Evaluation methods, apparatus, and systems for characterizing the anti-backlight capability of fiber lasers

Abstract

This invention provides a method, apparatus, and system for evaluating the anti-backlight capability of a fiber laser, including obtaining the backlight wavelength λ of the fiber laser to be characterized in its current operating state. t The analysis focuses on the output power and output spectrum of a fiber laser at different return power levels as the return power increases. It calculates the effective output power within the effective operating wavelength range of the fiber laser output at different return power levels, normalizes the effective output power using its maximum value, and obtains the effective output power ratio under different return power levels. Based on this ratio, the analysis evaluates the fiber laser's performance at wavelength λ. t The invention assesses the resistance to backlighting from lasers with different backlight powers. It enables a quantitative evaluation of the resistance to backlighting from different wavelengths and powers of fiber lasers operating in different states.

Description

Technical Field

[0001] This invention relates to the field of high-power fiber laser technology, and in particular to an evaluation method, apparatus and system for characterizing the anti-backlight capability of fiber lasers. Background Technology

[0002] Fiber lasers have advantages such as compact structure, high conversion efficiency, good beam quality, and convenient thermal management, and have been widely used in industrial processing, scientific research, military defense and other fields.

[0003] In practical applications of fiber lasers, especially when used as pump lasers for other lasers, it is inevitable that laser light of other wavelengths will return to the fiber laser. When this portion of laser light is located within the gain spectrum range of the gain fiber in the fiber laser and is amplified, the output power, spectrum, and temporal stability of the fiber laser may all exhibit significant degradation, which limits the application effectiveness of fiber lasers in practical systems.

[0004] To ensure the stable operation of fiber lasers, it is necessary to test and evaluate their anti-backlight capability. However, there are no publicly reported technical solutions for testing and evaluating the anti-backlight capability of fiber lasers in the current technology. Therefore, there is an urgent need for a solution that can test and evaluate the anti-backlight capability of fiber lasers. Summary of the Invention

[0005] To address the technical problems existing in the prior art, this invention proposes an evaluation method, apparatus, and system for characterizing the anti-backlight capability of fiber lasers. This method can quantitatively evaluate the anti-backlight capability of different types of fiber lasers operating in different states against lasers of different wavelengths and powers.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] On one hand, the present invention provides an evaluation method for characterizing the anti-backlight capability of fiber lasers, comprising:

[0008] Obtain the return wavelength λ of the fiber laser to be characterized in its current operating state. t As the return light power increases from a small value, the output power and output spectrum of the fiber laser at different return light powers are analyzed.

[0009] When calculating different return powers, the effective output power P of the fiber laser output laser within the effective operating wavelength range is... e ;

[0010] For effective output power P e By normalizing its maximum value, the effective output power ratio R under different backlight powers is obtained. e ;

[0011] Based on the effective output power ratio R under different backlight powers e Evaluation of fiber lasers for wavelength λ t The strength of anti-backlight capability of lasers with different backlight power.

[0012] Furthermore, let the current backlight power be P. i The return power is P i The output power of the fiber laser is P o The output spectrum is I(λ);

[0013] Calculate the return light power as P i At that time, the effective output power P of the fiber laser output laser within the effective operating wavelength range e ,have:

[0014]

[0015] Where λ0 is the operating wavelength of the fiber laser, and Δλ is the operating bandwidth of the fiber laser.

[0016] Furthermore, the return power is P i The effective output power ratio R e ,for:

[0017]

[0018] Furthermore, the present invention utilizes a wavelength of λ t Power P i Under laser injection, the effective output power ratio R of the fiber laser e Its resistance to backlighting is measured specifically by the backlighting power being P. i The effective output power ratio R e The smaller the value, the higher the wavelength λ. t Power P i The greater the influence of the laser on the fiber laser, the more effective the fiber laser is at wavelength λ. t Power is P i The weaker the anti-reflection ability of the laser.

[0019] On the other hand, the present invention provides an evaluation device for characterizing the anti-backlight capability of a fiber laser, comprising:

[0020] The first module is used to obtain the return wavelength λ of the fiber laser to be characterized in its current operating state. t As the return power increases from small to large, the output power and output spectrum of the fiber laser at different return powers are analyzed.

[0021] The second module is used to calculate the effective output power P of the fiber laser output laser within the effective operating wavelength range for different return light powers. e Let the current backlight power be P. i The return power is P i The output power of the fiber laser is P o The output spectrum is I(λ);

[0022] Calculate the return power as P i At that time, the effective output power P of the fiber laser output laser within the effective operating wavelength range e ,have:

[0023]

[0024] Where λ0 is the operating wavelength of the fiber laser, and Δλ is the operating bandwidth of the fiber laser;

[0025] The third module is used to measure the effective output power P. e By normalizing its maximum value, the effective output power ratio R under different backlight powers is obtained. e The return power is P i The effective output power ratio R e ,for:

[0026]

[0027] The fourth module is used to determine the effective output power ratio R based on different return power levels. e Evaluation of fiber lasers for wavelength λ t The strength of anti-backlight capability of lasers with different backlight powers, specifically: backlight power is P i The effective output power ratio R e The smaller the value, the higher the wavelength λ. t Power P i The greater the influence of the laser on the fiber laser, the more effective the fiber laser is at wavelength λ. t Power is P i The weaker the anti-reflection ability of the laser.

[0028] On the other hand, the present invention provides an evaluation system for characterizing the anti-backlight capability of a fiber laser, comprising: a broadband laser source, a tunable bandpass filter, a broadband power amplifier, a fiber coupler, a fiber wavelength division multiplexer, the fiber laser to be characterized, a laser power / spectral acquisition subsystem, and a data processing unit.

[0029] The output of a broadband laser source is connected to the input of a tunable bandpass filter, and the output of the tunable bandpass filter is connected to the input of a broadband power amplifier. The broadband laser source obtains a wavelength of λ through the tunable bandpass filter. t The laser was then used to power a wavelength of λ. t The laser is amplified, wherein the output power of the broadband power amplifier is adjustable; the output end of the broadband power amplifier is connected to the input arm of the fiber coupler, the splitting ratio of the fiber coupler is a:1, and the first output arm of the fiber coupler is the output laser arm with an output laser ratio of a / (a+1). The first output arm of the fiber coupler is connected to the fiber wavelength division multiplexer, which can transmit laser wavelengths of λ. t The second fiber arm; the second output arm of the fiber coupler is an output laser arm with an output laser ratio of 1 / (a+1), and the second output arm of the fiber coupler is connected to the laser power / spectrum acquisition subsystem, which measures its power P1; the fiber wavelength division multiplexer can transmit lasers with a wavelength of λ. t The first fiber arm with wavelength λ0 is connected to the fiber laser to be characterized. In the fiber wavelength division multiplexer, the third fiber arm with a laser wavelength of λ0 can be connected to the laser power / spectral acquisition subsystem. The output power P of the fiber laser to be characterized is measured by the laser power / spectral acquisition subsystem. o The laser power / spectral acquisition subsystem and data processing module achieve real-time communication and measurement of the output spectrum I(λ), and the return power injected into the fiber laser to be characterized satisfies P. i = a × P1.

[0030] Furthermore, the fiber laser to be characterized is a fiber oscillator, a superfluorescent fiber laser, a Raman fiber laser, a random fiber laser, or a fiber amplifier.

[0031] Furthermore, the operating temperature of the fiber laser to be characterized is any temperature point covering the calibrated operating temperature range of the fiber laser.

[0032] Furthermore, by changing the operating parameters of the fiber laser, including the operating wavelength, operating power, and / or operating temperature, the backlight parameters of the laser entering the fiber laser are changed. These backlight parameters include the wavelength and power of the laser entering the fiber laser. The effective output power ratio Re of the fiber laser under different operating conditions for backlight of different wavelengths and different powers is obtained, thereby comprehensively evaluating the anti-backlight capability of the fiber laser.

[0033] Compared with the prior art, the technical effects that this invention can produce are:

[0034] 1. The evaluation method for characterizing the anti-backlight capability of fiber lasers proposed in this invention utilizes a wavelength of λt Power P i Under laser injection, the effective output power ratio R of the fiber laser to be characterized is calculated. e Its resistance to backlighting is measured by the backlighting power, specifically P. i The effective output power ratio R e The smaller the value, the higher the wavelength λ. t Power P i The greater the influence of the laser on the fiber laser, the more effective the fiber laser is at wavelength λ. t Power is P i The weaker the anti-backlight capability of the laser, the less effective it is at resisting backlighting. The backlighting power proposed in this invention is P. i The effective output power ratio R e This provides a quantitative evaluation index for the anti-backlight capability of fiber lasers.

[0035] 2. The evaluation system for characterizing the anti-backlight capability of fiber lasers proposed in this invention can directly obtain the effective output power ratio R of the fiber laser for backlighting of different wavelength ranges and different power levels under different operating conditions by changing backlighting parameters such as the operating wavelength and power of the laser entering the fiber laser, and by changing the operating state parameters such as the operating wavelength, operating power, and operating temperature of the fiber laser. e This allows for a comprehensive evaluation of the anti-backlight capability of fiber lasers, providing quantitative indicators for evaluating fiber lasers suitable for different applications.

[0036] 3. This invention is universal. It can be used to evaluate the anti-backlight capability of the same type of fiber laser under different backlight wavelength ranges and different backlight power levels. It can also be widely applied to evaluate the anti-backlight capability of different types of fiber lasers.

[0037] In summary, this invention has significant application value in the field of fiber laser technology, particularly in the evaluation and optimization design of fiber laser anti-backlight capability. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the structure of an evaluation system for characterizing the anti-backlight capability of a fiber laser, provided in one embodiment.

[0040] Figure 2This is a graph showing the ratio of effective output power measured when the fiber laser to be characterized operates at different return powers in one embodiment.

[0041] Numbering on the map:

[0042] 1. Broadband laser source; 2. Tunable bandpass filter; 3. Broadband power amplifier; 4. Fiber optic coupler; 4-1. Input arm of fiber optic coupler; 4-2. First output arm; 4-3. Second output arm; 5. Fiber wavelength division multiplexer; 5-1. First fiber arm; 5-2. Second fiber arm; 5-3. Third fiber arm; 6. Fiber laser to be characterized; 7. Laser power / spectrum acquisition subsystem; 8. Data processing unit. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0044] In one embodiment, a method for evaluating the anti-backlight capability of a fiber laser is provided, comprising:

[0045] (1) Obtain the return wavelength λ of the fiber laser to be characterized in its current operating state. t As the return light power increases from a small value, the output power and output spectrum of the fiber laser at different return light powers are analyzed.

[0046] (2) Calculate the effective output power P of the fiber laser output laser within the effective operating wavelength range for different return light powers. e ;

[0047] (3) For the effective output power P e By normalizing its maximum value, the effective output power ratio R under different backlight powers is obtained. e ;

[0048] (4) Effective output power ratio R based on different backlight power e Evaluation of fiber lasers for wavelength λ t The strength of anti-backlight capability of lasers with different backlight power.

[0049] It is understood that the current operating state of the fiber laser to be characterized is not limited; operating parameters such as the operating wavelength, operating power, and operating temperature can be changed to place the fiber laser in different operating states. Using the evaluation method for characterizing the anti-backlight capability of a fiber laser provided in the above embodiments, the effective output power ratio R of the fiber laser under different operating states and for different wavelength ranges and power backlights can be directly obtained. e This allows for a comprehensive evaluation of the anti-backlight capability of fiber lasers.

[0050] In step (2) above, let the current backlight power be P. i The return power is P i The output power of the fiber laser is P o The output spectrum is I(λ);

[0051] Calculate the return light power as P i At that time, the effective output power P of the fiber laser output laser within the effective operating wavelength range e ,have:

[0052]

[0053] Where λ0 is the operating wavelength of the fiber laser, and Δλ is the operating bandwidth of the fiber laser.

[0054] In step (3) above, the backlight power is P. i The effective output power ratio R e ,for:

[0055]

[0056] In step (4) above, the wavelength λ is utilized. t Power P i Under laser injection, the effective output power ratio R of the fiber laser e Its resistance to backlighting is measured specifically by the backlighting power being P. i The effective output power ratio R e The smaller the value, the higher the wavelength λ. t Power P i The greater the influence of the laser on the fiber laser, the more effective the fiber laser is at wavelength λ. t Power is P i The weaker the anti-reflection ability of the laser.

[0057] The evaluation method provided by this invention is universal and can be used to evaluate the anti-backlight capability of the same type of fiber laser under different backlight wavelength ranges and different backlight power levels. It can also evaluate the anti-backlight capability of different types of fiber lasers under different operating conditions for lasers of different wavelengths and different power.

[0058] Another embodiment provides an evaluation device for characterizing the anti-backlight capability of a fiber laser, comprising:

[0059] The first module is used to obtain the return wavelength λ of the fiber laser to be characterized in its current operating state. t As the return power increases from small to large, the output power and output spectrum of the fiber laser at different return powers are analyzed.

[0060] The second module is used to calculate the effective output power P of the fiber laser output laser within the effective operating wavelength range for different return light powers. e Let the current backlight power be P. i The return power is P i The output power of the fiber laser is P o The output spectrum is I(λ);

[0061] Calculate the return power as P i At that time, the effective output power P of the fiber laser output laser within the effective operating wavelength range e ,have:

[0062]

[0063] Where λ0 is the operating wavelength of the fiber laser, and Δλ is the operating bandwidth of the fiber laser;

[0064] The third module is used to measure the effective output power P. e By normalizing its maximum value, the effective output power ratio R under different backlight powers is obtained. e The return power is P i The effective output power ratio R e ,for:

[0065]

[0066] The fourth module is used to determine the effective output power ratio R based on different return power levels. e Evaluation of fiber lasers for wavelength λ t The strength of anti-backlight capability of lasers with different backlight powers, specifically: backlight power is P i The effective output power ratio R e The smaller the value, the higher the wavelength λ. t Power P i The greater the influence of the laser on the fiber laser, the more effective the fiber laser is at wavelength λ. t Power is P i The weaker the anti-reflection ability of the laser.

[0067] One embodiment, referring to Figure 1 This invention provides an evaluation system for characterizing the anti-backlight capability of a fiber laser, comprising: a broadband laser source 1, a tunable bandpass filter 2, a broadband power amplifier 3, an optical fiber coupler 4, an optical fiber wavelength division multiplexer 5, the fiber laser to be characterized 6, a laser power / spectrum acquisition subsystem 7, and a data processing unit 8. The optical fiber coupler 4 has three optical fiber arms: input arms 4-1, a first output arm 4-2 with an output laser ratio of a / (a+1), and a second output arm 4-3 with an output laser ratio of 1 / (a+1). The optical fiber wavelength division multiplexer 5 has three optical fiber arms, each capable of transmitting light at a wavelength of λ... t The first fiber arm 5-1 of the laser with wavelength λ0 can pass through wavelength λ t The second fiber arm 5-2 of the laser can transmit a laser with a wavelength of λ0, and the third fiber arm 5-3 can transmit a laser with a wavelength of λ0.

[0068] The output of broadband laser source 1 is connected to the input of tunable bandpass filter 2, and the output of tunable bandpass filter 2 is connected to the input of broadband power amplifier 3. The broadband laser source obtains a wavelength of λ through the tunable bandpass filter. t The laser was then used to power a wavelength of λ. t The laser is amplified; the output of the broadband power amplifier 3 is connected to the input arm 4-1 of the fiber coupler, the splitting ratio of the fiber coupler 4 is a:1, and the first output arm 4-2 of the fiber coupler 4 is the output arm with an output laser ratio of a / (a+1). The first output arm 4-2 of the fiber coupler 4 is connected to the fiber wavelength division multiplexer 5, which can transmit laser wavelengths of λ. t The second fiber arm 5-2; the second output arm 4-3 of the fiber coupler 4 is an output arm with an output laser ratio of 1 / (a+1), and the second output arm 4-3 of the fiber coupler 4 is connected to the laser power / spectrum acquisition subsystem 7, whose power P1 is measured by the laser power / spectrum acquisition subsystem 7; the fiber wavelength division multiplexer 5 can transmit laser wavelengths of λ t The first fiber arm 5-1 with a laser wavelength of λ0 is connected to the fiber laser 6 to be characterized. The third fiber arm 5-3 in the fiber wavelength division multiplexer 5 can be connected to the laser power / spectrum acquisition subsystem 7 through the laser wavelength of λ0. The output power P of the fiber laser 6 to be characterized is measured by the laser power / spectrum acquisition subsystem 7. o The laser power / spectral acquisition subsystem 7 and the data processing module 8 achieve real-time communication and measurement of the output spectrum I(λ). The return power injected into the fiber laser 6 to be characterized satisfies P. i = a × P1.

[0069] For example Figure 1 The evaluation system for characterizing the anti-backlight capability of fiber lasers, as shown, includes a method for implementing this evaluation, as follows:

[0070] A broadband laser source obtains a wavelength of λ through a tunable bandpass filter. t The laser was then used to power a wavelength of λ. t The laser power is amplified by gradually increasing the return power P injected into the fiber laser to be characterized, starting from 0. i The output power and output spectrum of the fiber laser to be characterized were collected simultaneously at different return power.

[0071] Data processing module 8 calculates the effective output power P of the fiber laser output laser within the effective operating wavelength range when different return powers are applied. e ;

[0072] Data processing module 8 outputs effective power P e By normalizing its maximum value, the effective output power ratio R under different backlight powers is obtained. e ;

[0073] Data processing module 8 is based on the effective output power ratio R under different backlight powers. e Evaluation of fiber lasers for wavelength λ t The strength of anti-backlight capability of lasers with different backlight power.

[0074] Furthermore, for such Figure 1 The evaluation system shown, characterizing the anti-backlight capability of a fiber laser, can also change the backlight parameters of the laser entering the fiber laser by altering its operating parameters, including operating wavelength, operating power, and operating temperature. These backlight parameters include the laser's wavelength and power. This allows obtaining the effective output power ratio R of the fiber laser under different operating conditions for backlight of different wavelengths and powers. e This allows for a comprehensive evaluation of the anti-backlight capability of fiber lasers.

[0075] In the above embodiments, the type of fiber laser to be characterized is not limited, and can be a fiber oscillator, a superfluorescent fiber laser, a Raman fiber laser, a random fiber laser, and a fiber amplifier, etc.

[0076] In the above embodiments, the operating wavelength of the fiber laser to be characterized is not limited and can be any wavelength covering the calibrated operating wavelength range of the fiber laser.

[0077] In the above embodiments, the operating power of the fiber laser to be characterized is not limited and can be any power point covering the calibrated operating power range of the fiber laser.

[0078] In the above embodiments, the operating temperature of the fiber laser to be characterized is not limited and can be any temperature point covering the calibrated operating temperature range of the fiber laser.

[0079] In the above embodiments, the broadband laser source can be implemented in any way, such as a fiber laser, a fiber-coupled semiconductor laser, or a fiber-coupled solid-state laser.

[0080] In the above embodiments, the broadband power amplifier can be implemented in various ways, such as a fiber laser amplifier, a fiber-coupled semiconductor laser amplifier, or a fiber-coupled solid-state laser amplifier.

[0081] In the above embodiments, the value of 'a' in the optical fiber coupler splitting ratio 'a:1' is not limited; 'a' can be greater than 1, less than 1, or equal to 1.

[0082] In the above embodiments, the laser power / spectral acquisition system includes power and spectral acquisition functions to simultaneously acquire the power and spectral morphology of the output laser.

[0083] The data processing module described in the above embodiments communicates in real time with the laser power / spectrum acquisition system to obtain the wavelength λ entering the fiber laser to be characterized. t Laser power P i And the output power P of the fiber laser to be characterized o And the output spectrum I(λ), and then, according to the evaluation method for characterizing the anti-backlight capability of fiber lasers proposed in this invention, the effective output power ratio R can be calculated. e .

[0084] To further illustrate the adoption Figure 1 The evaluation system and method for characterizing the anti-backlight capability of fiber lasers provided in the illustrated embodiments have unique advantages. The following uses a specific application example to illustrate the anti-backlight capability of fiber lasers under different backlight powers.

[0085] In this application example, without loss of generality, the broadband laser source 1 is a broadband superfluorescent fiber laser with an output spectral range of 1010 nm to 1100 nm; the tunable bandpass filter 2 has a pass wavelength of 1080 nm; the broadband power amplifier 3 is a fiber amplifier with adjustable output power and a maximum output power of 1 W; the fiber coupler 4 has a splitting ratio of 9:1; the fiber wavelength division multiplexer 5 has pass wavelengths of 1018 nm, 1080 nm, and 1018 nm / 1080 nm, respectively; the fiber laser 6 to be characterized is a cascaded pump source for a high-power fiber laser system, with an operating wavelength of 1018 nm, an operating bandwidth of 1 nm, an output power of ~50 W, and an operating temperature of 20 °C.

[0086] The effective output power ratio diagram of the fiber laser 6 to be characterized, obtained by measuring different return power, is shown in the attached figure. Figure 2 As shown. (From the appendix) Figure 2 The results show that as the backlight power increases, the effective output power ratio gradually decreases, indicating that the backlight has an increasingly significant impact on fiber lasers, and the fiber laser's resistance to backlight decreases. Furthermore, from the attached... Figure 2 The result also yields the maximum return power required to ensure the fiber laser's output power is not less than a certain value. For example, when the fiber laser's output power is required to be no less than 40W, the corresponding effective output power ratio should be no less than 80%, at which point the maximum return power at the 1080nm wavelength is ~172mW.

[0087] Therefore, the evaluation method provided by this invention can not only characterize the anti-backlight capability of fiber lasers, but more importantly, it can quantitatively evaluate the anti-backlight capability of fiber lasers under different operating conditions (such as different operating temperatures) for lasers of different wavelengths and powers. These functions have significant application value for evaluating and optimizing the anti-backlight capability of fiber lasers in practical applications.

[0088] Matters not covered in this invention are common knowledge.

[0089] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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.

[0090] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

[0091] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for evaluating the anti-backlight capability of fiber lasers, characterized in that, include: The measurement optical path is constructed, including: a broadband laser source, a tunable bandpass filter, a broadband power amplifier, an optical fiber coupler, an optical fiber wavelength division multiplexer, the fiber laser to be characterized, a laser power / spectral acquisition subsystem, and a data processing unit. The output of the broadband laser source is connected to the input of the tunable bandpass filter, and the output of the tunable bandpass filter is connected to the input of the broadband power amplifier. The broadband laser source obtains a wavelength of [wavelength value missing] through the tunable bandpass filter. λ t The laser, then using a broadband power amplifier to adjust the wavelength to... λ t The laser beam is amplified, wherein the output power of the broadband power amplifier is adjustable; the output end of the broadband power amplifier is connected to the input arm of an optical fiber coupler, and the splitting ratio of the optical fiber coupler is... a :1, the first output arm of the fiber coupler has an output laser ratio of a / ( a The first output arm of the fiber coupler is connected to the fiber wavelength division multiplexer and can transmit laser wavelengths of +1). λ t The second fiber arm; the second output arm of the fiber coupler has an output laser ratio of 1 / ( a The output arm of the +1) fiber optic coupler is connected to the laser power / spectrum acquisition subsystem, which measures its power. P 1; In a fiber optic wavelength division multiplexer, a laser wavelength of [wavelength value missing] can be transmitted. λ t and λ The first fiber arm of the fiber optic cable is connected to the fiber laser to be characterized. The fiber wavelength division multiplexer can transmit lasers with a wavelength of... λ The third fiber arm of the 0 is connected to the laser power / spectrum acquisition subsystem; Obtain the return wavelength of the fiber laser to be characterized in its current operating state. λ t As the return light power increases from a small value, the output power and output spectrum of the fiber laser at different return light powers are analyzed. When calculating different return powers, the effective output power of the fiber laser output laser within the effective operating wavelength range P e ; For effective output power P e By normalizing its maximum value, the effective output power ratio under different backlight powers can be obtained. R e ; Effective output power ratio under different backlight power R e Evaluation of fiber lasers for wavelengths of λ t The strength of anti-backlight capability of lasers with different backlight power.

2. The evaluation method for characterizing the anti-backlight capability of fiber lasers according to claim 1, characterized in that, ... Current backlight power is P i The return power is P i The output power of the fiber laser is P o The output spectrum is I ( λ ); Calculate the backlight power as follows P i At that time, the effective output power of the fiber laser output laser within the effective operating wavelength range P e ,have: in, λ 0 represents the operating wavelength of the fiber laser, and Δ λ This represents the operating bandwidth of the fiber laser.

3. The evaluation method for characterizing the anti-backlight capability of fiber lasers according to claim 2, characterized in that, The return power is P i Effective output power ratio R e ,for: 。 4. The evaluation method for characterizing the anti-backlight capability of fiber lasers according to claim 1, 2, or 3, characterized in that, The return power is P i Effective output power ratio R e The smaller the value, the higher the wavelength. λ t ,power P i The greater the influence of the laser on the fiber laser, the more the fiber laser is affected by wavelengths of [wavelength value missing]. λ t Power is P i The weaker the anti-reflection ability of the laser.

5. An evaluation device for characterizing the anti-backlight capability of a fiber laser, characterized in that, include: The measurement optical path includes: a broadband laser source, a tunable bandpass filter, a broadband power amplifier, an optical fiber coupler, an optical fiber wavelength division multiplexer, the fiber laser to be characterized, a laser power / spectral acquisition subsystem, and a data processing unit. The output of the broadband laser source is connected to the input of the tunable bandpass filter, and the output of the tunable bandpass filter is connected to the input of the broadband power amplifier. The broadband laser source obtains a wavelength of [wavelength value missing] through the tunable bandpass filter. λ t The laser, then using a broadband power amplifier to adjust the wavelength to... λ t The laser beam is amplified, wherein the output power of the broadband power amplifier is adjustable; the output end of the broadband power amplifier is connected to the input arm of an optical fiber coupler, and the splitting ratio of the optical fiber coupler is... a :1, the first output arm of the fiber coupler has an output laser ratio of a / ( a The first output arm of the fiber coupler is connected to the fiber wavelength division multiplexer and can transmit laser wavelengths of +1). λ t The second fiber arm; the second output arm of the fiber coupler has an output laser ratio of 1 / ( a The output arm of the +1) fiber optic coupler is connected to the laser power / spectrum acquisition subsystem, which measures its power. P 1; In a fiber optic wavelength division multiplexer, a laser wavelength of [wavelength value missing] can be transmitted. λ t and λ The first fiber arm of the fiber optic cable is connected to the fiber laser to be characterized. The fiber wavelength division multiplexer can transmit lasers with a wavelength of... λ The third fiber arm of the 0 is connected to the laser power / spectrum acquisition subsystem; The first module is used to obtain the return wavelength of the fiber laser to be characterized in its current operating state. λ t As the return power increases from small to large, the output power and output spectrum of the fiber laser at different return powers are analyzed. The second module is used to calculate the effective output power of the fiber laser output laser within the effective operating wavelength range for different return light powers. P e Let the current backlight power be... P i The return power is P i The output power of the fiber laser is P o The output spectrum is I ( λ ); Calculate the backlight power as follows P i At that time, the effective output power of the fiber laser output laser within the effective operating wavelength range P e ,have: in, λ 0 represents the operating wavelength of the fiber laser, and Δ λ This refers to the operating bandwidth of the fiber laser. The third module is used to measure the effective output power. P e By normalizing its maximum value, the effective output power ratio under different backlight powers can be obtained. R e The backlight power is P i Effective output power ratio R e ,for: The fourth module is used to determine the effective output power ratio based on different backlight powers. R e Evaluation of fiber lasers for wavelengths of λ t The strength of anti-backlight capability of lasers with different backlight power.

6. The evaluation device for characterizing the anti-backlight capability of a fiber laser according to claim 5, characterized in that, In the fourth module, the return power is P i Effective output power ratio R e The smaller the value, the higher the wavelength. λ t ,power P i The greater the influence of the laser on the fiber laser, the more the fiber laser is affected by wavelengths of [wavelength value missing]. λ t Power is P i The weaker the anti-reflection ability of the laser.

7. An evaluation system for characterizing the anti-backlight capability of a fiber laser, implementing the evaluation method for characterizing the anti-backlight capability of a fiber laser as described in claim 1, characterized in that, include: Broadband laser source, tunable bandpass filter, broadband power amplifier, fiber coupler, fiber wavelength division multiplexer, fiber laser to be characterized, laser power / spectral acquisition subsystem, data processing unit; The output of a broadband laser source is connected to the input of a tunable bandpass filter, and the output of the tunable bandpass filter is connected to the input of a broadband power amplifier. The broadband laser source obtains a wavelength of [wavelength value missing] through the tunable bandpass filter. λ t The laser, then using a broadband power amplifier to adjust the wavelength to... λ t The laser beam is amplified, wherein the output power of the broadband power amplifier is adjustable; the output end of the broadband power amplifier is connected to the input arm of an optical fiber coupler, and the splitting ratio of the optical fiber coupler is... a :1, the first output arm of the fiber coupler has an output laser ratio of a / ( a The first output arm of the fiber coupler is connected to the fiber wavelength division multiplexer and can transmit laser wavelengths of +1). λ t The second fiber arm; the second output arm of the fiber coupler has an output laser ratio of 1 / ( a The output arm of the +1) fiber optic coupler is connected to the laser power / spectrum acquisition subsystem, which measures its power. P 1; In a fiber optic wavelength division multiplexer, a laser wavelength of [wavelength value missing] can be transmitted. λ t and λ The first fiber arm of the fiber optic cable is connected to the fiber laser to be characterized. The fiber wavelength division multiplexer can transmit lasers with a wavelength of... λ The third fiber arm of the fiber laser is connected to the laser power / spectrum acquisition subsystem, which measures the output power of the fiber laser to be characterized. P o and output spectrum I ( λ The laser power / spectral acquisition subsystem and data processing module achieve real-time communication and measurement, and the return power injected into the fiber laser to be characterized satisfies... P i = a × P 1.

8. The evaluation system for characterizing the anti-backlight capability of fiber lasers according to claim 7, characterized in that, The fiber laser to be characterized is a fiber oscillator, a superfluorescent fiber laser, a Raman fiber laser, a random fiber laser, or a fiber amplifier.

9. The evaluation system for characterizing the anti-backlight capability of fiber lasers according to claim 7, characterized in that, The operating temperature of the fiber laser to be characterized is any temperature point covering the calibrated operating temperature range of the fiber laser.

10. The evaluation system for characterizing the anti-backlight capability of fiber lasers according to claim 7, characterized in that, By changing the operating parameters of the fiber laser, including operating wavelength, operating power, and / or operating temperature, and altering the return parameters of the laser light entering the fiber laser, including the wavelength and power of the laser light entering the fiber laser, the effective output power ratio of the fiber laser for different wavelengths and powers under different operating conditions can be obtained. R e This allows for a comprehensive evaluation of the anti-backlight capability of fiber lasers.

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