Fiber laser and coupling method thereof

Abstract

The present application relates to a kind of fiber lasers, including shell, signal transmitting chip and pump chip, signal transmitting chip and pump chip are coupled and packaged in shell, shell is connected with light output fiber and collimating rare earth doped amplification optical fiber, collimating rare earth doped amplification optical fiber is communicated with Faraday rotator mirror;Signal light exported by signal transmitting chip is handled by first optical path component, first by collimating rare earth doped amplification optical fiber input Faraday rotator mirror, then return to the output of light output fiber after shell;Pump light signal exported by pump chip is handled by second optical path component and then input collimating rare earth doped amplification optical fiber.A kind of coupling method of fiber laser is also provided.The present application only has this one welding point between collimating rare earth doped amplification optical fiber and Faraday rotator mirror, reduces welding loss;Signal chip and pump chip are directly coupled and packaged in the same shell by space optical path, provide directly usable fiber laser finished product scheme, it is convenient to use small and exquisite.

Description

Technical Field

[0001] This invention relates to the field of optical communication technology, specifically to a fiber laser and its coupling method. Background Technology

[0002] Existing fiber-optic amplified lasers typically employ various functional components with pigtails, spliced ​​together to form a fiber optic amplification system. This involves splicing individual laser / signal transmitters, pump sources, multiplexers / beam combiners, and isolators with collimated rare-earth-doped amplifying fibers. Each connection introduces a new splice point, resulting in numerous splice points and significant splice loss (approximately 0.2 dB loss per splice). The assembly process is complex and inconvenient. Furthermore, each functional component requires a long pigtail for splicing, both for ease of operation and to allow sufficient length for coiling to ensure system stability. However, the long fiber transmission path itself introduces transmission loss and can lead to nonlinear issues, resulting in limited transmission coupling efficiency in existing fiber-optic amplified laser systems. Summary of the Invention

[0003] The purpose of this invention is to provide a fiber laser and its coupling method, which can at least solve some of the defects in the prior art.

[0004] To achieve the above objectives, embodiments of the present invention provide the following technical solution: a fiber laser, comprising a housing, a signal emitting chip, and a pump chip, wherein the signal emitting chip and the pump chip are both coupled and encapsulated within the housing, the housing is connected to an output fiber and a collimating rare-earth-doped amplifying fiber, and the collimating rare-earth-doped amplifying fiber is connected to a Faraday rotator mirror; the signal light output by the signal emitting chip is processed by a first optical path component, first input into the Faraday rotator mirror via the collimating rare-earth-doped amplifying fiber, and then returns to the housing before being output by the output fiber; the pump light signal output by the pump chip is processed by a second optical path component and then input into the collimating rare-earth-doped amplifying fiber.

[0005] Furthermore, the first optical path component includes a first collimating lens, a first polarization isolator, a PBS polarization beam splitter, a filter, and a beam combiner. The signal light output by the signal transmitting chip passes sequentially through the first collimating lens, the first polarization isolator, the PBS polarization beam splitter, the filter, and the beam combiner before entering the collimated rare-earth-doped amplifying fiber.

[0006] Furthermore, the first optical path component also includes a second polarization isolator, and the signal light returning to the housing passes sequentially through the beam combiner prism, the filter, and the second polarization isolator before entering the output optical fiber.

[0007] Furthermore, the housing has a first mounting area and a second mounting area arranged side by side, the signal transmitting chip is located in the first mounting area, and the pump chip is located in the second mounting area.

[0008] Furthermore, the second mounting area has a stepped structure, and the direction from the higher platform to the lower platform of the stepped structure is consistent with the direction of the pump light output of the pump chip.

[0009] Furthermore, an insulating heat pipe is provided between the first installation area and the second installation area.

[0010] This invention provides another technical solution: a coupling method for the above-mentioned fiber laser, characterized by comprising the following steps:

[0011] S1, the signal transmitting chip and the pump chip are mounted on the housing at a preset position;

[0012] S2, the pump optical path of the pump chip is coupled;

[0013] S3, then the signal optical path of the signal transmitting chip is coupled;

[0014] S4, continue coupling the output optical fiber;

[0015] S5, finally, the second collimating lens is coupled. The second collimating lens is used to collimate the signal light processed by the first optical path component and output it to the light-emitting optical fiber.

[0016] Furthermore, in step S1, the first polarization isolator, the second polarization isolator, the filter, and the wave combiner prism are also attached to the predetermined positions of the housing, specifically:

[0017] The signal transmitting chip is first fixed in a preset position using the central axis of the optical output port of the housing and the side wall of the housing as positioning references;

[0018] The first polarization isolator is fixed in a preset position with the light-emitting strip of the signal transmitting chip as the positioning reference;

[0019] The second polarization isolator is fixed in a preset position with the side wall of the housing as the positioning reference;

[0020] The pump chip is fixed in a preset position with the rare earth-doped optical fiber inlet center axis of the housing and the side wall of the housing as positioning references.

[0021] The wave-combining prism is fixed in a preset position using the light-emitting strip of the pump chip and the edge of the pump chip as positioning references.

[0022] The filter is fixed in a preset position using the wave-combining prism and the side wall of the housing as positioning references.

[0023] Furthermore, the coupling method in step S2 is specifically as follows:

[0024] S20, the tail end of the collimated rare-earth-doped amplifying fiber is connected to the optical power meter via fusion splicing.

[0025] S21, Power on the pump chip.

[0026] S22, Move the position of the collimated rare-earth-doped amplifying fiber relative to the collimated rare-earth-doped amplifying fiber inlet of the housing.

[0027] S23, observe the reading of the optical power meter until the position that maximizes the optical power meter reading is found, record the value, and fix the collimating rare-earth-doped amplifying fiber at the corresponding position on the housing.

[0028] S24, place the fast-axis shaping prism in a preset initial position, power on the pump chip, move the fast-axis shaping prism, observe the reading of the optical power meter until the maximum reading of the optical power meter is found, record the reading, and fix the fast-axis shaping prism in the corresponding position on the housing.

[0029] S25, place the slow-axis shaping prism in a preset initial position, power on the pump chip, move the slow-axis shaping prism, observe the reading of the optical power meter until the maximum reading of the optical power meter is found, record it, and fix the slow-axis shaping prism in the corresponding position of the housing.

[0030] Furthermore, the coupling method in step S3 is specifically as follows:

[0031] S30, using a first collimating lens and a PBS polarizing beam splitter, with the light-emitting strip of the signal transmitting chip as the positioning reference, is placed in a first preset initial position;

[0032] S31, Power on the signal transmitting chip and observe the optical power reading of the collimated rare-earth-doped amplifying fiber tail splice.

[0033] S32, Move the position of the first collimating lens to find the position of the first collimating lens when the PBS polarizing beam splitter is placed in the first preset initial position, and record the position of the first collimating lens and the first maximum value of the optical power meter at this time;

[0034] S33, move the position of the PBS polarizing beam splitter mirror with a certain motion logic, and then readjust the position of the first collimating lens until the reading of the optical power meter reaches the new second maximum value under the current position of the first collimating lens. Record the current position of the first collimating lens and the second maximum value of the optical power meter.

[0035] S34, compare the first maximum value and the second maximum value to determine the subsequent motion direction of the PBS polarizing beam-splitting mirror;

[0036] S35, after the PBS polarizing beam-splitting mirror is moved, the first collimating lens is adjusted again to obtain the maximum power value;

[0037] S36, Repeat the above operation until the optimal matching position of the first collimating lens and the PBS polarizing beam splitter is found that maximizes the power value, and record the position of the first collimating lens and the position of the PBS polarizing beam splitter respectively.

[0038] S37, then keep the positions of the first collimating lens 31 and the PBS polarizing beam splitter 51 unchanged; with the axis extending in the direction of the signal light output by the signal transmitting chip 2 as the rotation center axis, rotate the PBS polarizing beam splitter 51 around the rotation center axis to finely adjust the angle of the PBS polarizing beam splitter 51 until the reading of the optical power meter reaches the maximum value and then stop.

[0039] Compared with the prior art, the beneficial effects of the present invention are:

[0040] 1. With only one fusion splice point between the collimating rare-earth-doped amplifying fiber and the Faraday rotating mirror, fusion loss is reduced. The signal chip and pump chip are directly coupled and packaged in the same housing through a spatial optical path, providing a ready-to-use fiber laser solution. Unlike existing solutions that use separate signal transmitting devices, pump devices, collimating rare-earth-doped amplifying fibers, and multiplexers, which require additional fusion splicing as needed, this solution is convenient to use and compact in size, making it suitable for applications with high space requirements, such as lidar or vehicle radar systems.

[0041] 2. By using the first and second optical path components to process the optical signal, spatial optical transmission is achieved, eliminating the need for optical fibers connecting various components and retaining only the output optical fiber and the collimating rare-earth-doped amplification optical fiber. By eliminating the connecting optical fibers, the nonlinearity problems caused by long optical fiber transmission paths and the transmission loss generated by optical fiber transmission itself are avoided, which can effectively improve coupling efficiency. Moreover, by eliminating the connecting optical fibers, the space required for fiber coiling between various components is greatly saved, which can improve integration and significantly reduce product size. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the structure of a fiber laser provided in an embodiment of the present invention;

[0043] Figure 2 for Figure 1 Enlarged schematic diagram of the casing;

[0044] Figure 3 This is a schematic diagram of the structure of a housing and a gold finger connector for a fiber laser provided in an embodiment of the present invention;

[0045] In the attached diagram, the following labels are used: 1-Housing; 11-Gold finger connector; 12-Optical output port; 13-Collimating rare-earth-doped amplifying fiber optic inlet; 14-First mounting area; 15-Second mounting area; 16-Insulation heat pipe; 2-Signal transmitting chip; 31-First collimating lens; 32-Fast axis shaping prism; 33-Slow axis shaping prism; 34-Second collimating lens; 41-First polarization isolator; 42-Second polarization isolator; 51-PBS polarization beam splitter; 511-Brightness splitting medium; 512-Reflecting surface; 52-Filter; 53-Brightness combining prism; 6-Pump chip; 71-Emitting fiber; 72-Collimating rare-earth-doped amplifying fiber; 711-Connector; 8-Faraday rotator; 9-TEC; 91-Cold surface. Detailed Implementation

[0046] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Example 1:

[0048] Please see Figure 1 , Figure 2 and Figure 3This invention provides a fiber laser, including a housing 1, a signal emitting chip 2, and a pump chip 6. The signal emitting chip 2 and the pump chip 6 are both coupled and encapsulated within the housing 1. The housing 1 is connected to an output fiber 71 and a collimating rare-earth-doped amplifying fiber 72. The collimating rare-earth-doped amplifying fiber 72 is connected to a Faraday rotator mirror 8. The signal light output from the signal emitting chip 2 is processed by a first optical path component, first input to the Faraday rotator mirror 8 via the collimating rare-earth-doped amplifying fiber 72, and then returns to the housing 1 before being output from the output fiber 71. The pump light signal output from the pump chip 6 is processed by a second optical path component and then input to the collimating rare-earth-doped amplifying fiber 72. In this embodiment, the fiber laser has only one splice point between the collimating rare-earth-doped amplifying fiber 72 and the Faraday rotating mirror, which reduces splice loss. The signal chip and pump chip 6 are directly coupled and packaged in the same housing 1 through a spatial optical path, providing a ready-to-use fiber laser solution. Unlike existing solutions that use separate signal transmitting devices, pump devices, collimating rare-earth-doped amplifying fibers 72, and multiplexers, which require additional splicing and assembly according to requirements, this solution is convenient to use and compact in size, making it suitable for applications with high space requirements, such as lidar or vehicle radar systems. Specifically, the signal transmitting chip 2 and the pump chip 6 are both housed in the same housing 1. There are two optical paths in the housing 1: one is the signal optical path of the signal transmitting chip 2, and the other is the pump optical path of the pump chip 6. After the signal light is output from the signal transmitting chip 2, it is processed by the first optical path component and first enters the collimated rare-earth-doped amplifying fiber 72. Then it is reflected back by the Faraday rotator mirror 8 at the end of the collimated rare-earth-doped amplifying fiber 72 and finally enters the output optical fiber 71. The pump light is processed by the second optical path component and then input into the collimated rare-earth-doped amplifying fiber 72.

[0049] As an optimized solution for an embodiment of the present invention, please refer to Figure 1 , Figure 2 and Figure 3The first optical path assembly includes a first collimating lens 31, a first polarization isolator 41, a PBS polarization beam splitter 51, a filter 52, and a beam combiner 53. The signal light output from the signal transmitting chip 2 passes sequentially through the first collimating lens 31, the first polarization isolator 41, the PBS polarization beam splitter 51, the filter 52, and the beam combiner 53 before entering the collimated rare-earth-doped amplifying fiber 72. The first optical path assembly also includes a second polarization isolator 42. The signal light returning to the housing 1 passes sequentially through the beam combiner 53, the filter 52, and the second polarization isolator 42 before entering the output fiber 71. In this embodiment, the first polarization isolator 41 is used to process the light emitted by the signal transmitting chip 2 into mostly S-polarized light (including a very small portion of P-polarized light) (S-polarized light here refers to light with a polarization direction perpendicular to the incident plane, and P-polarized light refers to light with a polarization direction parallel to the incident plane), while preventing reflected light from returning to the signal transmitting chip 2, thereby affecting the light emission performance of the signal transmitting chip 2. The PBS polarization beam splitter 51 includes a beam splitting medium 511 for reflecting S-polarized light and transmitting P-polarized light, and a reflecting surface 512 for reflecting signal light. The Faraday rotator 8 is used to rotate the S-polarized signal light into P-polarized signal light and reflect and refract it to transmit the amplified signal light back. Specifically, the signal light emitted by the signal transmitting chip 2 is first collimated into parallel light by the first collimating lens 31, and then processed into S-polarized light (containing a very small portion of P-polarized light) by the first polarization isolator 41. The P-polarized light is dissipated directly through the PBS polarization beam splitter 51, while the S-polarized light is reflected by the beam splitting medium 511 of the PBS polarization beam splitter 51, filtered by the filter 52, and reflected by the wave combiner prism 53 into the collimating rare-earth-doped amplifying fiber 72 for amplification. It is then rotated and reflected by the Faraday rotator 8 into P-polarized light and transmitted back in the opposite direction. After passing through the collimating rare-earth-doped amplifying fiber 72 again, reflected by the wave combiner prism 53, and filtered by the filter 52, it passes through the beam splitting medium 511 of the PBS polarization beam splitter 51, and is reflected by the reflecting surface 512 of the PBS polarization beam splitter 51. It is then output through the output fiber 71 after passing through the second polarization isolator 42 (and the second collimating lens 34).

[0050] As an optimized solution for an embodiment of the present invention, please refer to Figure 1 , Figure 2 and Figure 3The second optical path component includes a fast-axis shaping prism 32 and a slow-axis shaping prism 33. The pump light emitted by the pump chip 6 passes sequentially through the fast-axis shaping prism 32 and the slow-axis shaping prism 33, and then enters the collimated rare-earth-doped amplifying fiber 72 through the wave combiner prism 53. In this embodiment, the pump chip 6 emits pump light. Due to the structure of the pump chip 6 itself, the pump light has a large divergence angle. This embodiment solves the problem of large divergence angle by setting the fast-axis shaping prism 32 and the slow-axis shaping prism 33 to shape the pump light into parallel light. Then, it enters the collimated rare-earth-doped amplifying fiber 72 through the wave combiner prism 53 for fiber excitation.

[0051] As an optimized solution for an embodiment of the present invention, please refer to Figure 1 , Figure 2 and Figure 3 The housing 1 has a first mounting area 14 and a second mounting area 15 arranged side by side. The signal transmitting chip 2 is disposed in the first mounting area 14, and the pump chip 6 is disposed in the second mounting area 15. Preferably, the second mounting area 15 has a stepped structure, and the direction from the higher platform to the lower platform of the stepped structure is consistent with the direction of the pump light output of the pump chip 6. A heat insulation strip 16 is provided between the first mounting area 14 and the second mounting area 15. In this embodiment, two mounting areas are designed to allow for the separate placement of the signal transmitting chip 2 and the pump chip 6, respectively. The signal transmitting chip 2, the first collimating lens 31, the first polarization isolator 41, the PBS polarization beam splitter 51, and the filter 52 are mounted on the housing 1 via a TEC9. For example, the hot side of the TEC9 is disposed inside the housing 1, and the above-mentioned components are disposed on the cold side 91 of the TEC9. The housing 1 has a first mounting area 14 and a second mounting area 15, wherein the hot side of the TEC9 is disposed on the first mounting area 14 of the housing 1. The second mounting area 15 can be configured as a stepped structure to serve as a height matching pad for the optical path of the pump chip 6. A heat insulation strip 16 can also be provided between the first mounting area 14 and the second mounting area 15. The heat insulation strip 16 can be configured with a recessed strip opening in the corresponding area inside the housing 1 to reduce heat conduction between the pump chip 6 and the signal emitting chip 2, and to prevent the large amount of heat generated by the pump chip 6 from affecting the light emission performance of the signal emitting chip 2.

[0052] As an optimized solution for an embodiment of the present invention, please refer to Figure 1 , Figure 2 and Figure 3 The optical fiber 71 can be an optical fiber with an APC connector 711.

[0053] As an optimized solution for an embodiment of the present invention, please refer to Figure 1 , Figure 2 and Figure 3The housing 1 has a gold finger connector 11 for circuit connection at one end, and a light output port 12 and a collimating rare-earth-doped amplifying fiber 72 inlet 13 at the other end. The light output port 12 is provided with a light-emitting fiber 71, the collimating rare-earth-doped amplifying fiber 72 inlet 13 is provided with a collimating rare-earth-doped amplifying fiber 72, and a Faraday rotator mirror 8 is fused to the other end of the collimating rare-earth-doped amplifying fiber 72.

[0054] Example 2:

[0055] Please see Figure 1 , Figure 2 and Figure 3 This invention provides a coupling method for the aforementioned fiber laser. It includes the following steps: S1, attaching the signal emitting chip 2 and the pump chip 6 to a predetermined position on the housing 1; S2, coupling the pump optical path of the pump chip 6; S3, then coupling the signal optical path of the signal emitting chip 2; S4, continuing to couple the output optical fiber 71; S5, finally coupling a second collimating lens 34, which collimates the signal light processed by the first optical path assembly and outputs it to the output optical fiber 71.

[0056] As an optimized embodiment of the present invention, step S1 mainly involves patching and wire bonding. The specific coupling is as follows: the signal transmitting chip 2, the first polarization isolator 41, the second polarization isolator 42, the filter 52, the pump chip 6, and the wave combiner prism 53 are mounted on the housing 1 at a preset position. Specifically, the signal transmitting chip 2 is first mounted and fixed in the preset position using the central axis of the optical output port 12 of the housing 1 and the side wall of the housing 1 as positioning references. The first polarization isolator 41 is fixed in the preset position using the light-emitting strip of the signal transmitting chip 2 as a positioning reference. The second polarization isolator 42 is fixed in the preset position using the side wall of the housing as a positioning reference. The pump chip 6 is mounted and fixed in the preset position using the central axis of the collimating rare-earth-doped amplifying fiber 72 inlet 13 of the housing 1 and the side wall of the housing 1 as positioning references. The wave combiner prism 53 is fixed in a preset position using the light-emitting strip of the pump chip 6 and the edge of the pump chip 6 as positioning references. The filter 52 is fixed in a preset position using the wave combiner prism 53 and the side wall of the housing as positioning references. In this coupling step, by first mounting the signal transmitting chip 2 and the pump chip 6 with the housing 1 (the central axis of the optical output port 12, the central axis of the collimating rare-earth-doped amplifying fiber 72 input port 13, and the side wall of the housing 1) as positioning references, and then mounting the first polarization isolator 41 / wave combiner prism 53 with the light-emitting strip of the corresponding signal transmitting chip 2 / pump chip 6 as positioning references, the optical path offset and loss caused by mounting deviation can be minimized, thereby improving the coupling efficiency of the optical path.

[0057] As an optimized embodiment of the present invention, the coupling method of step S2 is as follows: S20, connect the tail end of the collimating rare-earth-doped amplifying fiber 72 to the optical power meter via fusion splicing; S21, power on the pump chip 6; S22, move the position of the collimating rare-earth-doped amplifying fiber 72 relative to the collimating rare-earth-doped amplifying fiber 72 inlet 13 of the housing 1; S23, observe the reading of the optical power meter until the position that maximizes the optical power meter reading is found, record it, and fix the collimating rare-earth-doped amplifying fiber 72 at the corresponding position on the housing 1; S24, adjust the fast axis shaping edge... S22: Mirror 32 is placed in a preset initial position. The pump chip 6 is powered on. The fast-axis shaping prism 32 is moved, and the reading of the optical power meter is observed until the maximum reading of the optical power meter is found. The reading is recorded, and the fast-axis shaping prism 32 is fixed at the corresponding position on the housing 1. S25: The slow-axis shaping prism 33 is placed in a preset initial position. The pump chip 6 is powered on. The slow-axis shaping prism 33 is moved, and the reading of the optical power meter is observed until the maximum reading of the optical power meter is found. The reading is recorded, and the slow-axis shaping prism 33 is fixed at the corresponding position on the housing 1. Specifically, in steps S20-S23, since the wave combiner prism 53 will cause a certain offset to the pump optical path, by first attaching the wave combiner prism 53 and then coupling the collimating rare-earth-doped amplifying fiber 72, the collimating rare-earth-doped amplifying fiber 72 can be coupled more accurately, and at the same time, the optimal coupling efficiency can be achieved. Using collimated rare-earth-doped amplifying fiber 72 to directly receive the divergent light emitted by pump chip 6 for coupling, the optimal coupling point can be found more accurately and quickly (since the amount of divergent light that can be received is small, if it is slightly misaligned, the light will not be received, so if the light can be received and the point with the maximum optical power is found, the coupling can be completed quickly and a high coupling accuracy can be guaranteed).

[0058] As an optimized embodiment of the present invention, the coupling method of step S3 is as follows: S30, the first collimating lens 31 and the PBS polarization beam splitter 51 are placed in a first preset initial position with the light-emitting strip of the signal transmitting chip 2 as the positioning reference; S31, the signal transmitting chip 2 is powered on, and the optical power reading of the collimated rare-earth-doped amplifying fiber 72 at the tail end is observed; S32, the position of the first collimating lens 31 is moved to find the position of the first collimating lens 31 when the PBS polarization beam splitter 51 is placed in the first preset initial position, and the position of the first collimating lens 31 and the first maximum value of the optical power meter are recorded at this time; S33, the position of the PBS polarization beam splitter 51 is moved according to a certain motion logic, and then the position of the first collimating lens 31 is readjusted until the reading of the optical power meter reaches a new second maximum value under the current position of the first collimating lens 31, and the position of the first collimating lens 31 and the optical power are recorded at this time. S34. Compare the first maximum value and the second maximum value to determine the subsequent movement direction of the PBS polarization beam splitter 51; S35. After the PBS polarization beam splitter 51 moves, repeat the adjustment of the first collimating lens 31 to obtain the maximum power value; S36. Repeat the above operation until the optimal matching position of the first collimating lens 31 and the PBS polarization beam splitter 51 that maximizes the power value is found, and record the position of the first collimating lens 31 and the position of the PBS polarization beam splitter 51 respectively; S37. Then keep the position of the first collimating lens 31 and the position of the PBS polarization beam splitter 51 unchanged; with the axis extending in the direction of the signal light output by the signal transmitting chip 2 as the rotation center axis, make the PBS polarization beam splitter 51 rotate around the rotation center axis to fine adjust the angle of the PBS polarization beam splitter 51 until the reading of the optical power meter reaches the maximum value and then stop. Specifically, in steps S30-S32, the first collimating lens 31 and the PBS polarizing beam splitter 51 are placed at a first preset initial position using the light-emitting strip of the signal transmitting chip 2 as a positioning reference. This facilitates reducing coupling difficulty and improving coupling speed. In step S34, the subsequent movement direction of the PBS polarizing beam splitter 51 is determined by the ratio between the first maximum value and the second maximum value. If the second maximum value is greater than the first maximum value, the PBS polarizing beam splitter 51 continues to move a certain position in the same direction; otherwise, it moves in the opposite direction.In step S37, the extended axis can specifically be an axis extending in the direction of light passing through the center of the 45° inclined plane of the beam splitter 511, thereby changing the angle of the PBS polarizing beam splitter mirror 51 and finding the optical power meter reading to reach its maximum value. By finely adjusting the angle of the PBS polarizing beam splitter mirror 51, we can correct the optical path for slight deviations caused by material tolerances or mounting tolerances, thereby improving coupling efficiency.

[0059] As an optimized embodiment of the present invention, the coupling method in step S4 is as follows: Disconnect the tail end of the collimating rare-earth-doped amplifying fiber 72 from the fusion-connected optical power meter and connect it to the Faraday rotator mirror 8. Connect the output fiber 71 to the optical power meter. Power on the signal transmitting chip 2 and the pump chip 6. Adjust the position of the output fiber 71 until the reading of the optical power meter reaches its maximum value. Since the optical path of the output fiber 71 is relatively long, this scheme, by powering on the signal transmitting chip 2 and the pump chip 6, puts the fiber laser system into operation. Using the signal light received by the output fiber 71 and amplified by the collimating rare-earth-doped amplifying fiber 72 as the coupling index, it is easier to observe parameter changes, easier to couple, and the coupling accuracy is also high.

[0060] As an optimized solution of this invention, the coupling method of step S4 is as follows: in the same way as step 71 of coupling out optical fiber, power on signal transmitting chip 2 and pump chip 6, and adjust the position of second collimating lens 34 until the optical power meter reading reaches the maximum value.

[0061] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A fiber laser, characterized in that: The device includes a housing, a signal transmitting chip, and a pump chip. Both the signal transmitting chip and the pump chip are coupled and encapsulated within the housing. The housing is connected to an output optical fiber and a collimating rare-earth-doped amplifying optical fiber. The collimating rare-earth-doped amplifying optical fiber is connected to a Faraday rotator. The signal light output from the signal transmitting chip is processed by a first optical path component, first input to the Faraday rotator via the collimating rare-earth-doped amplifying optical fiber, then returns to the housing and is output from the output optical fiber. The pump light signal output from the pump chip is processed by a second optical path component and then input to the collimating rare-earth-doped amplifying optical fiber. The housing has a first mounting area and a second mounting area arranged side-by-side. The signal transmitting chip is located in the first mounting area, and the pump chip is located in the second mounting area. A heat insulation strip is provided between the first and second mounting areas to reduce heat conduction between the pump chip and the signal transmitting chip. The first optical path component includes a first collimating lens, a first polarization isolator, a PBS polarization beam splitter, a filter, and a beam combiner prism. The second optical path component includes a fast-axis shaping prism and a slow-axis shaping prism.

2. The fiber laser as described in claim 1, characterized in that: The signal light output by the signal transmitting chip passes sequentially through the first collimating lens, the first polarization isolator, the PBS polarization beam splitter, the filter, and the beam combiner prism before entering the collimated rare-earth-doped amplifying fiber.

3. The fiber laser as described in claim 1, characterized in that: The pump light emitted by the pump chip passes sequentially through the fast-axis shaping prism and the slow-axis shaping prism, and then enters the collimated rare-earth-doped amplifying fiber through the wave combiner prism.

4. The fiber laser as described in claim 1, characterized in that: The second installation area has a stepped structure, and the direction from the higher platform to the lower platform of the stepped structure is consistent with the direction of the pump light output of the pump chip.

5. A coupling method for a fiber laser according to any one of claims 1-4, characterized in that, Includes the following steps: S1, the signal transmitting chip and the pump chip are mounted on the housing at a preset position; S2, the pump optical path of the pump chip is coupled; S3, then the signal optical path of the signal transmitting chip is coupled; S4, continue coupling the output optical fiber; S5, finally, the second collimating lens is coupled. The second collimating lens is used to collimate the signal light processed by the first optical path component and output it to the light-emitting optical fiber.

6. The coupling method as described in claim 5, characterized in that, In step S1, the first polarization isolator, the second polarization isolator, the filter, and the wave combiner prism are also attached to the preset positions of the housing, specifically: The signal transmitting chip is first fixed in a preset position using the central axis of the optical output port of the housing and the side wall of the housing as positioning references; The first polarization isolator is fixed in a preset position with the light-emitting strip of the signal transmitting chip as the positioning reference; The second polarization isolator is fixed in a preset position with the side wall of the housing as the positioning reference; The pump chip is fixed in a preset position with the rare earth-doped optical fiber inlet center axis of the housing and the side wall of the housing as positioning references. The wave-combining prism is fixed in a preset position using the light-emitting strip of the pump chip and the edge of the pump chip as positioning references. The filter is fixed in a preset position using the wave-combining prism and the side wall of the housing as positioning references.

7. The coupling method as described in claim 5, characterized in that, The coupling method in step S2 is as follows: S20, the tail end of the collimated rare-earth-doped amplifying fiber is connected to the optical power meter via fusion splicing. S21, Power on the pump chip. S22, Move the position of the collimated rare-earth-doped amplifying fiber relative to the collimated rare-earth-doped amplifying fiber inlet of the housing. S23, observe the reading of the optical power meter until the position that maximizes the optical power meter reading is found, record the value, and fix the collimating rare-earth-doped amplifying fiber at the corresponding position on the housing. S24, place the fast-axis shaping prism in a preset initial position, power on the pump chip, move the fast-axis shaping prism, observe the reading of the optical power meter until the maximum reading of the optical power meter is found, record the reading, and fix the fast-axis shaping prism in the corresponding position on the housing. S25, place the slow-axis shaping prism in a preset initial position, power on the pump chip, move the slow-axis shaping prism, observe the reading of the optical power meter until the maximum reading of the optical power meter is found, record it, and fix the slow-axis shaping prism in the corresponding position of the housing.

8. The coupling method as described in claim 5, characterized in that, The coupling method in step S3 is as follows: S30, using a first collimating lens and a PBS polarizing beam splitter, with the light-emitting strip of the signal transmitting chip as the positioning reference, is placed in a first preset initial position; S31, Power on the signal transmitting chip and observe the optical power reading of the collimated rare-earth-doped amplifying fiber tail splice. S32, Move the position of the first collimating lens to find the position of the first collimating lens when the PBS polarizing beam splitter is placed in the first preset initial position, and record the position of the first collimating lens and the first maximum value of the optical power meter at this time; S33, move the position of the PBS polarizing beam splitter, and then readjust the position of the first collimating lens until the reading of the optical power meter reaches the new second maximum value at the current position of the first collimating lens. Record the current position of the first collimating lens and the second maximum value of the optical power meter. S34, compare the first maximum value and the second maximum value to determine the subsequent motion direction of the PBS polarizing beam-splitting mirror; S35, after the PBS polarizing beam-splitting mirror is moved, the first collimating lens is adjusted again to obtain the maximum power value; S36, Repeat the above operation until the optimal matching position of the first collimating lens and the PBS polarizing beam splitter is found that maximizes the power value, and record the position of the first collimating lens and the position of the PBS polarizing beam splitter respectively. S37, then keep the position of the first collimating lens and the position of the PBS polarizing beam-splitting mirror unchanged; Using the axis extending in the direction of the signal light output from the signal transmitting chip as the rotation center axis, the PBS polarizing beam splitter mirror rotates around the rotation center axis to finely adjust the angle of the PBS polarizing beam splitter mirror until the reading of the optical power meter reaches its maximum value and then stops.

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