Anti-backlighting module and fiber laser

Abstract

The application discloses a kind of anti-return light module and fiber laser, the anti-return light module includes shell, focusing lens structure and pump source structure, the shell is formed with output port, the output port is used to set gain optical fiber, the focusing lens structure is along first direction relative to the output port in the shell, the focusing lens structure has the avoidance in middle, and focusing portion is at the avoidance peripheral side, the pump source structure is along first direction relative to the focusing lens structure in the shell, the pump source structure is used to emit pump light towards the focusing portion along first direction, pump light from the focusing portion can be focused and coupled into gain optical fiber, laser emitted from gain optical fiber in reverse can pass through the avoidance, and will not return to the pump source structure, so as to avoid the damage of semiconductor chip therein, improve the light-emitting stability of the anti-return light module.

Description

Technical Field

[0001] This invention relates to the field of fiber laser technology, and particularly to anti-return optical modules and fiber lasers. Background Technology

[0002] In the gain structure of fiber lasers, there are usually two pump light injection methods: forward pumping and reverse pumping. However, in existing fiber lasers, regardless of the pumping method, multiple pump sources need to be combined into a high-power beam using a beam combiner. However, the beam combiner itself has problems with beam combining loss and heat generation. At the same time, when using high-power pump sources, there is also the problem of back laser. Back laser will propagate in the opposite direction along the pump optical path into the semiconductor chip of the pump source, which can easily lead to semiconductor chip failure. Summary of the Invention

[0003] The main objective of this invention is to propose an anti-return laser module and a fiber laser, aiming to solve the problem that the return laser in existing fiber lasers can easily cause semiconductor chip failure when the high-power pump source is working.

[0004] To achieve the above objectives, the anti-return optical module proposed in this invention includes:

[0005] The housing has an output port for housing a gain fiber.

[0006] A focusing lens structure is disposed on the housing relative to the output port along a first direction. The focusing lens structure has a clearance portion in the middle and a focusing portion located around the clearance portion; and...

[0007] A pump source structure is disposed on the housing relative to the focusing lens structure along a first direction, and the pump source structure is used to emit pump light toward the focusing part along the first direction;

[0008] Pump light passing through the focusing section is focused and coupled into the gain fiber.

[0009] Laser light emitted in the reverse direction from the self-gain fiber can pass through the clearance section.

[0010] Optionally, the anti-return optical module further includes a photodetector, which is disposed on the housing opposite to the avoidance part and on the same side of the pump source structure, for receiving laser light that returns through the avoidance part via the gain fiber.

[0011] Optionally, the pump source structure includes multiple sets of pump light emitting units, which are arranged around the periphery of the avoidance portion.

[0012] Optionally, each of the pump light emitting units includes multiple pump light emitting elements, which are arranged in a staggered manner in a first direction and are all used to emit pump light toward the focusing portion.

[0013] Optionally, each of the pump light emitting units further includes a plurality of reflectors, each of the reflectors being disposed corresponding to a plurality of the pump light emitting elements, for reflecting the pump light emitted from the pump light emitting elements along a first direction to the focusing portion.

[0014] Optionally, the anti-return optical module further includes a heat sink structure, which is arranged in a stepped manner on the housing to form multiple stepped surfaces. In a first direction, the multiple stepped surfaces decrease in sequence, and the multiple pump light emitting elements are respectively disposed on the multiple stepped surfaces.

[0015] Optionally, a clearance hole is formed in the middle of the heat sink structure, which extends along a first direction, and the clearance hole is disposed corresponding to the clearance portion. In the first direction, a plurality of pump light emitting elements are disposed around the clearance hole.

[0016] Optionally, the pump light emitting element includes a semiconductor chip, a fast-axis collimating lens, and a slow-axis collimating lens arranged in sequence. The pump light emitted from the semiconductor chip passes through the fast-axis collimating lens and the slow-axis collimating lens in sequence to collimate the fast-axis and slow-axis directions.

[0017] To achieve the above objectives, the fiber laser proposed in this invention includes the aforementioned anti-return light module.

[0018] Optionally, the fiber laser further includes a gain fiber having a coupling end located at the output port.

[0019] In the technical solution provided by this invention, spatial beam combining is used instead of the traditional beam combiner method. The focusing lens structure focuses the pump light emitted from the pump source structure onto the gain fiber in the output port, thereby achieving high-power pump light output while reducing beam combining loss and heat generation. Moreover, since the focusing lens structure is divided into a central clearance section and a focusing section around the clearance section, and the pump source structure only emits pump light toward the focusing section, and since the divergence angle of the gain fiber is limited, by reasonably controlling the distance between the gain fiber and the focusing lens structure, the laser light emitted from the gain fiber toward the focusing lens structure will only illuminate the area of ​​the clearance section. Therefore, the laser light that passes back through the clearance section will not return to the pump source structure, that is, it will not damage the semiconductor chip in the pump source structure, thus improving the light emission stability of the anti-return optical module. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the optical path of an embodiment of the anti-return optical module provided by the present invention;

[0022] Figure 2 for Figure 1 A planar schematic diagram of the focusing lens structure in the image;

[0023] Figure 3 for Figure 1 A schematic diagram of the assembly of the return optical module and the heat sink structure in the China Defense system;

[0024] Figure 4 for Figure 3 The diagram shows the structure of the pump light emitting element and the heat sink combination.

[0025] Explanation of icon numbers:

[0026] 100 Anti-return optical module 2112 Fast axis collimating lens 1 Focusing lens structure 2113 Slow-axis collimating lens 11 Avoidance section 3 reflector 12 Focus Department 4 heat sink structure 2 Pump source structure 41 Step surface 21 Pump light emitting unit 42 clearance hole 211 Pump light emitting element 200 Gain fiber 2111 semiconductor chips

[0027] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] It should be noted that if the embodiments of the present invention involve directional indication, the directional indication is only used to explain the relative positional relationship and movement of the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0030] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0031] In view of this, the present invention proposes an anti-return optical module and a fiber laser, aiming to solve the problem that returned laser light during the operation of high-power pump sources in existing fiber lasers can easily cause semiconductor chip failure. Figures 1 to 4 This is a schematic diagram of the optical path and structure of an embodiment of the anti-return optical module provided by the present invention.

[0032] Please see Figures 1 to 2 The anti-return optical module 100 includes a housing, a focusing lens structure 1, and a pump source structure 2. The housing has an output port for mounting a gain fiber 200. The focusing lens structure 1 is disposed in the housing relative to the output port along a first direction. The focusing lens structure 1 has a central clearance portion 11 and a focusing portion 12 located around the clearance portion 11. The pump source structure 2 is disposed in the housing relative to the focusing lens structure 1 along the first direction. The pump source structure 2 is used to emit pump light towards the focusing portion 12 along the first direction. The pump light passing through the focusing portion 12 can be focused and coupled into the gain fiber 200. The laser light emitted in the opposite direction from the gain fiber 200 can pass through the clearance portion 11.

[0033] In the technical solution provided by this invention, spatial beam combining is used instead of the traditional beam combiner method. The focusing lens structure 1 focuses the pump light emitted from the pump source structure 2 onto the gain fiber 200 in the output port, thereby achieving high-power pump light output while reducing beam combining loss and heat generation. Moreover, since the focusing lens structure 1 is divided into the avoidance part 11 in the middle and the focusing part 12 around the avoidance part 11, and the pump source structure 2 only emits pump light toward the focusing part 12, and according to the divergence angle of the gain fiber 200, under the reasonable control of the distance between the gain fiber 200 and the focusing lens structure 1, the laser emitted from the gain fiber 200 toward the focusing lens structure 1 will only illuminate the range of the avoidance part 11. Therefore, the laser light that passes back through the avoidance part 11 will not return to the pump source structure 2, that is, it will not damage the semiconductor chip 2111 in the pump source structure 2, thus improving the light emission stability of the anti-return light module 100.

[0034] Since pump light injection in a gain structure typically involves both forward pumping and reverse pumping, the anti-return optical module 100 in this embodiment can also be used for at least forward pumping and reverse pumping. When the anti-return optical module 100 is used for reverse pumping, the laser can be output through a region with higher peak power, which is the region corresponding to the avoidance part 11. When the anti-return optical module 100 is used for forward pumping, in this embodiment, the anti-return optical module 100 further includes a photodetector. The photodetector is disposed on the housing opposite to the avoidance part 11 and on the same side of the pump source structure 2 to receive the laser light that returns through the avoidance part 11 via the gain fiber 200. By setting the photodetector corresponding to the avoidance part 11, the laser power returning through the avoidance part 11 can be detected, and the output power of the fiber laser can be derived from this.

[0035] To improve the output power of the anti-return optical module 100, in this embodiment, the pump source structure 2 includes multiple sets of pump light emitting units 21, which are arranged around the periphery of the avoidance portion 11. It is understood that the entire area of ​​the focusing portion 12 can be used as an incident point. Therefore, to fully utilize the focusing effect of the focusing portion 12, multiple sets of pump light emitting units 21 are arranged around the periphery of the avoidance portion 11, ensuring that the pump light emitted by each set of pump light emitting units 21 enters the focusing portion 12 along a first direction.

[0036] Furthermore, each of the pump light emitting units 21 includes a plurality of pump light emitting elements 211, which are arranged in a staggered manner in a first direction and are all used to emit pump light toward the focusing section 12. By staggering the arrangement of the plurality of pump light emitting elements 211 in the first direction, it can be ensured that the pump light emitted by each pump light emitting element 211 can illuminate the focusing section 12, thereby maximizing the focusing effect of the focusing section 12.

[0037] Because the pump light emitting elements 211 are structurally complex, they inevitably require considerable installation space. Installing the pump light emitting elements 211 along the first direction and directly emitting light towards the focusing unit 12 would undoubtedly result in an excessively large anti-return light module 100. Therefore, each pump light emitting unit 21 also includes multiple reflectors 3, each corresponding to one of the multiple pump light emitting elements 211, to reflect the pump light emitted from the pump light emitting elements 211 along the first direction to the focusing unit 12. By changing the optical path direction of the multiple pump light emitting units 21 through the multiple reflectors 3, the pump light generating units have more arrangement possibilities, thereby making fuller use of the installation space and achieving a better balance between the installation volume of the anti-return light module 100 and the pump light emission power, maximizing output efficiency.

[0038] The staggered arrangement of the multiple pump light emitting elements 211 can take many forms, but for ease of installation, please refer to [the relevant documentation]. Figure 3 and Figure 4 In this embodiment, the anti-return optical module 100 further includes a heat sink structure 4, which is steppedly disposed on the housing to form multiple stepped surfaces 41. In a first direction, the multiple stepped surfaces 41 decrease in height sequentially, and the multiple pump light emitting elements 211 are respectively disposed on the multiple stepped surfaces 41. The heat sink structure 4 provides a basis for the staggered installation of the pump light emitting units 21 and also plays an effective role in heat conduction, ensuring the stability of the pump light emitting elements 211.

[0039] Furthermore, a clearance hole 42 is formed in the middle of the heat sink structure 4, extending along a first direction. The clearance hole 42 is disposed corresponding to the clearance part 11. In the first direction, a plurality of pump light emitting elements 211 are disposed around the clearance hole 42. The clearance hole 42 allows laser light returning through the clearance part 11 to pass through, thus not affecting the output of the anti-return light module 100. At the same time, since a plurality of pump light emitting elements 211 are disposed around the clearance hole 42 in the first direction, it is possible to install multiple pump light emitting elements 211 in multiple pump light generating units using one heat sink structure 4 even with staggered arrangement. This arrangement around the clearance hole 42 can maximize the utilization of each step of the heat sink structure 4, that is, maximize the focusing area of ​​the focusing part 12, thereby maximizing the power of the output pump light.

[0040] Specifically, the pump light emitting element 211 includes a semiconductor chip 2111, a fast-axis collimating lens 2112, and a slow-axis collimating lens 2113 arranged in sequence. The pump light emitted from the semiconductor chip 2111 passes through the fast-axis collimating lens 2112 and the slow-axis collimating lens 2113 in sequence to collimate in the fast and slow axis directions. The fast-axis collimating lens 2112 and the slow-axis collimating lens 2113 can form a collimation module, which can simultaneously reduce the divergence of the pump light emitted by the semiconductor chip 2111 in the fast and slow axes, ensuring that the pump light is compressed and collimated, that is, ensuring that the pump light emitted by the pump light emitting element 211 has good beam quality.

[0041] In other embodiments, the pump light emitting element 211 may be configured in other ways. For example, a single diode laser tube may be used alone in conjunction with other types of collimation modules to output high-quality pump light. This embodiment of the present invention will not elaborate on this.

[0042] Furthermore, to achieve the above objectives, the present invention also provides a fiber laser, which includes the anti-return optical module 100 described in the above technical solution. It should be noted that the detailed structure of the anti-return optical module 100 of the fiber laser can be referred to the embodiments of the anti-return optical module 100 described above, and will not be repeated here. Since the anti-return optical module 100 is used in the fiber laser of the present invention, the embodiments of the fiber laser of the present invention include all the technical solutions of all the embodiments of the anti-return optical module 100, and the achieved technical effects are also completely the same, and will not be repeated here.

[0043] Furthermore, the fiber laser also includes a gain fiber 200, which has a coupling end located at the output port.

[0044] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made under the concept of the present invention using the description and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A backlash prevention optical module, characterized in that, include: The housing has an output port for housing a gain fiber. A focusing lens structure is disposed on the housing relative to the output port along a first direction. The focusing lens structure has a clearance portion in the middle and a focusing portion on the periphery of the clearance portion. as well as, A pump source structure is disposed on the housing relative to the focusing lens structure along a first direction, and the pump source structure is used to emit pump light toward the focusing portion along the first direction; Pump light passing through the focusing section is focused and coupled into the gain fiber. Laser light emitted in the reverse direction from the self-gain fiber can pass through the clearance section; The anti-return optical module also includes a photodetector, which is disposed on the housing opposite to the avoidance part and on the same side of the pump source structure, for receiving laser light that returns through the avoidance part via the gain fiber; The pump source structure includes multiple sets of pump light emitting units, and the multiple sets of pump light emitting units are arranged around the periphery of the avoidance part; Each of the pump light emitting units includes multiple pump light emitting elements, which are arranged in a staggered manner in a first direction and are all used to emit pump light toward the focusing part; The anti-return optical module also includes a heat sink structure, which is arranged in a stepped manner on the housing to form multiple stepped surfaces. In a first direction, the multiple stepped surfaces decrease in sequence, and the multiple pump light emitting elements are respectively arranged on the multiple stepped surfaces.

2. The anti-return optical module as described in claim 1, characterized in that, Each of the pump light emitting units further includes a plurality of reflectors, each of the reflectors being disposed corresponding to a plurality of the pump light emitting elements, for reflecting the pump light emitted from the pump light emitting elements along a first direction to the focusing portion.

3. The anti-return optical module as described in claim 1, characterized in that, The heat sink structure has a through hole in the middle that runs along a first direction, and the through hole is provided corresponding to the clearance part. In the first direction, a plurality of pump light emitting elements are provided around the through hole.

4. The anti-return optical module as described in claim 1, characterized in that, The pump light emitting element includes a semiconductor chip, a fast-axis collimating lens, and a slow-axis collimating lens arranged in sequence. The pump light emitted from the semiconductor chip passes through the fast-axis collimating lens and the slow-axis collimating lens in sequence to be collimated in the fast-axis and slow-axis directions.

5. A fiber laser, characterized in that, Includes the anti-return optical module as described in any one of claims 1 to 4.

6. The fiber laser as described in claim 5, characterized in that, The fiber laser also includes a gain fiber, which has a coupling end located at the output port.

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