Passive fiber stimulated Brillouin scattering effect threshold adaptive test device

Abstract

The present application discloses a passive fiber stimulated Brillouin scattering effect threshold adaptive test device, which relates to the field of narrow linewidth fiber lasers. The device includes: a laser, a monitoring module and a driving power supply, the driving power supply is respectively connected to the laser and the monitoring module, the laser is respectively connected to the monitoring module and the passive optical fiber, the laser generates a signal laser and transmits it to the passive optical fiber, so that the passive optical fiber reflects the reverse return light to the monitoring module, the driving power supply drives the laser and increases the output power of the laser to a preset first power, the monitoring module monitors the return light power of the reverse return light and determines the stimulated Brillouin scattering threshold value according to the return light power when the return light power is greater than a preset second power, and the monitoring module determines that the passive optical fiber meets the stimulated Brillouin scattering threshold requirement when the stimulated Brillouin scattering threshold value is greater than the preset first power. Compared with manual testing, the present application improves the efficiency of passive optical fiber SBS threshold detection through the above-mentioned determination method.

Description

Technical Field

[0001] The present application relates to the technical field of narrow-linewidth fiber lasers, and in particular to a passive fiber stimulated Brillouin scattering effect threshold adaptive testing device. Background Art

[0002] High-power narrow-linewidth fiber lasers use an all-fiber, integrated, and stable structure that does not require adjustment. They have the advantages of high integration, high conversion efficiency, narrow spectral linewidth, good beam quality, sustainable operation, and good environmental adaptability. They are the preferred light source for advanced laser manufacturing and spectral synthesis. However, the passive fiber performance of the main amplifier in high-power narrow-linewidth fiber lasers is closely related to the threshold of the nonlinear effect (mainly stimulated Brillouin scattering SBS) of the narrow-linewidth fiber laser. Therefore, it is necessary to test the stimulated Brillouin scattering effect threshold of the passive fiber. Testing the stimulated Brillouin threshold of different batches and types of passive fibers requires access to a narrow-linewidth fiber laser for testing, and simultaneously checking the return light power of the narrow-linewidth fiber laser main amplifier to determine whether the stimulated Brillouin scattering threshold has been reached. Passive fibers that meet the stimulated Brillouin scattering threshold requirements are screened out based on the return light power. The passive fiber stimulated Brillouin scattering threshold screening process requires a large investment of manpower and material resources, which seriously affects production efficiency.

[0003] In related technologies, effective solutions have not yet been proposed for the problems of difficulty and low efficiency in screening and detecting the threshold of stimulated Brillouin scattering effect of passive optical fibers used in high-power narrow-linewidth fiber lasers. Summary of the Invention

[0004] The main purpose of this application is to provide a passive fiber stimulated Brillouin scattering effect threshold adaptive test device, which aims to solve the technical problems of difficulty and low efficiency in screening and detecting the threshold of passive fiber stimulated Brillouin scattering effect used in high-power narrow-linewidth fiber lasers.

[0005] To achieve the above-mentioned purpose, the present application proposes a passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device, the passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device comprising: a laser, a monitoring module and a driving power supply;

[0006] The driving power supply is connected to the laser and the monitoring module respectively, and the laser is connected to the monitoring module and the passive optical fiber respectively;

[0007] The laser is used to generate a signal laser and transmit it to the passive optical fiber, so that the passive optical fiber reflects the reverse return light to the monitoring module;

[0008] The driving power supply is used to drive the laser and increase the output power of the laser to a preset first power;

[0009] The monitoring module is used to monitor the return light power of the reverse return light and determine the stimulated Brillouin scattering threshold according to the return light power when the return light power is greater than a preset second power;

[0010] The monitoring module is further configured to determine that the passive optical fiber meets the stimulated Brillouin scattering threshold requirement when the stimulated Brillouin scattering threshold is greater than a preset first power.

[0011] Optionally, the laser includes: a signal source unit and an amplifier module;

[0012] The signal source unit is connected to the driving power supply, the amplifier module and the monitoring module respectively, and the amplifier module is connected to the driving power supply and the monitoring module respectively;

[0013] The signal source unit is used to provide narrow linewidth signal light and transmit it to the amplifier module;

[0014] The amplifier module is used to receive narrow linewidth signal light and transmit reverse return light to the monitoring module.

[0015] Optionally, the amplifier module includes: an optical fiber isolator, a coupler, a pump source and a gain fiber;

[0016] The optical fiber isolator is connected to the monitoring module and the gain fiber respectively, and the coupler is connected to the pump source, the gain fiber, the monitoring module and the passive fiber respectively;

[0017] The pump source is used to provide pump light and transmit it to the coupler;

[0018] The coupler is used to receive the pump light and couple it into the cladding of the gain fiber;

[0019] The gain optical fiber is used to convert the pump light into signal laser and transmit it to the passive optical fiber;

[0020] The optical fiber isolator is used to receive narrow linewidth signal light, isolate the reverse return light and transmit it to the monitoring module.

[0021] Optionally, the amplifier module further comprises: a first optical filter and a second optical filter;

[0022] The first optical filter is connected to the optical fiber isolator, the first optical filter is connected to the coupler via the gain optical fiber, the second optical filter is connected to the coupler, and the monitoring module is connected to the second optical filter and the passive optical fiber respectively;

[0023] The first optical filter is used to filter out the cladding light of the optical fiber cladding when receiving the signal laser;

[0024] The second optical filter is used to filter out the cladding light of the optical fiber cladding when receiving the signal laser.

[0025] Optionally, the amplifier module further comprises: an optical fiber end cap;

[0026] The optical fiber end caps are connected to the passive optical fiber and the monitoring module respectively;

[0027] The gain optical fiber is further used to convert the pump light into a signal laser and transmit it to the optical fiber end cap through the coupler, the second optical filter and the passive optical fiber;

[0028] The optical fiber end cap is used to output the signal laser spatially when receiving the signal laser.

[0029] Optionally, the monitoring module includes: an optical fiber splitter, a photoelectric sensor and a monitoring board;

[0030] The monitoring board is connected to the photoelectric sensor, the amplifier module and the driving power supply respectively, and the optical fiber splitter is connected to the amplifier module;

[0031] The optical fiber beam splitter is used to split the received reverse return light and transmit it to the photoelectric sensor;

[0032] The photoelectric sensor is used to monitor the return light power and feed it back to the monitoring board;

[0033] The monitoring board is configured to determine a stimulated Brillouin scattering threshold value according to the returned light power when the returned light power is received and when the returned light power is greater than a preset second power;

[0034] The monitoring board is further configured to determine that the passive optical fiber meets the stimulated Brillouin scattering threshold requirement when the stimulated Brillouin scattering threshold is greater than a preset first power.

[0035] Optionally, the monitoring module further includes: an infrared detector;

[0036] The infrared detector is connected to the laser;

[0037] The infrared detector is used to detect the status of the fusion points at both ends of the passive optical fiber and send a stop signal to the monitoring board when the fusion point is burned;

[0038] The monitoring board is configured to send a shutdown signal to the driving power supply upon receiving a stop signal;

[0039] The driving power supply is further configured to stop driving the laser when receiving a shutdown signal.

[0040] Optionally, the monitoring module further includes: a spectrometer;

[0041] The spectrometer is connected to the optical fiber beam splitter;

[0042] The optical fiber beam splitter is further used to split the received reverse return light and transmit it to the spectrometer;

[0043] The spectrometer is used to check the spectrum components of the reverse return light spectrum after receiving the reverse return light.

[0044] Optionally, the monitoring module is further configured to determine that stimulated Brillouin scattered light is generated when the return light power is greater than a preset second power.

[0045] Optionally, the monitoring module is further configured to send a shutdown signal to the driving power supply when stimulated Brillouin scattered light is generated;

[0046] The driving power supply is further configured to stop driving the laser when receiving a shutdown signal.

[0047] One or more technical solutions proposed in this application have at least the following effects:

[0048] The present application proposes a passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device, the passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device includes: a laser, a monitoring module and a driving power supply, the driving power supply is respectively connected to the laser and the monitoring module, the laser is respectively connected to the monitoring module and the passive optical fiber, the laser is used to generate a signal laser and transmit it to the passive optical fiber, so that the passive optical fiber reflects the reverse return light to the monitoring module, the driving power supply is used to drive the laser and increase the output power of the laser to a preset first power, the monitoring module is used to monitor the return light power of the reverse return light, and when the return light power is greater than the preset second power, determine the stimulated Brillouin scattering threshold value according to the return light power, the monitoring module is also used to determine that the passive optical fiber meets the stimulated Brillouin scattering threshold requirement when the stimulated Brillouin scattering threshold value is greater than the preset first power. Compared with the manual test of the prior art, the present application improves the passive optical fiber SBS threshold detection efficiency through the above-mentioned determination method, while ensuring the stable operation of the laser, and reducing the manual test cost of passive optical fiber stimulated Brillouin scattering effect threshold screening. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0050] Figure 1 This is a schematic structural diagram of a first embodiment of a passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device proposed in an embodiment of the present application;

[0051] Figure 2 This is a schematic structural diagram of a second embodiment of a passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device proposed in an embodiment of the present application;

[0052] Figure 3 This is a structural schematic diagram of the third embodiment of the passive optical fiber stimulated Brillouin scattering effect threshold adaptive testing device proposed in an embodiment of the present application.

[0053] Description of Figure Numbers:

[0054]

[0055]

[0056] The purpose, features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0057] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not intended to limit the present application.

[0058] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0059] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0060] In addition, the descriptions of "first", "second", etc. in this application are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0061] The main solution of the embodiment of the present application is to determine the passive optical fiber that meets the stimulated Brillouin scattering threshold requirement based on the return light power of the reverse return light.

[0062] The present application provides a solution. The present application proposes a passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device, the passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device comprising: a laser 1, a monitoring module 2 and a driving power supply 3, the driving power supply 3 being connected to the laser 1 and the monitoring module 2 respectively, the laser 1 being connected to the monitoring module 2 and the passive optical fiber respectively, the laser 1 being used to generate a signal laser and transmit it to the passive optical fiber so that the passive optical fiber reflects reverse return light to the monitoring module 2, the driving power supply 3 being used to drive the laser 1 and increase the output power of the laser 1 to a preset first power, the monitoring module 2 being used to monitor the return light power of the reverse return light, and when the return light power is greater than a preset second power, determining the stimulated Brillouin scattering threshold value according to the return light power, the monitoring module 2 being further used to determine that the passive optical fiber meets the stimulated Brillouin scattering threshold requirement when the stimulated Brillouin scattering threshold value is greater than the preset first power. Compared with the manual testing in the prior art, the present application improves the efficiency of passive optical fiber stimulated Brillouin scattering effect threshold detection through the above-mentioned determination method, while ensuring the stable operation of the laser 1, and effectively reducing the manual testing cost of passive optical fiber stimulated Brillouin scattering effect threshold screening.

[0063] Based on this, an embodiment of the present application provides a passive optical fiber stimulated Brillouin scattering effect threshold adaptive testing device.

[0064] refer to Figure 1 , Figure 1 This is a structural schematic diagram of the first embodiment of the passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device proposed in the embodiments of the present application.

[0065] Considering the difficulty and low efficiency of screening and detecting the threshold value of stimulated Brillouin scattering effect of passive optical fiber used in high-power narrow-linewidth fiber laser, the passive optical fiber performance of the main amplifier in high-power narrow-linewidth fiber laser is closely related to the threshold value of nonlinear effect (mainly stimulated Brillouin scattering) of narrow-linewidth fiber laser. In order to improve the detection efficiency of the threshold value of stimulated Brillouin scattering effect of passive optical fiber and ensure the stable operation of laser 1, Figure 1 As shown, the passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device of this embodiment includes: a laser 1, a monitoring module 2 and a driving power supply 3;

[0066] The driving power supply 3 is connected to the laser 1 and the monitoring module 2 respectively, and the laser 1 is connected to the monitoring module 2 and the passive optical fiber respectively;

[0067] The laser 1 is used to generate a signal laser and transmit it to the passive optical fiber, so that the passive optical fiber reflects the backlight to the monitoring module 2;

[0068] The driving power supply 3 is used to drive the laser 1 and increase the output power of the laser 1 to a preset first power;

[0069] The monitoring module 2 is used to monitor the return light power of the reverse return light and determine the stimulated Brillouin scattering threshold according to the return light power when the return light power is greater than a preset second power;

[0070] The monitoring module 2 is further configured to determine that the passive optical fiber meets the stimulated Brillouin scattering threshold requirement when the stimulated Brillouin scattering threshold is greater than a preset first power.

[0071] It should be noted that the stimulated Brillouin scattering effect of passive optical fiber is the SBS effect. The SBS effect is an important nonlinear effect in optical fiber with advantages such as low threshold, extremely narrow linewidth, and high coherence. However, it may also cause energy loss and light source damage to the optical fiber system. Therefore, accurately measuring the threshold of the SBS effect is crucial for optimizing the design and performance of the optical fiber system. The present invention's passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device aims to achieve adaptive testing of the SBS effect threshold to provide accurate measurement results and provide a basis for the design and optimization of optical fiber systems. Passive optical fiber is a fiber optic transmission technology that does not require an external power supply. Passive optical fiber does not have any electrical or optical components and only relies on the reflection and refraction of light to transmit and expand optical signals. This feature means that passive optical fiber does not require the participation of electronic equipment during the transmission process, thereby reducing the complexity and maintenance cost of the system. The working principle of passive optical fiber is mainly based on the principle of total reflection of light. When light is incident on the end face of the optical fiber at a certain angle, if the incident angle is greater than the critical angle, the light will be totally reflected inside the optical fiber and propagate along the optical fiber. The passive optical fiber is the passive optical fiber to be tested, and the passive optical fiber to be tested varies due to different batches and different types. Reverse return light refers to the light reflected back after the light transmitted by the laser 1 touches the surface that is not absorbed. The driving power supply 3 increases the laser output power to a preset first power by loading current, and the monitoring module 2 can automatically control the driving power supply 3 to increase the output power of the laser 1. Reverse return light refers to the phenomenon in a high-power fiber laser system that the return light generated by the laser irradiating the passive optical fiber is recoupled into the inside of the laser 1 and amplified, and the return light power refers to the intensity of the optical signal transmitted by this reverse return light in the optical fiber. In this application, the passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device automatically adjusts the output power of the laser 1 through an adaptive adjustment mechanism according to the monitored SBS scattered light intensity (return light power). When the SBS scattered light intensity reaches the preset threshold condition (preset second power), the pump light power at this time (the output power of the laser 1) is recorded as the threshold of the stimulated Brillouin scattering effect threshold effect. The preset first power can be 1000W or 2000W, and can also be set according to actual conditions. The preset second power can be 1W, and can also be set according to actual conditions.

[0072] In a specific implementation, the laser 1 is used to generate a signal laser and transmit it to the passive optical fiber so that the passive optical fiber reflects reverse return light to the monitoring module 2. The driving power supply 3 is used to drive the laser 1 and increase the output power of the laser 1 to a preset first power. The monitoring module 2 is used to monitor the return light power of the reverse return light, and when the return light power is greater than a preset second power, determine the stimulated Brillouin scattering threshold value according to the return light power. The monitoring module 2 is also used to determine that the passive optical fiber meets the stimulated Brillouin scattering threshold requirement when the stimulated Brillouin scattering threshold value is greater than the preset first power, thereby improving the passive optical fiber stimulated Brillouin scattering effect threshold detection efficiency, while ensuring the stable operation of the laser 1, and effectively reducing the manual testing cost of passive optical fiber stimulated Brillouin scattering effect threshold screening.

[0073] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the first embodiment can be referred to the above introduction and will not be described in detail later. Figure 2 , Figure 2 This is a structural diagram of the second embodiment of the passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device proposed in the embodiment of the present application.

[0074] Considering that the narrow linewidth amplifier amplifies the signal laser through the narrow linewidth signal light, the narrow linewidth characteristics of the signal laser are maintained, such as Figure 2 As shown, the laser 1 of this embodiment includes: a signal source unit 11 and an amplifier module 12;

[0075] The signal source unit 11 is connected to the driving power supply 3, the amplifier module 12 and the monitoring module 2 respectively, and the amplifier module 12 is connected to the driving power supply 3 and the monitoring module 2 respectively;

[0076] The signal source unit 11 is used to provide narrow linewidth signal light and transmit it to the amplifier module 12;

[0077] The amplifier module 12 is configured to receive narrow linewidth signal light and transmit reverse return light to the monitoring module 2 .

[0078] It should be noted that the amplifier module 12 may be a narrow linewidth amplifier, which amplifies the signal laser through the narrow linewidth signal light to maintain the narrow linewidth characteristic of the signal laser.

[0079] In a specific implementation, the signal source unit 11 is used to provide narrow linewidth signal light and transmit it to the amplifier module 12. The amplifier module 12 is used to receive the narrow linewidth signal light and transmit the reverse return light to the monitoring module 2, thereby determining the passive optical fiber that meets the stimulated Brillouin scattering threshold requirements through the return light power of the reverse return light.

[0080] Based on the second embodiment of the present application, in the third embodiment of the present application, the same or similar contents as those in the second embodiment can be referred to the above introduction and will not be described in detail later. Figure 3 , Figure 3 This is a structural schematic diagram of the third embodiment of the passive optical fiber stimulated Brillouin scattering effect threshold adaptive testing device proposed in an embodiment of the present application.

[0081] Considering that the passive optical fiber that meets the stimulated Brillouin scattering threshold requirement is determined according to the return power of the reverse return light, and then in order to isolate the reverse return light through the optical fiber isolator 121, as shown in FIG. Figure 3 As shown, the amplifier module 12 of this embodiment includes: a fiber isolator 121, a coupler 122, a pump source 123 and a gain fiber 124;

[0082] The optical fiber isolator 121 is connected to the monitoring module 2 and the gain fiber 124 respectively, and the coupler 122 is connected to the pump source 123, the gain fiber 124, the monitoring module 2 and the passive fiber respectively;

[0083] The pump source 123 is used to provide pump light and transmit it to the coupler 122;

[0084] The coupler 122 is used to receive the pump light and couple it into the cladding of the gain fiber 124;

[0085] The gain fiber 124 is used to convert the pump light into a signal laser and transmit it to the passive optical fiber;

[0086] The optical fiber isolator 121 is used to receive narrow linewidth signal light, isolate the reverse return light and transmit it to the monitoring module 2.

[0087] It should be noted that the optical fiber isolator 121 is a high-power three-port circulator, which is used to transmit higher-power forward seed laser and isolate reverse return light. The forward seed laser can be a narrow-linewidth signal light. The gain fiber 124 is an ytterbium-doped optical fiber, which uses a bending and winding method to lose high-order modes. The gain fiber 124 converts the pump light into a signal laser to achieve high-gain laser amplification without mode instability. The pump source 123 can be a pump source 123 group composed of multiple pump sources 123. The coupler 122 is a pump / signal coupler 122, and the pump / signal coupler 122 is a low insertion loss coupler 122. The pump source 123 provides high-power pump light for the gain fiber 124. The passive optical fiber is an optical fiber sample used to test the stimulated Brillouin scattering threshold.

[0088] In a specific implementation, the pump source 123 is used to provide pump light and transmit it to the coupler 122. The coupler 122 is used to receive the pump light and couple it into the cladding of the gain fiber 124. The gain fiber 124 is used to convert the pump light into a signal laser and transmit it to the passive optical fiber. The optical fiber isolator 121 is used to receive the narrow linewidth signal light, isolate the reverse return light and transmit it to the monitoring module 2, so as to determine the passive optical fiber that meets the stimulated Brillouin scattering threshold requirements through the return light power of the reverse return light.

[0089] Furthermore, the amplifier module 12 further includes: a first optical filter 125 and a second optical filter 126;

[0090] The first optical filter 125 is connected to the optical fiber isolator 121, the first optical filter 125 is connected to the coupler 122 via the gain optical fiber 124, the second optical filter 126 is connected to the coupler 122, and the monitoring module 2 is connected to the second optical filter 126 and the passive optical fiber respectively;

[0091] The first optical filter 125 is used to filter out the cladding light of the optical fiber cladding when receiving the signal laser;

[0092] The second optical filter 126 is used to filter out the cladding light of the optical fiber cladding when receiving the signal laser.

[0093] It should be noted that the first optical filter 125 and the second optical filter 126 can also improve the quality of the signal laser beam. The fusion joint between the optical fiber isolator 121 and the first optical filter 125 is cured with high-refractive index glue. The fusion joints between the first optical filter 125, the gain fiber 124, the coupler 122, the passive optical fiber, and the optical fiber end cap 127 are all coated with low-refractive index glue. The fusion joint between the coupler 122 and the pump source 123 is cured with high-refractive index glue. There is no fusion joint on the connecting optical fiber between the coupler 122 and the second optical filter 126.

[0094] It can be understood that the cladding light is the redundant signal laser and pump light.

[0095] In a specific implementation, the first optical filter 125 is used to filter out the cladding light of the optical fiber cladding when receiving the signal laser, and the second optical filter 126 is used to filter out the cladding light of the optical fiber cladding and improve the signal laser beam quality when receiving the signal laser.

[0096] Furthermore, the amplifier module 12 further includes: an optical fiber end cap 127;

[0097] The optical fiber end cap 127 is connected to the passive optical fiber and the monitoring module 2 respectively;

[0098] The gain fiber 124 is further used to convert the pump light into a signal laser and transmit it to the fiber end cap 127 through the coupler 122, the second optical filter 126 and the passive optical fiber;

[0099] The optical fiber end cap 127 is used to output the signal laser spatially when receiving the signal laser.

[0100] It should be noted that the fiber end cap 127 is a plastic film or metal cover used to protect the fiber connector. Its primary function is to prevent contaminants such as dust and moisture from entering the connector, thereby ensuring the quality and service life of the fiber connection. Furthermore, for high-power fiber lasers and amplifiers, the fiber end cap 127 also reduces the optical power density at the output end and reduces end-face echo reflections.

[0101] In a specific implementation, the optical fiber end cap 127 is used to output the signal laser spatially when receiving the signal laser.

[0102] Furthermore, the monitoring module 2 includes: an optical fiber splitter 21, a photoelectric sensor 22 and a monitoring board 23;

[0103] The monitoring board 23 is connected to the photoelectric sensor 22, the amplifier module 12 and the driving power supply 3 respectively, and the optical fiber splitter 21 is connected to the amplifier module 12;

[0104] The optical fiber beam splitter 21 is used to split the received reverse return light and transmit it to the photoelectric sensor 22;

[0105] The photoelectric sensor 22 is used to monitor the return light power and feed it back to the monitoring board 23;

[0106] The monitoring board 23 is configured to determine a stimulated Brillouin scattering threshold value based on the returned light power when the returned light power is received and when the returned light power is greater than a preset second power;

[0107] The monitoring board 23 is further configured to determine that the passive optical fiber meets the stimulated Brillouin scattering threshold requirement when the stimulated Brillouin scattering threshold is greater than a preset first power.

[0108] It should be noted that the photoelectric sensor 22 may be a photodiode, and the photodiode may be a pigtailed type.

[0109] In a specific implementation, the optical fiber splitter 21 is used to split the reverse return light upon receipt and transmit it to the photoelectric sensor 22. The photoelectric sensor 22 is used to monitor the return light power of the reverse return light and feed it back to the monitoring board 23. The monitoring board 23 is used to determine the stimulated Brillouin scattering threshold based on the return light power when the return light power is received and when the return light power is greater than a preset second power. The monitoring board 23 is also used to determine that the passive optical fiber meets the stimulated Brillouin scattering threshold requirement when the stimulated Brillouin scattering threshold is greater than a preset first power, thereby improving the threshold detection efficiency of the stimulated Brillouin scattering effect of the passive optical fiber.

[0110] Furthermore, the monitoring module 2 further includes: an infrared detector;

[0111] The infrared detector is connected to the laser 1;

[0112] The infrared detector is used to detect the status of the fusion points at both ends of the passive optical fiber and send a stop signal to the monitoring board 23 when the fusion point is burned;

[0113] The monitoring board 23 is used to send a shutdown signal to the driving power supply 3 when receiving a stop signal;

[0114] The driving power supply 3 is further configured to stop driving the laser 1 upon receiving a shutdown signal.

[0115] It should be noted that once the welding point is burned, the infrared detector will detect scattered light. The infrared detector can be a near-infrared detector. The stop signal and the shutdown signal can be voltage signals or current signals. They can also be set according to actual conditions. This embodiment does not limit this.

[0116] In a specific implementation, the infrared detector is used to detect the status of the fusion points at both ends of the passive optical fiber, and when the fusion point is burned, sends a stop signal to the monitoring board 23. The monitoring board 23 is used to send a shutdown signal to the driving power supply 3 when receiving the stop signal. The driving power supply 3 is also used to stop driving the laser 1 when receiving the shutdown signal, thereby improving the threshold detection efficiency of the stimulated Brillouin scattering effect of the passive optical fiber and ensuring the stable operation of the laser 1.

[0117] Furthermore, the monitoring module 2 further includes: a spectrometer;

[0118] The spectrometer is connected to the optical fiber beam splitter 21;

[0119] The optical fiber beam splitter 21 is further used to split the received reverse return light and transmit it to the spectrometer;

[0120] The spectrometer is used to check the spectrum components of the reverse return light spectrum after receiving the reverse return light.

[0121] It should be noted that the port used to connect to the spectrometer is a reserved detection port, and you can also connect to the detection equipment yourself according to actual conditions.

[0122] Furthermore, the monitoring module 2 is further configured to determine that stimulated Brillouin scattered light is generated when the return light power is greater than a preset second power.

[0123] It should be noted that the passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device in the present application automatically adjusts the output power of the laser 1 through an adaptive adjustment mechanism according to the changes in the monitored SBS scattered light intensity (return light power). When the SBS scattered light intensity reaches a preset threshold condition (preset second power), the pump light power at this time (the output power of the laser 1) is recorded as the threshold of the stimulated Brillouin scattering effect threshold effect.

[0124] In a specific implementation, the monitoring module 2 is further configured to determine that stimulated Brillouin scattering light is generated when the return light power is greater than a preset second power, thereby improving the threshold detection efficiency of the stimulated Brillouin scattering effect of the passive optical fiber.

[0125] Furthermore, the monitoring module 2 is further configured to send a shutdown signal to the driving power supply 3 when stimulated Brillouin scattered light is generated;

[0126] The driving power supply 3 is further configured to stop driving the laser 1 upon receiving a shutdown signal.

[0127] In a specific implementation, the monitoring module 2 is also used to send a shutdown signal to the driving power supply 3 when stimulated Brillouin scattering light is generated. The driving power supply 3 is also used to stop driving the laser 1 when receiving the shutdown signal, thereby improving the threshold detection efficiency of the passive optical fiber stimulated Brillouin scattering effect and ensuring the stable operation of the laser 1.

[0128] It should be noted that if Figure 3As shown, in the embodiment, the signal source unit 11 outputs 50W, 0.2nm narrow linewidth seed laser (narrow linewidth signal light), the optical fiber isolator 121, the first optical filter 125, the gain fiber 124, the coupler 122, the second optical filter 126, the (to be measured) passive optical fiber and the signal optical fiber of the optical fiber end cap 127 all adopt an optical fiber with a core numerical aperture of 0.065, a core diameter of 20μm and a cladding diameter of 400μm; the pump source 123 outputs a pump light wavelength of 976nm, the cladding pump absorption coefficient of the gain optical fiber 124 is 1.2dB / m@976nm, and the optical fiber length is set to 15m; the optical fiber lengths of the passive optical fiber and the optical fiber end cap 127 are set to 1m and 1m respectively; after turning on the laser 1, The driving power supply 3 automatically and gradually loads current to increase the laser output power to a preset current. At this time, the laser power is 1000W (preset first power). When the stimulated Brillouin threshold is ≥1000W, it is determined that the stimulated Brillouin threshold of this batch of passive optical fibers to be tested meets the requirements; when the return light power of the optical fiber isolator 121 is ≥1W (preset second power), it is determined that obvious stimulated Brillouin scattered light is generated, and the laser 1 is automatically turned off; three batches of passive optical fibers to be tested (batch 1, batch 2, batch 3) were tested, and the stimulated Brillouin scattering thresholds were ≥1000W, ≥1000W, and 800W, respectively. It is determined that the stimulated Brillouin scattering thresholds of batches 1 and 2 meet the requirements, and the stimulated Brillouin scattering threshold of batch 3 does not meet the requirements.

[0129] It should be noted that, in the embodiment, the signal source unit 11 outputs 50W 0.2nm narrow linewidth seed laser (narrow linewidth signal light), the optical fiber isolator 121, the first optical filter 125, the gain fiber 124, the coupler 122, the second optical filter 126, the (to be measured) passive optical fiber and the signal optical fiber of the optical fiber end cap 127 all adopt an optical fiber with a core numerical aperture of 0.065, a core diameter of 25μm and a cladding diameter of 400μm; the pump source 123 outputs a pump light wavelength of 976nm, the cladding pump absorption coefficient of the gain optical fiber 124 is 1.5dB / m@976nm, and the optical fiber length is set to 12m; the optical fiber lengths of the passive optical fiber to be measured and the optical fiber end cap 127 are set to 1m and 1m respectively; the laser 1 is turned on. Afterwards, the driving power supply 3 automatically and gradually loads current to increase the laser output power to the preset current. At this time, the laser output power is 2000W (preset first power). When the stimulated Brillouin threshold is ≥2000W, it is determined that the stimulated Brillouin threshold of this batch of passive optical fibers meets the requirements; when the return light power of the optical fiber isolator 121 is ≥1W (preset second power), it is determined that obvious stimulated Brillouin scattering light is generated, and the laser 1 is turned off; 3 batches of passive optical fibers to be tested (batch 1, batch 2, batch 3) are tested, and the stimulated Brillouin scattering thresholds are ≥2000W, ≥2000W, and 1700W, respectively. It is judged that the stimulated Brillouin scattering thresholds of batches 1 and 2 meet the requirements, and the stimulated Brillouin scattering threshold of batch 3 does not meet the requirements.

[0130] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device, characterized in that: The passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device includes: a laser, a monitoring module and a driving power supply; The driving power supply is connected to the laser and the monitoring module respectively, and the laser is connected to the monitoring module and the passive optical fiber respectively; A laser, used to generate a signal laser and transmit it to a passive optical fiber, so that the passive optical fiber reflects back light to the monitoring module; A driving power supply, used to drive the laser and increase the output power of the laser to a preset first power; a monitoring module, configured to monitor the return light power of the reverse return light and, when the return light power is greater than a preset second power, determine a stimulated Brillouin scattering threshold value based on the return light power; The monitoring module is further configured to determine that the passive optical fiber meets the stimulated Brillouin scattering threshold requirement when the stimulated Brillouin scattering threshold is greater than a preset first power; The laser includes: a signal source unit and an amplifier module; The signal source unit is connected to the driving power supply, the amplifier module and the monitoring module respectively, and the amplifier module is connected to the driving power supply and the monitoring module respectively; A signal source unit, used for providing narrow linewidth signal light and transmitting it to the amplifier module; An amplifier module is used to receive narrow linewidth signal light and transmit reverse return light to the monitoring module; The amplifier module includes: fiber isolator, coupler, pump source and gain fiber; The optical fiber isolator is connected to the monitoring module and the gain fiber respectively, and the coupler is connected to the pump source, the gain fiber, the monitoring module and the passive fiber respectively; A pump source, used to provide pump light and transmit it to the coupler; a coupler for receiving the pump light and coupling it into the cladding of the gain fiber; Gain fiber, used to convert pump light into signal laser and transmit it to passive optical fiber; Fiber optic isolator, used to receive narrow linewidth signal light, isolate the reverse return light and transmit it to the monitoring module; The monitoring module includes: optical fiber splitter, photoelectric sensor and monitoring board; The monitoring board is connected to the photoelectric sensor, the amplifier module and the driving power supply respectively, and the optical fiber splitter is connected to the amplifier module; A fiber optic beam splitter is used to split the received return light and transmit it to the photoelectric sensor; Photoelectric sensor, used to monitor the return light power and feed it back to the monitoring board; The monitoring board is used to determine a stimulated Brillouin scattering threshold according to the returned light power when the returned light power is received and when the returned light power is greater than a preset second power.

2. The passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device according to claim 1, characterized in that: The amplifier module further includes: a first optical filter and a second optical filter; The first optical filter is connected to the optical fiber isolator, the first optical filter is connected to the coupler via the gain optical fiber, the second optical filter is connected to the coupler, and the monitoring module is connected to the second optical filter and the passive optical fiber respectively; The first optical filter is used to filter out the cladding light of the optical fiber cladding when receiving the signal laser; The second optical filter is used to filter out the cladding light of the optical fiber cladding when receiving the signal laser.

3. The passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device according to claim 2, characterized in that: The amplifier module further includes: an optical fiber end cap; The optical fiber end caps are connected to the passive optical fiber and the monitoring module respectively; The gain optical fiber is further used to convert the pump light into a signal laser and transmit it to the optical fiber end cap through the coupler, the second optical filter and the passive optical fiber; The optical fiber end cap is used to output the signal laser spatially when receiving the signal laser.

4. The passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device according to claim 1, characterized in that: The monitoring board is further configured to determine that the passive optical fiber meets the stimulated Brillouin scattering threshold requirement when the stimulated Brillouin scattering threshold is greater than a preset first power.

5. The passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device according to claim 4, characterized in that: The monitoring module further includes: an infrared detector; The infrared detector is connected to the laser; The infrared detector is used to detect the status of the fusion points at both ends of the passive optical fiber and send a stop signal to the monitoring board when the fusion point is burned; The monitoring board is configured to send a shutdown signal to the driving power supply upon receiving a stop signal; The driving power supply is further configured to stop driving the laser when receiving a shutdown signal.

6. The passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device according to claim 4, characterized in that: The monitoring module further includes: a spectrometer; The spectrometer is connected to the optical fiber beam splitter; The optical fiber beam splitter is further used to split the received reverse return light and transmit it to the spectrometer; The spectrometer is used to check the spectrum components of the reverse return light spectrum after receiving the reverse return light.

7. The passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device according to claim 1, characterized in that: The monitoring module is further configured to determine that stimulated Brillouin scattered light is generated when the return light power is greater than a preset second power.

8. The passive optical fiber stimulated Brillouin scattering effect threshold adaptive test device according to claim 7, characterized in that: The monitoring module is further configured to send a shutdown signal to the driving power supply when stimulated Brillouin scattered light is generated; The driving power supply is further configured to stop driving the laser when receiving a shutdown signal.

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