Evaluation method and system for characterizing the anti-return light capability of semiconductor lasers

Abstract

The present invention provides an evaluation method and system for characterizing the anti-back reflection ability of a semiconductor laser. By constructing a measurement optical path, the power P of the laser with a wavelength range from λ1 to λ2 entering the semiconductor laser to be characterized is measured. i And the power P of the laser output by the semiconductor laser to be characterized after being absorbed by the doped optical fiber. o And the spectrum I(λ). Based on the remaining ratio a, the power P i , the power P o And the spectrum I(λ), the average amplification factor F is calculated; based on the magnitude of the average amplification factor F, the strength of the anti-back reflection ability of the semiconductor laser is evaluated. The evaluation method provided by the present invention has universality and can evaluate the anti-back reflection ability of different types of semiconductor lasers under different working conditions for lasers with different wavelength ranges and different powers.

Description

Technical Field

[0001] The invention mainly relates to the technical field of high-power lasers, in particular to an evaluation method and system for characterizing the anti-return light capability of semiconductor lasers. Background Art

[0002] As an important pump laser, semiconductor lasers are widely used in different types of high-power laser systems. In high-power laser systems pumped by semiconductor lasers, it is inevitable that lasers of other wavelengths will enter the semiconductor laser. When the laser entering the semiconductor laser is within the gain spectrum of the semiconductor laser and is amplified by the semiconductor laser, this may cause a significant decrease in the purity of the semiconductor laser output spectrum, thereby causing serious degradation of the performance of the entire high-power laser system. In order to ensure the stable operation of high-power laser systems pumped by semiconductor lasers, it is necessary to test and evaluate the anti-return light ability of semiconductor lasers. However, in the prior art, there has been no public report on relevant technical solutions for testing and evaluating the anti-return light ability of semiconductor lasers. Summary of the invention

[0003] In view of the technical problems existing in the prior art, the present invention proposes an evaluation method and system for characterizing the anti-return light capability of a semiconductor laser.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] Evaluation methods for characterizing the anti-return capability of semiconductor lasers include:

[0006] Build the measurement optical path;

[0007] The measurement optical path includes a semiconductor laser to be characterized, a forward pump signal combiner, a doped optical fiber, a reverse pump signal combiner, a laser light source operating in a wavelength range to be measured, and a laser power / spectrum acquisition subsystem, wherein the wavelength range to be measured is λ1 to λ2; the semiconductor laser to be characterized is connected to the doped optical fiber through a pump arm of the forward pump signal combiner, and the output end of the doped optical fiber is connected to the reverse pump signal combiner; the laser light source operating in the wavelength range to be measured is connected to the doped optical fiber through a pump arm of the reverse pump signal combiner; an idle pump arm of the forward pump signal combiner and the idle pump arm of the reverse pump signal combiner are respectively connected to the laser power / spectrum acquisition subsystem;

[0008] The laser power / spectrum acquisition subsystem uses an idle pump arm of the forward pump signal combiner to measure the power P of the laser with a wavelength range of λ1 to λ2 entering the semiconductor laser to be characterized. iAt the same time, the laser power / spectrum acquisition subsystem uses an idle pump arm of the reverse pump signal combiner to measure the power P of the output laser of the semiconductor laser to be characterized after being absorbed by the doped fiber. o and spectrum I(λ);

[0009] According to the doped fiber parameters, power P i , Power P o The average magnification F is obtained by summing up the spectrum I(λ), and the anti-return light capability of the semiconductor laser is evaluated based on the size of the average magnification F.

[0010] As a preferred solution, in the present invention, obtaining the average magnification F includes:

[0011] The remaining ratio a of the laser light with a wavelength range of λ1 to λ2 after passing through the doped optical fiber is obtained by using the doped optical fiber parameters;

[0012] Based on the remaining ratio a, power P i , power P o The average magnification F is calculated from the spectrum I(λ).

[0013] As a preferred solution, in the present invention, the calculation method of the average magnification F is as follows:

[0014]

[0015] In the present invention, the larger the average magnification factor F is, the stronger the amplification of the returned light is, and the weaker the anti-return light capability of the semiconductor laser is.

[0016] As a preferred solution, in the present invention, the measuring optical path further comprises a seed laser, and the seed laser is connected to the doped optical fiber through the signal arm of the forward pump signal combiner.

[0017] In the present invention, the central wavelength of the semiconductor laser to be characterized is not limited, and can be 790nm, 793nm, 808nm, 880nm, 915nm, 940nm, 976nm, 980nm, 1210nm, 1470nm, 1550nm, 1940nm, etc.

[0018] In the present invention, the operating current of the semiconductor laser to be characterized is not limited, and can be any current point within the calibrated operating current range of the semiconductor laser.

[0019] In the present invention, the operating temperature of the semiconductor laser to be characterized is not limited, and can be any temperature point within the calibrated operating temperature range of the semiconductor laser.

[0020] As a preferred solution, the present invention changes the working state parameters of the semiconductor laser, including the working current and the working temperature, and changes the return light parameters of the laser entering the semiconductor laser, including the wavelength range and power, to obtain the average magnification F of the return light of the semiconductor laser under different working states, for different wavelength ranges and different powers, and then comprehensively evaluates the anti-return light ability of the semiconductor laser.

[0021] In the present invention, the laser light source operating in the wavelength range to be measured can be implemented in any manner, and can be a fiber laser, a fiber-coupled semiconductor laser, a fiber-coupled solid laser, and the like.

[0022] In the present invention, the laser light source operating in the wavelength range to be measured outputs a laser wavelength range that does not overlap with the central wavelength of the semiconductor laser to be characterized.

[0023] In the present invention, the doped optical fiber is used to absorb the output laser of the semiconductor laser to be characterized, and the type and length of the doped optical fiber are selected based on the central wavelength of the semiconductor laser to be characterized.

[0024] In the present invention, the seed laser is used to avoid obvious spontaneous radiation noise in the doped optical fiber. The type of the seed laser is not limited, and the operating wavelength and power are selected based on the type of the doped optical fiber.

[0025] In the present invention, the number of pump arms of the forward pump signal combiner and the reverse pump signal combiner is not less than 2; the number of pump arms of the forward pump signal combiner and the reverse pump signal combiner may be the same or different;

[0026] In the present invention, the laser power / spectrum acquisition system includes power and spectrum acquisition functions, and is used to simultaneously acquire the power and spectrum morphology of the output laser.

[0027] The present invention provides an evaluation system for characterizing the anti-return light capability of a semiconductor laser, comprising a detection optical path and a data processing unit;

[0028] The measurement optical path includes a semiconductor laser to be characterized, a forward pump signal combiner, a doped optical fiber, a reverse pump signal combiner, a laser light source operating in a wavelength range to be measured, and a laser power / spectrum acquisition subsystem, wherein the wavelength range to be measured is λ1 to λ2; the semiconductor laser to be characterized is connected to the doped optical fiber through a pump arm of the forward pump signal combiner, and the output end of the doped optical fiber is connected to the reverse pump signal combiner; the laser light source operating in the wavelength range to be measured is connected to the doped optical fiber through a pump arm of the reverse pump signal combiner; an idle pump arm of the forward pump signal combiner and the idle pump arm of the reverse pump signal combiner are respectively connected to the laser power / spectrum acquisition subsystem;

[0029] The laser power / spectrum acquisition subsystem uses an idle pump arm of the forward pump signal combiner to measure the power P of the laser with a wavelength range of λ1 to λ2 entering the semiconductor laser to be characterized. i At the same time, the laser power / spectrum acquisition subsystem uses an idle pump arm of the reverse pump signal combiner to measure the power P of the output laser of the semiconductor laser to be characterized after being absorbed by the doped fiber. o and spectrum I(λ);

[0030] The laser power / spectrum acquisition subsystem is connected to the data processing unit by wire or wireless. The laser power / spectrum acquisition subsystem collects the power P i , power P o and spectrum I(λ) are transmitted to a data processing unit;

[0031] The data processing unit is based on the doped fiber parameters, power P i , Power P o The average magnification F is obtained by summing up the spectrum I(λ), and the anti-return light capability of the semiconductor laser is evaluated based on the size of the average magnification F.

[0032] As a preferred solution, the data processing unit includes:

[0033] A residual ratio calculation module, used to obtain the residual ratio a of the laser light with a wavelength range of λ1 to λ2 after passing through the doped optical fiber through the doped optical fiber parameters;

[0034] Average magnification calculation module, used to calculate the average magnification based on the remaining ratio a, power P i , power P o The average magnification F is calculated from the spectrum I(λ);

[0035] The evaluation module is used to evaluate the anti-return light capability of the semiconductor laser based on the average magnification F.

[0036] On the other hand, based on the above measurement optical path and the power P measured by it i , power P o and spectrum I(λ), the present invention provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the following steps are implemented:

[0037] Obtain the power P of the laser with a wavelength range of λ1 to λ2 entering the semiconductor laser to be characterized i And the power P of the output laser of the semiconductor laser to be characterized after being absorbed by the doped fiber o and spectrum I(λ);

[0038] The remaining ratio a of the laser light with a wavelength range of λ1 to λ2 after passing through the doped fiber is obtained by using the doped fiber parameters;

[0039] Based on the remaining ratio a, power P i , power P o The average magnification F is calculated from the spectrum I(λ);

[0040] The anti-return light capability of the semiconductor laser is evaluated based on the average magnification F.

[0041] On the other hand, based on the above measurement optical path and the power P measured by it i , power P o The present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the following steps when executing the computer program:

[0042] Obtain the power P of the laser with a wavelength range of λ1 to λ2 entering the semiconductor laser to be characterized i And the power P of the output laser of the semiconductor laser to be characterized after being absorbed by the doped fiber o and spectrum I(λ);

[0043] The remaining ratio a of the laser light with a wavelength range of λ1 to λ2 after passing through the doped fiber is obtained by using the doped fiber parameters;

[0044] Based on the remaining ratio a, power P i , power P o The average magnification F is calculated from the spectrum I(λ);

[0045] The anti-return light capability of the semiconductor laser is evaluated based on the average magnification F.

[0046] Through the above technical solution, the technical effects that the present invention can produce are:

[0047] The present invention uses the average magnification factor F of a semiconductor laser for laser light entering in the wavelength range of λ1 to λ2 to measure its anti-light-return capability. The larger the F is, the stronger the amplification of the light return is and the weaker the anti-light-return capability is. The average magnification factor F provides a quantitative evaluation index for the anti-light-return capability of a semiconductor laser.

[0048] The present invention can change the working state parameters of the semiconductor laser, such as the working current and working temperature, and the return light parameters, such as the wavelength range and power of the laser entering the semiconductor laser, to directly obtain the average magnification F of the semiconductor laser for return light of different wavelength ranges and different powers under different working states, and then comprehensively evaluate the anti-return light capability of the semiconductor laser, providing a quantitative index for the evaluation of semiconductor lasers suitable for different application occasions.

[0049] The invention has universality and can be widely applied to the evaluation of the anti-return light capability of different types of semiconductor lasers.

[0050] In summary, the present invention has important application value in the field of high-power laser technology, especially in the evaluation and optimization design of the anti-return light capability of semiconductor lasers used in high-power laser systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0052] Figure 1 A schematic diagram of the structure of an evaluation system for characterizing the anti-return light capability of a semiconductor laser provided in one embodiment of the present invention;

[0053] Figure 2 A schematic diagram of the structure of an evaluation system for characterizing the anti-return light capability of a semiconductor laser provided in one embodiment of the present invention;

[0054] Figure 3 1 is a graph showing the average magnification factor obtained in one embodiment of the present invention, that is, the average magnification factor F measured when the semiconductor laser to be characterized operates at different temperatures and has different return light powers, wherein the abscissa is the return light power (W) and the ordinate is the average magnification factor F;

[0055] Description of the numbers in the figure:

[0056] 1. Semiconductor laser to be characterized; 2. Forward pump signal combiner; 3. Doped optical fiber; 4. Reverse pump signal combiner; 5. Laser light source operating in the wavelength range to be measured; 6. Laser power / spectrum acquisition subsystem; 7. Data processing unit; 8. Seed laser. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention more clearly understood, the following will be used to clearly illustrate the spirit of the content disclosed by the present invention with the accompanying drawings and detailed descriptions. After understanding the embodiments of the content of the present invention, any person skilled in the art can change and modify the technology taught by the content of the present invention without departing from the spirit and scope of the content of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0058] In one embodiment of the present invention, a method for evaluating the anti-return light capability of a semiconductor laser is provided, comprising:

[0059] Build the measurement optical path;

[0060] like Figure 1 As shown, the measurement optical path includes a semiconductor laser 1 to be characterized, a forward pump signal combiner 2, a doped optical fiber 3, a reverse pump signal combiner 4, a laser light source 5 operating in a wavelength range to be measured, a laser power / spectrum acquisition subsystem 6 and a data processing unit 7, wherein the wavelength range to be measured is λ1 to λ2.

[0061] The semiconductor laser 1 to be characterized is connected to the doped optical fiber 3 through a pump arm of the forward pump signal combiner 2, and the output end of the doped optical fiber 3 is connected to the reverse pump signal combiner 4; the laser light source 5 working in the wavelength range to be measured is connected to the doped optical fiber 3 through a pump arm of the reverse pump signal combiner 4; an idle pump arm of the forward pump signal combiner 2 and the reverse pump signal combiner 4 are respectively connected to the laser power / spectrum acquisition subsystem 6;

[0062] The laser power / spectrum acquisition subsystem 6 uses an idle pump arm of the forward pump signal combiner 2 to measure the power P of the laser with a wavelength range of λ1 to λ2 entering the semiconductor laser 1 to be characterized. i At the same time, the laser power / spectrum acquisition subsystem 6 uses an idle pump arm of the reverse pump signal combiner 4 to measure the power P of the output laser of the semiconductor laser 1 to be characterized after being absorbed by the doped optical fiber 3. o and spectrum I(λ);

[0063] The laser power / spectrum acquisition subsystem 6 is connected to the data processing unit 7 by wire or wirelessly. The laser power / spectrum acquisition subsystem 6 acquires the power P i , power P o and the spectrum I(λ) are transmitted to the data processing unit 7;

[0064] The data processing unit 7 calculates the doped fiber parameters, power P i , power P o The average magnification F is obtained by summing up the spectrum I(λ), and the anti-return light capability of the semiconductor laser is evaluated based on the size of the average magnification F.

[0065] Furthermore, the data processing unit comprises:

[0066] A residual ratio calculation module is used to obtain the residual ratio a of the laser light in the wavelength range of λ1 to λ2 after passing through the doped optical fiber through the average absorption coefficient α0 (dB / m) of the doped optical fiber in the wavelength range of λ1 to λ2 and the length L (m) of the doped optical fiber, wherein a=10^(-α0×L / 10);

[0067] Average magnification calculation module, used to calculate the average magnification based on the remaining ratio a, power P i , power P o The average magnification F is calculated from the spectrum I(λ);

[0068] The evaluation module is used to evaluate the anti-return light capability of the semiconductor laser based on the average magnification F.

[0069] In one embodiment, the average magnification calculation method includes:

[0070] The average magnification F is calculated as follows:

[0071]

[0072] In the present invention, the larger the average magnification factor F is, the stronger the amplification of the returned light is, and the weaker the anti-return light capability of the semiconductor laser is. The average magnification factor F provides a quantitative evaluation index for the anti-return light capability of the high-power semiconductor laser.

[0073] In one embodiment of the present invention, a method for evaluating the anti-return light capability of a semiconductor laser is provided, wherein a measuring circuit is constructed such as Figure 2 As shown, the measurement optical path includes a semiconductor laser 1 to be characterized, a forward pump signal combiner 2, a doped optical fiber 3, a reverse pump signal combiner 4, a laser light source 5 operating in the wavelength range to be measured, a laser power / spectrum acquisition subsystem 6, a data processing unit 7 and a seed laser 8, wherein the wavelength range to be measured is λ1 to λ2.

[0074] The semiconductor laser 1 to be characterized and the seed laser 8 are connected to the doped optical fiber 3 through the pump arm and the signal arm of the forward pump signal combiner 2 respectively, and the output end of the doped optical fiber 3 is connected to the reverse pump signal combiner 4; the laser light source 5 working in the wavelength range to be measured is connected to the doped optical fiber 3 through a pump arm of the reverse pump signal combiner 4; an idle pump arm of the forward pump signal combiner 2 and the reverse pump signal combiner 4 are respectively connected to the laser power / spectrum acquisition subsystem 6; the seed laser emitted by the seed laser 8 is used to avoid obvious spontaneous radiation noise in the doped optical fiber.

[0075] The laser power / spectrum acquisition subsystem 6 uses an idle pump arm of the forward pump signal combiner 2 to measure the power P of the laser with a wavelength range of λ1 to λ2 entering the semiconductor laser 1 to be characterized. i At the same time, the laser power / spectrum acquisition subsystem 6 uses an idle pump arm of the reverse pump signal combiner 4 to measure the power P of the output laser of the semiconductor laser 1 to be characterized after being absorbed by the doped optical fiber 3. o and spectrum I(λ);

[0076] The laser power / spectrum acquisition subsystem 6 is connected to the data processing unit 7 by wire or wirelessly. The laser power / spectrum acquisition subsystem 6 acquires the power P i , power P o and the spectrum I(λ) are transmitted to the data processing unit 7;

[0077] The data processing unit 7 calculates the doped fiber parameters, power P i , power P o The average magnification F is obtained by summing up the spectrum I(λ), and the anti-return light capability of the semiconductor laser is evaluated based on the size of the average magnification F.

[0078] In the present invention, the central wavelength of the semiconductor laser to be characterized is not limited, and those skilled in the art can select it as needed, that is, the central wavelength of the semiconductor laser to be characterized selected in different embodiments is not limited, and can be 790nm, 793nm, 808nm, 880nm, 915nm, 940nm, 976nm, 980nm, 1210nm, 1470nm, 1550nm, 1940nm, etc.

[0079] In the present invention, the working current of the semiconductor laser to be characterized is not limited, and those skilled in the art can select it as needed, and it can be any current point within the calibrated working current range of the semiconductor laser.

[0080] In the present invention, the operating temperature of the semiconductor laser to be characterized is not limited, and those skilled in the art can select it as needed, and it can be any temperature point within the calibrated operating temperature range of the semiconductor laser.

[0081] The present invention changes the working state parameters of the semiconductor laser, including the working current and the working temperature, and changes the return light parameters of the laser entering the semiconductor laser, including the wavelength range and the power, to obtain the average magnification F of the return light of the semiconductor laser under different working states, in different wavelength ranges and at different powers, and then comprehensively evaluates the anti-return light capability of the semiconductor laser.

[0082] In the present invention, the implementation method of the laser light source working in the wavelength range to be measured is not limited, and those skilled in the art can select it according to needs, which can be a fiber laser, a fiber-coupled semiconductor laser, a fiber-coupled solid laser, etc.

[0083] In the present invention, the laser light source operating in the wavelength range to be measured outputs a laser wavelength range that does not overlap with the central wavelength of the semiconductor laser to be characterized.

[0084] In the present invention, the doped optical fiber is used to absorb the output laser of the semiconductor laser to be characterized. Those skilled in the art can select the doped optical fiber type and length based on the central wavelength of the semiconductor laser to be characterized according to the common knowledge and conventional technical means in the field.

[0085] In the present invention, the seed laser is used to avoid obvious spontaneous radiation noise in the doped optical fiber. The type of the seed laser is not limited, and the operating wavelength and power are selected based on the type of the doped optical fiber.

[0086] In the present invention, the forward pump signal beam combiner and the reverse pump signal beam combiner have pump arms of no less than 2; the numbers of pump arms of the forward pump signal beam combiner and the reverse pump signal beam combiner may be the same or different.

[0087] In the present invention, the laser power / spectrum acquisition system includes power and spectrum acquisition functions, and is used to simultaneously acquire the power and spectrum morphology of the output laser.

[0088] Matters not covered by the present invention are known technologies.

[0089] The present invention can quantitatively evaluate the anti-return light capability of different types of semiconductor lasers under different working conditions for lasers of different wavelength ranges and different powers. By constructing a measurement optical path, the power P of the laser with a wavelength range of λ1 to λ2 entering the semiconductor laser to be characterized is measured. i And the power P of the output laser of the semiconductor laser to be characterized after being absorbed by the doped fiber o and spectrum I(λ), based on the remaining proportion a, power P i , power P o The average magnification F is calculated from the spectrum I(λ); the anti-return capability of the semiconductor laser is evaluated based on the average magnification F. The evaluation method provided by the present invention is universal and can evaluate the anti-return capability of different types of semiconductor lasers under different working conditions for lasers of different wavelength ranges and different powers.

[0090] Without loss of generality, a specific embodiment is provided below, wherein the measurement circuit constructed is as follows: Figure 2As shown, the measurement optical path includes a semiconductor laser 1 to be characterized, a forward pump signal combiner 2, a doped fiber 3, a reverse pump signal combiner 4, a laser light source 5 operating in the wavelength range to be measured, a laser power / spectrum acquisition subsystem 6, a data processing unit 7, and a seed laser 8, wherein the wavelength range to be measured is λ1 to λ2. The operating wavelength of the high-power semiconductor laser 1 to be characterized is 976nm, the operating current is 13A, and the operating temperature is 10℃ or 20℃. The output power of the seed laser 8 is 10W, and the operating wavelength is 1064nm. The forward pump signal combiner 2 and the reverse pump signal combiner 4 are both (6+1)×1 pump signal combiners; the doped fiber 3 is an ytterbium-doped fiber with a fiber length of 2.65m; the output spectrum range of the laser light source 5 operating in the wavelength range to be measured is 967nm to 972nm, and the output power is adjustable.

[0091] The semiconductor laser 1 to be characterized and the seed laser 8 are connected to the doped optical fiber 3 through the pump arm and the signal arm of the forward pump signal combiner 2 respectively, and the output end of the doped optical fiber 3 is connected to the reverse pump signal combiner 4; the laser light source 5 working in the wavelength range to be measured is connected to the doped optical fiber 3 through a pump arm of the reverse pump signal combiner 4; an idle pump arm of the forward pump signal combiner 2 and the reverse pump signal combiner 4 are respectively connected to the laser power / spectrum acquisition subsystem 6.

[0092] The laser power / spectrum acquisition subsystem 6 uses an idle pump arm of the forward pump signal combiner 2 to measure the power P of the laser with a wavelength range of λ1 to λ2 entering the semiconductor laser 1 to be characterized. i At the same time, the laser power / spectrum acquisition subsystem 6 uses an idle pump arm of the reverse pump signal combiner 4 to measure the power P of the output laser of the semiconductor laser 1 to be characterized after being absorbed by the doped optical fiber 3. o and spectrum I(λ).

[0093] The laser power / spectrum acquisition subsystem 6 is connected to the data processing unit 7 by wire or wirelessly. The laser power / spectrum acquisition subsystem 6 acquires the power P i , power P o The spectrum I(λ) is transmitted to the data processing unit 7 in real time.

[0094] The data processing unit 7 calculates the doped fiber parameters, power P i , power P o The average magnification F is obtained by summing up the spectrum I(λ), and the anti-return light capability of the semiconductor laser is evaluated based on the size of the average magnification F.

[0095] The average magnification F is calculated as follows:

[0096]

[0097] The larger the average magnification factor F is, the stronger the amplification of the returned light is, and the weaker the anti-return light ability of the semiconductor laser is. The average magnification factor F provides a quantitative evaluation index for the anti-return light ability of high-power semiconductor lasers.

[0098] At different working temperatures, the return light power P i At the same time, the analysis results of the average magnification F of the return light of the high-power semiconductor laser 1 to be characterized are shown in the attached figure. Figure 3 As shown. Figure 3 The results show that the average magnification at an operating temperature of 10°C is significantly higher than that at an operating temperature of 20°C, which indicates that the operating temperature will have a significant impact on the anti-return capability of high-power semiconductor lasers. The anti-return capability at an operating temperature of 20°C is significantly stronger than that at an operating temperature of 10°C. Figure 3 The results also show that as the return light power increases, the anti-return light ability of the high-power semiconductor laser gradually weakens and then tends to be stable. Therefore, the evaluation method provided by the present invention can not only characterize the anti-return light ability of the high-power semiconductor laser, but more importantly, it can quantitatively evaluate the anti-return light ability of the high-power semiconductor laser under different working conditions for lasers of different wavelength ranges and different powers. The above function has important application value in the evaluation and optimization design of the anti-return light ability of semiconductor lasers in high-power laser systems.

[0099] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for evaluating the anti-return light capability of a semiconductor laser, characterized in that: include: Build the measurement optical path; The measurement optical path includes a semiconductor laser to be characterized, a forward pump signal combiner, a doped optical fiber, a reverse pump signal combiner, a laser light source operating in a wavelength range to be measured, and a laser power / spectrum acquisition subsystem, wherein the wavelength range to be measured is λ1 to λ2; the semiconductor laser to be characterized is connected to the doped optical fiber through a pump arm of the forward pump signal combiner, and the output end of the doped optical fiber is connected to the reverse pump signal combiner; the laser light source operating in the wavelength range to be measured is connected to the doped optical fiber through a pump arm of the reverse pump signal combiner; an idle pump arm of the forward pump signal combiner and the idle pump arm of the reverse pump signal combiner are respectively connected to the laser power / spectrum acquisition subsystem; The laser power / spectrum acquisition subsystem uses an idle pump arm of the forward pump signal combiner to measure the power P of the laser with a wavelength range of λ1 to λ2 entering the semiconductor laser to be characterized. i At the same time, the laser power / spectrum acquisition subsystem uses an idle pump arm of the reverse pump signal combiner to measure the power P of the output laser of the semiconductor laser to be characterized after being absorbed by the doped fiber. o and spectrum I(λ); According to the doped fiber parameters, power P i , Power P o The average magnification F is obtained by summing up the spectrum I(λ), and the anti-return light capability of the semiconductor laser is evaluated based on the size of the average magnification F.

2. The evaluation method for characterizing the anti-return light capability of a semiconductor laser according to claim 1, characterized in that: Get the average magnification F, including: The remaining ratio a of the laser light with a wavelength range of λ1 to λ2 after passing through the doped optical fiber is obtained by using the doped optical fiber parameters; Based on the remaining ratio a, power P i , Power P o The average magnification F is calculated from the spectrum I(λ).

3. The evaluation method for characterizing the anti-return light capability of a semiconductor laser according to claim 2, characterized in that: The average magnification F is calculated as follows:

4. The evaluation method for characterizing the anti-return light capability of a semiconductor laser according to claim 1, 2 or 3, characterized in that: The larger the average magnification F is, the stronger the return light is amplified, and the weaker the semiconductor laser's ability to resist return light is.

5. The evaluation method for characterizing the anti-return light capability of a semiconductor laser according to claim 4, characterized in that: The measurement optical path also includes a seed laser, which is connected to the doped optical fiber through a signal arm of a forward pump signal combiner.

6. The evaluation method for characterizing the anti-return light capability of a semiconductor laser according to claim 1, 2, 3 or 5, characterized in that: The central wavelength of the semiconductor laser to be characterized is 790 nm, 793 nm, 808 nm, 880 nm, 915 nm, 940 nm, 976 nm, 980 nm, 1210 nm, 1470 nm, 1550 nm or 1940 nm; The operating current of the semiconductor laser to be characterized is any current point within the calibrated operating current range of the semiconductor laser; The operating temperature of the semiconductor laser to be characterized is any temperature point within the calibrated operating temperature range of the semiconductor laser.

7. The evaluation method for characterizing the anti-return light capability of a semiconductor laser according to claim 6, characterized in that: By changing the working state parameters of the semiconductor laser, including the working current and working temperature, and changing the return light parameters of the laser entering the semiconductor laser, including the wavelength range and power, the average amplification factor F of the return light of the semiconductor laser under different working states, different wavelength ranges, and different powers is obtained, and then the anti-return light ability of the semiconductor laser is comprehensively evaluated.

8. The evaluation method for characterizing the anti-return light capability of a semiconductor laser according to claim 1, 2, 3, 5 or 7, characterized in that: The laser light source operating in the wavelength range to be measured is a fiber laser, a fiber-coupled semiconductor laser or a fiber-coupled solid-state laser.

9. The evaluation method for characterizing the anti-return light capability of a semiconductor laser according to claim 1, characterized in that: The laser light source operating in the wavelength range to be measured has an output laser wavelength range that does not overlap with the central wavelength of the semiconductor laser to be characterized.

10. An evaluation system for characterizing the anti-return light capability of a semiconductor laser, characterized in that: It includes a detection optical path and a data processing unit; The measurement optical path includes a semiconductor laser to be characterized, a forward pump signal combiner, a doped optical fiber, a reverse pump signal combiner, a laser light source operating in a wavelength range to be measured, and a laser power / spectrum acquisition subsystem, wherein the wavelength range to be measured is λ1 to λ2; the semiconductor laser to be characterized is connected to the doped optical fiber through a pump arm of the forward pump signal combiner, and the output end of the doped optical fiber is connected to the reverse pump signal combiner; the laser light source operating in the wavelength range to be measured is connected to the doped optical fiber through a pump arm of the reverse pump signal combiner; an idle pump arm of the forward pump signal combiner and the idle pump arm of the reverse pump signal combiner are respectively connected to the laser power / spectrum acquisition subsystem; The laser power / spectrum acquisition subsystem uses an idle pump arm of the forward pump signal combiner to measure the power P of the laser with a wavelength range of λ1 to λ2 entering the semiconductor laser to be characterized. i At the same time, the laser power / spectrum acquisition subsystem uses an idle pump arm of the reverse pump signal combiner to measure the power P of the output laser of the semiconductor laser to be characterized after being absorbed by the doped fiber. o and spectrum I(λ); The laser power / spectrum acquisition subsystem is connected to the data processing unit by wire or wireless. The laser power / spectrum acquisition subsystem collects the power P i , Power P o and spectrum I(λ) are transmitted to a data processing unit; The data processing unit is based on the doped fiber parameters, power P i , Power P o The average magnification F is obtained by summing up the spectrum I(λ), and the anti-return light capability of the semiconductor laser is evaluated based on the size of the average magnification F.

11. The evaluation system for characterizing the anti-return light capability of a semiconductor laser according to claim 10, characterized in that: The data processing unit includes: A residual ratio calculation module, used to obtain the residual ratio a of the laser light with a wavelength range of λ1 to λ2 after passing through the doped optical fiber through the doped optical fiber parameters; Average magnification calculation module, used to calculate the average magnification based on the remaining ratio a, power P i , Power P o The average magnification F is calculated from the spectrum I(λ); The evaluation module is used to evaluate the anti-return light capability of the semiconductor laser based on the average magnification F.

12. The evaluation system for characterizing the anti-return light capability of a semiconductor laser according to claim 11, characterized in that: The average magnification F is calculated as follows:

13. The evaluation system for characterizing the anti-return light capability of a semiconductor laser according to claim 10, 11 or 12, characterized in that: The larger the average magnification F is, the stronger the return light is amplified, and the weaker the semiconductor laser's ability to resist return light is.

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