Optical path structure for realizing reference light branching processing of fiber laser

Abstract

The application relates to an optical path structure for realizing reference light branching processing for a fiber laser, wherein the optical path structure comprises: a seed light source for providing signal light for the fiber laser; an optical amplification unit connected with the seed light source, for amplifying the received signal light by absorbing pump light; an optical processing hybrid device connected with the optical amplification unit, for integrated processing of noise removal, light branching and light isolation of the input signal light; a delay optical fiber connected with the optical processing hybrid device, for increasing the optical path difference between the output port of the optical path structure and a reference light port, and the reference light port is connected with the optical processing hybrid device. The optical path structure for realizing reference light branching processing for the fiber laser adopts the integrated TAP+BPF+ISO integrated device to effectively shorten the fiber length, and the BPF filters out the ASE signal, so that the nonlinear effect can be effectively inhibited, and the signal OSNR is increased.

Description

Technical Field

[0001] This invention relates to the field of fiber laser technology, and more particularly to the field of photoelectric detection technology, specifically to an optical path structure for realizing reference light splitting processing of fiber lasers. Background Technology

[0002] Optical detection is widely used due to its advantages such as high detection accuracy, wide detection range, non-contact, and non-destructive operation. Fiber lasers, as the core component of active detection units, play a crucial role. Generally, to monitor and identify whether the laser is working properly and to obtain the time-domain reference value of the laser trigger signal, a portion of the laser outputs a low-power reference light as a monitoring channel. Typically, the output light is split using an independent splitter before being used as the reference light. Due to the time delay requirements of the main signal port and the delay fiber, several meters of delay fiber are usually added at the output end. However, for high-power output main optical ports, this easily causes nonlinear effects, resulting in reduced output power, lower optical signal-to-noise ratio, and unstable output power. Therefore, a monitoring channel design scheme that reduces nonlinear effects is particularly important. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide an optical path structure for reference optical splitting processing of fiber lasers that can effectively suppress nonlinear effects and increase signal OSNR.

[0004] To achieve the above objectives, the optical path structure for reference beam splitting processing of fiber lasers according to the present invention is as follows:

[0005] The main feature of this optical path structure for reference beam splitting processing of fiber lasers is that the optical path structure includes:

[0006] Seed light source, used to provide signal light for fiber lasers;

[0007] An optical amplification unit, connected to the seed light source, is used to amplify the received signal light by absorbing pump light.

[0008] An optical processing hybrid device, connected to the optical amplification unit, is used for integrated processing of the input signal light, including noise reduction, optical splitting, and optical isolation; and

[0009] The delay fiber is connected to the optical processing hybrid device to increase the optical path difference between the output port and the reference optical port of the optical path structure, and the reference optical port is connected to the optical processing hybrid device.

[0010] Preferably, the wavelength range of the signal light is 1500nm to 1600nm.

[0011] Preferably, the optical amplification unit absorbs pump light using forward pumping or reverse pumping, and the optical amplification unit adopts a single-stage amplification structure.

[0012] Preferably, the optical processing hybrid device specifically includes:

[0013] A bandpass filter, connected to the optical amplification unit, is used to denoise the input signal light and filter out the ASE spectrum.

[0014] A splitter, connected to the bandpass filter, is used to reflect a specific ratio of signal light and transmit the remaining portion of the signal light. The reflected signal light is then coupled back into the optical fiber via the bandpass filter for output.

[0015] An optical isolator, connected to the splitter, is used to output the signal light after optical transmission processing and to prevent backlight from entering the optical amplification unit.

[0016] Preferably, the delay fiber, as a transmission fiber, is also connected to the output port of the optical path structure, and is a single-mode fiber or a large-mode-field fiber.

[0017] Preferably, the optical amplification unit absorbs pump light using forward pumping or reverse pumping, and the optical amplification unit adopts a multi-stage amplification structure, with each optical amplification unit connected in series, and the last optical amplification unit in the multi-stage amplification structure is connected to the optical processing hybrid device.

[0018] Preferably, the optical path structure further includes adding multiple BPF filters or ISO isolators + BPF filters at the output port, and each BPF filter or ISO isolator + BPF filter is connected to a delay fiber to suppress the nonlinear effects of the optical path structure and increase the scalable length of the delay fiber.

[0019] Preferably, the optical path structure further includes a control circuit, which is connected to the seed light source and each optical amplification unit respectively. The control circuit has a built-in computer control program for controlling the optical path structure to achieve optical path control.

[0020] The optical path structure for reference beam splitting processing of fiber lasers, as described in this invention, effectively suppresses nonlinear effects using a BPF, greatly improving the output optical power, stability, and signal-to-noise ratio. Furthermore, this design employs a highly integrated hybrid device combining TAP, BPF, and ISO, significantly enhancing the integration and reliability of the equipment. Lasers manufactured based on this design possess the following characteristics: a wide range of selectable optical delays, good beam quality, easy integration, high reliability, and suitability for mass production. Therefore, compared to existing technologies, it has a wider range of applications. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the optical path structure for implementing reference light splitting processing for fiber lasers according to the present invention.

[0022] Figure 2 This is a schematic diagram of the optical path structure for reference light splitting processing of a fiber laser, which employs a multi-stage amplification structure according to the present invention.

[0023] Figure 3 This is a schematic diagram of the structure of the present invention, which adds multiple filters to increase the scalable length of the delay fiber.

[0024] Figure 4 This is a schematic diagram of the optical path structure for reference light splitting processing of fiber lasers according to the present invention, combined with the hardware and software control circuit. Detailed Implementation

[0025] To more clearly describe the technical content of the present invention, the following description is provided in conjunction with specific embodiments.

[0026] Before describing the embodiments of the present invention in detail, it should be noted that, in the following, the terms “comprising,” “including,” or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0027] Please see Figure 1 As shown, this optical path structure for implementing reference light splitting processing for a fiber laser includes:

[0028] Seed light source, used to provide signal light for fiber lasers;

[0029] An optical amplification unit, connected to the seed light source, is used to amplify the received signal light by absorbing pump light.

[0030] An optical processing hybrid device, connected to the optical amplification unit, is used for integrated processing of the input signal light, including noise reduction, optical splitting, and optical isolation; and

[0031] The delay fiber is connected to the optical processing hybrid device to increase the optical path difference between the output port and the reference optical port of the optical path structure, and the reference optical port is connected to the optical processing hybrid device.

[0032] In a preferred embodiment of the present invention, the wavelength range of the signal light is 1500nm to 1600nm.

[0033] In a preferred embodiment of the present invention, the optical amplification unit absorbs pump light by forward pumping or reverse pumping, and the optical amplification unit adopts a single-stage amplification structure.

[0034] In a preferred embodiment of the present invention, the optical processing hybrid device specifically includes:

[0035] A bandpass filter, connected to the optical amplification unit, is used to denoise the input signal light and filter out the ASE spectrum.

[0036] A splitter, connected to the bandpass filter, is used to reflect a specific ratio of signal light and transmit the remaining portion of the signal light. The reflected signal light is then coupled back into the optical fiber via the bandpass filter for output.

[0037] An optical isolator, connected to the splitter, is used to output the signal light after optical transmission processing and to prevent backlight from entering the optical amplification unit.

[0038] In a preferred embodiment of the present invention, the delay fiber is used as a transmission fiber and is also connected to the output port of the optical path structure, and a single-mode fiber or a large-mode-field fiber is used.

[0039] Please see Figure 2 As shown, in a preferred embodiment of the present invention, the optical amplification unit absorbs pump light by forward pumping or reverse pumping, and the optical amplification unit adopts a multi-stage amplification structure, with each optical amplification unit connected in series in sequence, and the last optical amplification unit in the multi-stage amplification structure is connected to the optical processing hybrid device.

[0040] Please see Figure 3As shown, in a preferred embodiment of the present invention, the optical path structure further includes adding multiple BPF filters or ISO isolators + BPF filters at the output port, and each BPF filter or ISO isolator + BPF filter is connected to a delay fiber to suppress the nonlinear effects of the optical path structure and increase the scalable length of the delay fiber.

[0041] Please see Figure 4 As shown, in a preferred embodiment of the present invention, the optical path structure further includes a control circuit, which is connected to the seed light source and each optical amplification unit respectively. The control circuit has a built-in computer control program for controlling the optical path structure to achieve optical path control.

[0042] The implementation method of this technical solution will be further explained in detail below:

[0043] Seed light source: provides signal light for the laser, which can be 1500nm~1600nm;

[0044] Amplification Unit: Fiber laser amplification unit, EYDCF (co-doped double-clad fiber) amplifies the seed source signal by absorbing pump light. This amplification unit can be pumped in either the forward or reverse direction.

[0045] Delay fiber: a transmission fiber used to increase the optical path difference between the output port and the reference optical port; it can be single-mode fiber or large-mode-field fiber.

[0046] Optical processing hybrid device (TAP+BPF+ISO hybrid device): TAP acts as a beam splitter, separating a portion of the output signal as a monitoring signal; BPF is a bandpass filter used to filter out noise signals outside the bandwidth; and ISO is an isolator used to prevent backlight transmission from entering the amplification unit. Its specific operation is as follows:

[0047] The signal light from the input device first undergoes noise reduction processing through a bandpass filter to remove the ASE spectrum. Then, a specific percentage of the signal light is reflected in the beam splitter, while the remaining portion is transmitted. The reflected signal light is then filtered again by a BPF and coupled into the optical fiber for output. The transmitted signal light is then output after passing through an ISO isolator.

[0048] In practical applications, the working principle of this technical solution is as follows:

[0049] The seed light source output signal is amplified and then enters a TAP+BPF+ISO hybrid device. A portion of the high peak power optical signal is used as a monitoring signal. Simultaneously, the signal light is filtered by the BPF, removing noise outside the bandwidth. After passing through an isolator, the signal light enters the delayed fiber output. Due to the high peak power of the amplified signal and the reduction in the nonlinear threshold of the output fiber caused by the added delay, four-wave mixing, self-phase modulation, stimulated Raman, and stimulated Brillouin effects are easily generated, affecting the signal's OSNR and power stability. The BPF filter effectively filters out the equivalent seed light signal with nonlinear effects after removing noise, greatly suppressing nonlinear effects.

[0050] In practical applications, this technical solution employs a TAP+BPF+ISO integrated device at the output end, effectively improving equipment integration, reducing production difficulty, and enhancing equipment reliability. By adding a BPF at the output end to filter the signal, nonlinear effects are significantly suppressed, effectively improving the output optical signal-to-noise ratio, optical-to-optical conversion efficiency, and output optical stability. Furthermore, under the premise of the same output optical power, it effectively increases the length of the delay fiber without causing output optical signal fragmentation. Please refer to [further details omitted]. Figure 1 and Figure 2 As shown, the filtering design scheme using BPF can be applied to both single-stage and multi-stage schemes.

[0051] Please see Figure 3 As shown, this technical solution adds multiple BPF filters or ISO+BPF at the output end to suppress nonlinear effects, which can increase the suppression effect and effectively improve the scalable length of the delay fiber.

[0052] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0053] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution device.

[0054] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0055] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0056] In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0057] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0058] The optical path structure for reference beam splitting processing of fiber lasers, as described in this invention, effectively suppresses nonlinear effects using a BPF, greatly improving the output optical power, stability, and signal-to-noise ratio. Furthermore, this design employs a highly integrated hybrid device combining TAP, BPF, and ISO, significantly enhancing the integration and reliability of the equipment. Lasers manufactured based on this design possess the following characteristics: a wide range of selectable optical delays, good beam quality, easy integration, high reliability, and suitability for mass production. Therefore, compared to existing technologies, it has a wider range of applications.

[0059] In this specification, the invention has been described with reference to specific embodiments thereof. However, it will be apparent that various modifications and variations can be made without departing from the spirit and scope of the invention. Therefore, the specification and drawings should be considered illustrative rather than restrictive.

Claims

1. An optical path structure for reference beam splitting processing of a fiber laser, characterized in that, The optical path structure includes: Seed light source, used to provide signal light for fiber lasers; An optical amplification unit, connected to the seed light source, is used to amplify the received signal light by absorbing pump light. An optical processing hybrid device, connected to the optical amplification unit, is used for integrated processing of the input signal light, including noise reduction, optical splitting, and optical isolation; and A time-delay fiber is connected to the optical processing hybrid device to increase the optical path difference between the output port and the reference optical port of the optical path structure, and the reference optical port is connected to the optical processing hybrid device. The aforementioned optical processing hybrid device specifically includes: A bandpass filter, connected to the optical amplification unit, is used to denoise the input signal light and filter out the ASE spectrum. A splitter, connected to the bandpass filter, is used to reflect a specific ratio of signal light and transmit the remaining portion of the signal light. The reflected signal light is then coupled back into the optical fiber via the bandpass filter for output. An optical isolator, connected to the splitter, is used to output the signal light after optical transmission processing and to prevent backlight from entering the optical amplification unit.

2. The optical path structure for reference beam splitting processing of a fiber laser according to claim 1, characterized in that, The wavelength range of the signal light is 1500nm to 1600nm.

3. The optical path structure for reference beam splitting processing of a fiber laser according to claim 1, characterized in that, The optical amplification unit absorbs pump light using either forward or reverse pumping, and the optical amplification unit employs a single-stage amplification structure.

4. The optical path structure for reference beam splitting processing of a fiber laser according to claim 1, characterized in that, The delay fiber, as a transmission fiber, is also connected to the output port of the optical path structure and is a single-mode fiber or a large-mode-field fiber.

5. The optical path structure for reference beam splitting processing of a fiber laser according to claim 4, characterized in that, The optical amplification unit absorbs pump light using forward or reverse pumping, and the optical amplification unit adopts a multi-stage amplification structure, with each optical amplification unit connected in series, and the last optical amplification unit in the multi-stage amplification structure is connected to the optical processing hybrid device.

6. The optical path structure for reference beam splitting processing of a fiber laser according to claim 5, characterized in that, The optical path structure further includes adding multiple filters or isolators + filters at the output end, and each filter or isolator + filter is connected to a delay fiber to suppress the nonlinear effects of the optical path structure and increase the scalable length of the delay fiber.

7. The optical path structure for reference beam splitting processing of a fiber laser according to claim 5, characterized in that, The optical path structure also includes a control circuit, which is connected to the seed light source and each optical amplification unit. The control circuit has a built-in computer control program for controlling the optical path structure to achieve optical path control.

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