining optical fiber, the third polarization maintaining optical fiber is connected with the fourth polarization maintaining optical fiber in a second connection mode, the output module is used for outputting the light beam amplified by the amplifying module, and the second connection mode is used for keeping the polarization degree of the light beam amplified by the amplifying module.

2. The fiber amplifier of claim 1, wherein the first connection means comprises a target angle formed between a principal axis of polarization of the first polarization maintaining fiber and a principal axis of polarization of the second polarization maintaining fiber, wherein the principal axes of polarization of the fibers are used to indicate a polarization direction of the polarization maintaining fibers.

3. The fiber amplifier of claim 2, wherein the target angle is determined based on an amount of reduction in the polarization degree of the beam output by the isolation module.

4. The fiber amplifier of claim 2, wherein the target angle is an angle that falls within a target angle range of [45 ° ± n ° ], wherein n is a preset angle error.

5. The fiber amplifier of claim 2, wherein the target angle is 45 °.

6. The fiber amplifier of claim 1, wherein the second connection means comprises a principal axis of polarization of the third polarization maintaining fiber being co-linear with a principal axis of polarization of the fourth polarization maintaining fiber, wherein the principal axis of polarization of the fiber is used to indicate the polarization direction of the polarization maintaining fiber.

7. The fiber amplifier of claim 1, wherein the first polarization maintaining fiber, the second polarization maintaining fiber, the third polarization maintaining fiber and the fourth polarization maintaining fiber are both high-birefringence polarization maintaining fibers.

8. The fiber amplifier of claim 1, wherein the isolation module further comprises: a light guide end, wherein,

the light guide end is connected with the detection device;

the light guide end is used for outputting isolated reverse return light to the detection device;

the detection device is used for detecting the intensity of the stimulated Brillouin scattering light in the return light spectrum of the reverse return light.

9. The fiber amplifier of claim 1, wherein the amplification module comprises: the first cladding light filter, the gain fiber, the pump/signal coupler, the pump source group and the second cladding light filter, wherein,

the first polarization maintaining fiber is connected with the second polarization maintaining fiber at the input end of the first cladding light filter, the output end of the first cladding light filter is connected with one end of the gain fiber, the other end of the gain fiber is connected with the first input end of the pump/signal coupler, the pump source group is connected with the second input end of the pump/signal coupler, the output end of the pump/signal coupler is connected with the input end of the second cladding light filter, and the output end of the second cladding light filter is connected with the input end of the output module;

the second cladding optical filter is directly machined on the output fiber of the pump/signal coupler.

10. The fiber amplifier of claim 9, wherein the length of the output fiber of the pump/signal coupler is less than 20cm.

Images