Method for quickly replacing output tail fiber of low-power laser and laser thereof

Abstract

The invention discloses a low-power laser output tail fiber rapid replacement method and a laser thereof, and the method comprises the following steps: S1, installing a new output tail fiber, and transmitting a light beam to the new output tail fiber; s2, collecting a focus spot image of the light beam; s3, according to the light spot image information, judging whether the focusing of the light beam and a new output tail fiber is completed; and S4, adjusting the focus of the light beam according to a judgment result, so that coupling and focusing of the output tail fiber and the light beam are completed. When the output tail fiber of the laser is damaged, the rapid replacement of the output tail fiber and the coupling of the output tail fiber and the light beam are realized through the steps, and part of optical devices in the pumping source of the laser do not need to be replaced. Compared with a method in the prior art that once the output tail fiber is damaged, part of normal devices in the pumping source and the damaged output tail fiber need to be directly replaced, the method provided by the invention ensures enough light beam coupling efficiency on the premise of saving cost.

Description

Technical Field

[0001] The present application belongs to the field of optical fiber laser technology, and specifically relates to a method for quickly replacing a low-power laser output pigtail and a laser thereof. Background Art

[0002] Laser technology is one of the most important technologies in the field of optics. As a representative of the third generation of laser technology, it has advantages such as compact structure, good beam quality, high stability, and high cost-effectiveness. This makes it important for applications in fiber optic sensing, fiber optic communications, and industrial processing.

[0003] Existing lasers typically include a pump source with a basic optical path (i.e., a light output unit) and a power transmission unit for transmitting signal and pump light. Due to assembly errors when the output fiber is installed on the pump source housing, the new output fiber does not align with the old basic optical path. Therefore, when the output fiber of an existing laser is damaged, replacing the output fiber requires realigning the light output unit inside the pump source housing to align the focus of the converging light beam emitted by the light output unit with the new output fiber. This operation involves the removal and replacement of the light output unit or some of its components within the pump source. Some components of the light output unit may be damaged during disassembly and cannot be reused, significantly increasing the cost of laser repair.

[0004] Therefore, it is necessary to design a method for quickly replacing the output fiber of a low-power laser and a laser with low rework cost. Summary of the Invention

[0005] The purpose of this application is to address the shortcomings of the existing technology and provide a method for quickly replacing a low-power laser output pigtail and a laser thereof, aiming to solve the problem of high fiber replacement cost in the existing technology.

[0006] To achieve the above objectives, the technical solution adopted in this application is: A method for quickly replacing a low-power laser output pigtail is used to repair a low-power laser with a damaged output pigtail, and is characterized by comprising the following steps: S1. Install a new output fiber pigtail and emit a light beam to the new output fiber pigtail; S2, collecting the focal spot image of the light beam; S3, judging whether the light beam is focused on the new output fiber according to the light spot image information; S4. Adjust the focus of the light beam according to the judgment result so that the output fiber pigtail is in focus with the light beam.

[0007] As a preferred solution, the light spot image information includes the measured diameter of the light spot and the measured center point position information of the light spot.

[0008] As a preferred solution, when the measured diameter of the light spot is equal to the preset diameter, and the measured center point position of the light spot is consistent with the preset center point position, it is determined that the focusing is completed.

[0009] As a preferred solution, when the measured diameter of the light spot is not equal to the preset diameter, and / or the measured center point position of the light spot is inconsistent with the preset center point position, it is determined that the focus is not completed, and the focus of the light beam is adjusted until the focus is completed.

[0010] According to another aspect of the present application, a laser is further provided, wherein a pump source of the laser is connected to a laser output head via an output pigtail, and the output pigtail is replaced using any of the above-mentioned methods for quickly replacing a low-power laser output pigtail, characterized in that the laser comprises: A light emitting unit is provided inside the pump source for emitting a light beam; A focusing unit is provided along the light-emitting direction of the light beam and is also provided inside the pump source to adjust the focal position of the light beam; An image acquisition unit, the image acquisition unit is used to acquire a spot image of the focused light beam; A signal processing unit, the signal processing unit is electrically connected to the image acquisition unit and is used to determine whether the output pigtail focusing is completed according to the light spot image information; The main control board is electrically connected to the signal processing unit. The signal processing unit is also used to send the judgment result to the main control board. The main control board controls whether the focusing unit focuses or not according to the judgment result.

[0011] As a preferred solution, it is characterized in that the focusing unit includes: First wedge mirror; A second wedge-shaped mirror, wherein the first wedge-shaped mirror and the second wedge-shaped mirror are sequentially arranged along the optical axis of the light beam and are centrally symmetrically arranged, and the exit surface of the first wedge-shaped mirror corresponds to the incident surface of the second wedge-shaped mirror; an adjusting member connected to the first wedge-shaped mirror and the second wedge-shaped mirror, and configured to adjust a distance between the first wedge-shaped mirror and the second wedge-shaped mirror along the optical axis, and / or move at least one of the first wedge-shaped mirror and the second wedge-shaped mirror along an extending direction of an incident surface of the first wedge-shaped mirror, and / or rotate at least one of the first wedge-shaped mirror and the second wedge-shaped mirror at a predetermined angle along the optical axis; and a driving mechanism, which is connected to the adjusting member and electrically connected to the main control board, and is used to control the adjusting member to drive the first wedge-shaped mirror and / or the second wedge-shaped mirror to move according to a control signal sent by the main control board.

[0012] As a preferred solution, it is characterized in that an output fiber pigtail coupling port is provided on the pump source, and the output fiber pigtail coupling port is provided on the light output side of the focusing unit for assembling the output fiber pigtail.

[0013] As a preferred solution, it is characterized in that the focusing unit further includes a cylindrical lens group, which is arranged in front of the incident surface of the first wedge-shaped mirror to converge the incident light beam.

[0014] As a preferred solution, it is characterized in that the output fiber pigtail is installed in the armored cable, and the light beam output from the pump source is gain-amplified after passing through the armored cable to form a laser.

[0015] As a preferred solution, it is characterized in that a first grating group and a second grating group are sequentially engraved on the output fiber pigtail, the first grating group includes a first cladding grating and a first core grating, and the second grating group includes a second core grating and a second cladding grating; the reflectivity of the first cladding grating, the first core grating and the second cladding grating for laser light in a predetermined wavelength band is higher than the reflectivity of the second core grating for laser light in a predetermined wavelength band.

[0016] Compared with the prior art, the present invention has the following advantages: Regarding the first aspect proposed in the present application, i.e., a method for quickly replacing a low-power laser output pigtail, when the laser output pigtail is damaged, the quick replacement method proposed in the present application can directly achieve quick replacement of the output pigtail and coupling with the light beam, while ensuring a high light beam coupling efficiency without having to replace some optical components inside the laser pump source, thereby greatly reducing maintenance costs; Regarding the second aspect of this application, namely, a laser using the aforementioned method for replacing an output fiber pigtail, the laser of this application adds a focusing unit comprising a first wedge-shaped mirror and a second wedge-shaped mirror to the pump source. When the optical fiber armor cable is damaged, the relative position of the two wedge-shaped mirrors can be directly changed via an adjustment member connected to the drive mechanism, thereby changing the optical path to achieve focus adjustment and thereby ensuring beam coupling efficiency. Compared to the prior art method, which requires directly replacing some healthy components in the pump source and the damaged optical fiber once the optical fiber is damaged, this application eliminates the need to replace internal optical components in the event of optical fiber damage, significantly reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 This is a flow chart of the method for quickly replacing the output fiber pigtail of a low-power laser in this application; Figure 2 This is a schematic diagram of the optical path of a laser in one embodiment of the present application; Figure 3 This is a schematic diagram of the optical path of a laser in another embodiment of the present application; Figure 4 is a schematic cross-sectional view of the first core grating and the second core grating; Figure 5 is a schematic cross-sectional view of the first cladding grating and the second cladding grating; Figure 6 for Figure 1 A schematic cross-sectional view of an output pigtail in the embodiment; Figure 7 for Figure 2 A schematic cross-sectional view of an output pigtail in the embodiment; Figure 8 is a schematic diagram of a first preset position of the light beam; Figure 9 is a schematic diagram of a second preset position of the light beam; Figure 10 Schematic diagram of the third preset position of the light beam.

[0019] Among them, the reference numerals in the figures are: 1. Pump source; 11. Light output unit; 12. Focusing unit; 13. Adjustment member; 14. Cylindrical lens group; 2. Armored cable; 20. Output pigtail coupling port; 21. Fiber core; 22. Cladding; 23. First preset position; 24. Second preset position; 25. Third preset position; 3. First grating group; 31. First cladding grating; 32. First core grating; 4. Second grating group; 41. Second cladding grating; 42. Second core grating; 5. Laser output head. DETAILED DESCRIPTION

[0020] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0021] In the description of this application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a predetermined orientation, be constructed and operated in a predetermined orientation, and therefore cannot be understood as a limitation on this application.

[0022] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified with "first," "second," etc., may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0023] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0024] This application first proposes a method for quickly replacing low-power laser output pigtails. Please refer to Figure 1 , which includes the following steps: S1. Install a new output pigtail and emit a light beam to the new output pigtail; S2, collecting a focal spot image of the light beam; S3, judging whether the light beam is focused on the new output fiber according to the light spot image information; S4. Adjust the focus of the light beam according to the judgment result, so that the output fiber pigtail is coupled with the light beam and the focus is completed.

[0025] It is understood that the spot image information includes the measured diameter of the spot and the measured center point position information of the spot. When the measured diameter of the spot is equal to the preset diameter, and the measured center point position of the spot is consistent with the preset center point position, focus is determined to be complete. When the measured diameter of the spot is not equal to the preset diameter, and / or the measured center point position of the spot is inconsistent with the preset center point position, focus is determined to be incomplete, and the focus of the light beam is adjusted until focus is complete.

[0026] It can be understood that the above-mentioned method for rapid replacement of output fiber pigtails is mainly used for the repair work of low-power lasers with damaged output fiber pigtails. When the output fiber pigtail of the laser is damaged, the rapid replacement method proposed in this application can directly realize the rapid replacement of the output fiber pigtail and its coupling with the light beam, and ensure a high light beam coupling efficiency without the need to replace some optical devices inside the laser pump source, thereby greatly reducing maintenance costs.

[0027] In one embodiment, the execution subject of the above steps may be a laser electrically connected to an electronic device having image acquisition and information processing functions, as proposed in another aspect of the present application.

[0028] Please refer to Figure 2 The laser's pump source 1 is connected to the laser output head 5 via an output fiber pigtail, which is replaced using the aforementioned quick-change method. The pump source 1 has a basic optical path, namely a light output unit 11. This unit typically includes a light output chip, a collimator, and a reflector for emitting a light beam. A focusing unit 12 is located along the light output direction and is also located within the pump source. This unit is used to adjust the focus position of the light beam, thereby aligning the optical axis of the light beam with the core of the output fiber pigtail.

[0029] It is understood that the laser also includes an image acquisition unit (not shown in the figure), a signal processing unit (not shown in the figure), and a main control board (not shown in the figure). The image acquisition unit is used to capture the spot image of the focused light beam; the signal processing unit is electrically connected to the image acquisition unit and is used to determine whether the output fiber pigtail is focused based on the spot image information; the main control board is electrically connected to the signal processing unit, and the signal processing unit is also used to send the judgment result to the main control board, which controls the focusing unit to focus based on the judgment result.

[0030] Optionally, the image acquisition unit may adopt existing devices such as CCD.

[0031] In one embodiment, the spot image information includes the measured diameter of the spot and the measured center position of the spot. When the measured diameter of the spot is equal to the preset diameter, and the measured center position of the spot is consistent with the preset center position, it is determined that the output fiber pigtail and the light beam are in focus. When the measured diameter of the spot is not equal to the preset diameter, and / or the measured center position of the spot is inconsistent with the preset center position, it is determined that the output fiber pigtail and the light beam are not in focus. At the same time, the main control board sends focusing information to the focusing unit, so that the focal position can be readjusted until focusing is completed.

[0032] In this way, the light beam emitted by the light output unit 11 and the output fiber pigtail can be adaptively coupled without disassembling the original light output unit 11 or removing some optical components in the light output unit 11. This application not only simplifies the repair process, but also allows the light output unit 11 to be reused, reducing the replacement frequency of the light output unit 11 and greatly reducing production costs.

[0033] The laser of the present application will now be explained in further detail with reference to the following embodiments.

[0034] Specifically, the focusing unit 12 includes a first wedge-shaped mirror and a second wedge-shaped mirror, which are sequentially arranged along the optical axis of the light beam and are centrally symmetrically arranged. The exit surface of the first wedge-shaped mirror corresponds to the exit surface of the second wedge-shaped mirror.

[0035] In this embodiment, both the first wedge-shaped mirror and the second wedge-shaped mirror are rhombic prisms.

[0036] It can be understood that when the two wedge-shaped mirrors are adjusted to be separated by a preset distance along the optical axis of the light beam, and / or at least one of them is moved along its inclined surface, and / or the first wedge-shaped mirror and the second wedge-shaped mirror are synchronously rotated at a predetermined angle along the optical axis, the light beam emitted from the light emitting unit 11 is focused at a preset position after passing through the focusing unit 12.

[0037] The present application adds a focusing unit 12 with two wedge-shaped mirrors inside the pump source 1. When the old output fiber pigtail is damaged, a new output fiber pigtail can be directly connected. By changing the relative positions of the two wedge-shaped mirrors, the optical path is changed to achieve focus adjustment. The optical path can be rebuilt without replacing some optical components inside the pump source 1, thereby ensuring the light beam coupling efficiency of the new output fiber pigtail and reducing maintenance costs.

[0038] Specifically, the focusing unit 12 further includes an adjusting member 13 , which is connected to the first wedge-shaped mirror and the second wedge-shaped mirror and controls the first wedge-shaped mirror and the second wedge-shaped mirror.

[0039] In one embodiment, the adjusting member 13 is used to adjust the distance between the first wedge-shaped mirror and the second wedge-shaped mirror in the light beam exit direction. Figure 8 and Figure 10 It can be understood that by moving at least one of the two wedge-shaped mirrors a preset distance along the light beam emission direction through the adjustment member 13, the optical path of the light beam emitted from the light emitting unit 11 can be changed, thereby achieving the adjustment of the focal position.

[0040] In one embodiment, the adjusting member 13 further causes the first wedge-shaped mirror and the second wedge-shaped mirror to be partially offset in the extending direction of their inclined surfaces. Figure 7 and Figure 8 It can be understood that, after the installation state of the new output fiber pigtail is fixed, at least one of the first wedge-shaped mirror and the second wedge-shaped mirror is relatively moved by a preset distance along the extending direction of the inclined surfaces thereof by the adjusting member 13, thereby changing the optical path of the light beam emitted from the light output unit 11 until the optical axis of the light beam corresponds to the core of the new output fiber pigtail, and the light beam is completely coupled into the new output fiber pigtail.

[0041] In one embodiment, the adjustment member 13 further controls any one of the first wedge-shaped mirror and the second wedge-shaped mirror to rotate at a predetermined angle along the optical axis of the light beam, thereby changing the optical path of the light beam emitted from the light output unit 11 and adjusting the focal position.

[0042] Specifically, the first and second wedge-shaped mirrors can be synchronously rotated at a predetermined angle along the optical axis, thereby also achieving the purpose of adjusting the focal position. It will be understood that in this embodiment, when the wedge-shaped mirror assembly rotates about the optical axis, the focal position of the light beam changes in a direction perpendicular to the optical axis.

[0043] In an embodiment of the present application, the focusing unit further includes a driving mechanism connected to the adjusting member and electrically connected to the main control board, for controlling the adjusting member to drive the first wedge mirror and / or the second wedge mirror to move according to a control signal from the main control board.

[0044] It is understandable that when focusing is not completed, the signal processing unit sends the judgment result to the main control board, the main control board sends a control signal, and the driving mechanism controls the adjustment member to drive the first wedge mirror and / or the second wedge mirror to move according to the control signal until the diameter of the focal spot is equal to the preset diameter, and the measured center point position of the spot is consistent with the preset center point position, and the coupling of the light beam and the output fiber pigtail is completed.

[0045] Please refer to Figure 2 The focusing unit 12 further includes a cylindrical lens group 14, which is arranged before the incident surface of the first wedge-shaped mirror and is used to converge the incident light beam.

[0046] In one embodiment, the pump source 1 housing includes an output fiber pigtail coupling port 20 for mounting an output fiber pigtail. The end face of the output fiber pigtail is aligned with the exit surface of the second wedge-shaped mirror via the output fiber pigtail coupling port 20. It is understood that the cross-sectional area of ​​the output fiber pigtail coupling port 20 is greater than the radial cross-sectional area of ​​the output fiber pigtail. In other words, when the output fiber pigtail is not secured to the output fiber pigtail coupling port using solder, a clamp, or other fixture, the output fiber pigtail is movable. Therefore, after a new output fiber pigtail is replaced and secured, the pump source of the present application can achieve aligned coupling of the light beam with the core of the output fiber pigtail by adjusting the focusing unit 12.

[0047] For details, please refer to Figure 8 When the inclined surfaces of the first wedge-shaped mirror and the second wedge-shaped mirror are completely aligned and the two wedge-shaped mirrors are arranged in a centrally symmetrical manner, the light beam emitted from the pump source 1 is focused at the first preset position 23 and is coupled to the output fiber pigtail at the first preset position 23 connected to the output fiber pigtail coupling port 20.

[0048] Please refer to Figure 10 , relative to Figure 8In the position shown, when at least one of the two wedge-shaped mirrors moves a preset distance along the light beam emission direction, the light beam emitted from the pump source is focused at the third preset position 25, and is just coupled to the output fiber pigtail at the third preset position 25 connected to the output fiber pigtail coupling port 20.

[0049] Please refer to Figure 9 When the two wedge-shaped mirrors are partially offset in the extension direction of their inclined surfaces, the light beam emitted from the pump source 1 is focused at the second preset position 24, and is just coupled with the output fiber pigtail at the second preset position 24 connected to the output fiber pigtail coupling port 20.

[0050] It is understandable that the adjustment member 13 of the present application provides at least two ways of adjusting the focus along the extension direction of the optical axis and one way of adjusting the focus position along the direction perpendicular to the optical axis. The first preset position 23 is different from the second preset position 24, and the first preset position 23 is different from the third preset position 25. Furthermore, it can be seen that when the input end of the output fiber pigtail is docked with different areas on the output fiber pigtail coupling port 20, the focusing unit 12 can be adjusted to zoom the light beam emitted from the light output unit 11, so that the optical axis of the light beam coincides with the core 21 of the output fiber pigtail.

[0051] In actual use, the output fiber pigtail is installed in the armored cable 2. The light beam output from the pump source is amplified after passing through the armored cable 2, forming a laser. In other words, the armored cable 2 not only protects the output fiber pigtail, transmits the laser light, and absorbs and amplifies the pump light, but this design also eliminates the need to replace certain optical components within the pump source 1 if the armored cable 2 is damaged, significantly reducing laser maintenance costs. It can be understood that the armored cable 2 is installed at the beam output end of the pump source, specifically through the output fiber pigtail coupling port on the pump source 1 housing. The light beam emitted by the light output unit 11 passes through the focusing unit 12 and is then coupled into the armored cable 2.

[0052] Optionally, the output pigtail in the armored cable 2 is a multi-clad single-core active output pigtail or a multi-core active output pigtail.

[0053] In this embodiment, please refer to Figure 4 or Figure 5 The output pigtail in the output pigtail armored cable 2 is a multi-clad single-core active output pigtail, that is, it has a single fiber core 21 and at least one inner cladding 22 directly coated on the fiber core 21. The output pigtail is a doped output pigtail, that is, both the fiber core 21 and the inner cladding 22 are doped with gain ions to improve the gain performance of the output pigtail.

[0054] The present application directly uses the armored cable 2 with the above-mentioned output fiber to replace the energy transmission fiber and gain fiber of the traditional laser, and directly assembles it into the output fiber coupling port of the pump source, and etches the fiber grating on its output fiber. Therefore, there is no need to re-melt the bundler and redundant optical devices, which greatly reduces the fusion point and the power loss caused by the fusion point.

[0055] Optionally, the gain ions in the output pigtail are any one of ytterbium, erbium, neodymium or thulium.

[0056] In this embodiment, please continue to refer to Figure 2 and Figure 6 The output fiber of the output fiber armor cable 2 is sequentially engraved with a first grating group 3 and a second grating group 4. The first grating group 3 includes a first cladding grating 31 and a first core grating 32. The second grating group 4 includes a second core grating 42 and a second cladding grating 41. Figure 3 and Figure 4 As shown, the first cladding grating 31 and the second cladding grating 41 are arranged on the inner cladding 22 , and the first core grating 32 and the second core grating 42 are arranged on the core 21 .

[0057] It can be understood that the first core grating 32, the second core grating 42, and the gain ion-doped output pigtail constitute the optical resonant cavity of the laser. After the pump light emitted by the pump source 1 enters the output pigtail in the armored cable 2, a portion of the pump light enters the core 21, while another portion enters the inner cladding 22. The pump light that enters the core 21 is absorbed after passing through the resonant cavity and becomes signal light. The remaining pump light, after gain generation in the inner cladding 22, generates an intermediate wave. This intermediate wave is reflected by the first cladding grating 31 and the second cladding grating 41 in the inner cladding 22, unable to escape from the inner cladding 22. Instead, it refracts into the core 21 and is reabsorbed by the resonant cavity. The design of the cladding grating and the core grating eliminates the need for a cladding light filter to be fused into the optical path. Furthermore, the cladding grating group reflects the pump light that is not fully absorbed by the resonant cavity and reabsorbs it within the resonant cavity. Under the same absorption efficiency, the effective length of the resonant cavity (i.e., the length of the output fiber pigtail within the cavity) is shorter than that without the cladding grating group. This structure achieves low-cost, high-power signal light output.

[0058] In other embodiments, the output fiber pigtail may have a single cladding, a double cladding, or other multiple claddings, which may be determined according to the actual needs of the laser. When the output fiber pigtail is a double-cladding output fiber pigtail, a cladding light filter is provided between the output end of the output fiber pigtail and the grating in the second grating group 4 that is away from the first grating group 3, or a group of high-reflectivity cladding gratings is etched on the outer cladding of the output fiber pigtail, which can also achieve the effect of stripping the cladding light or reusing the cladding light. Similarly, when the output fiber pigtail is a multi-cladding grating, a cladding light filter is provided between the output end of the output fiber pigtail and the grating in the second grating group 4 that is away from the first grating group 3, or a group of high-reflectivity cladding gratings is etched on each cladding of the armored cable 2.

[0059] In other embodiments, the output pigtail in the armored cable 2 can also be a multi-core active fiber, which has multiple cores with different diameters, so that the converging light beam of a predetermined wavelength can be accurately coupled into the core of the corresponding diameter, thereby realizing the distribution of the light beam to the predetermined core according to the actual needs of the laser.

[0060] When the output pigtail is a single-clad multi-core active fiber, the first cladding grating 31 and the second cladding grating 41 are arranged on the output pigtail, that is, they are simultaneously engraved on the cladding and multiple cores; and the first core grating 32 is written in the predetermined core of the output pigtail, and the second core grating 42 is written in the predetermined core of the output pigtail. At this time, the first core grating 32 is the input end of the resonant cavity, and the second core grating 42 is the output end of the resonant cavity.

[0061] It can be understood that in other embodiments, the light beam emitted from the light output unit 11 is converged and focused by the focusing unit 12, and then directly coupled to the predetermined fiber core of the multi-core active output fiber pigtail, thereby generating a single laser beam emitted from the predetermined fiber core of the multi-core active output fiber pigtail.

[0062] Please continue to refer to Figure 2 The output end of the output fiber pigtail is fused and connected to the laser output head 5. In other embodiments, the output end of the output fiber pigtail can also be directly connected to the laser output head.

[0063] Preferably, the laser reflectivity of the first cladding grating 31 , the first core grating 32 , and the second cladding grating 41 are all higher than the laser reflectivity of the second core grating 42 .

[0064] Specifically, the reflectivity of the high-reflectivity grating, that is, the laser reflectivity of the first cladding grating 31, the first core grating 32, and the second cladding grating 41 is greater than 99%; the reflectivity of the low-reflectivity grating, that is, the second core grating 42 is less than 20%. No relative size limitation is imposed on the laser reflectivity of the first cladding grating 31, the first core grating 32, and the second cladding grating 41.

[0065] Alternatively, in one embodiment, please refer to Figure 2 and Figure 6 The grating arrangement positions shown are: the first cladding grating 31, the first core grating 32, the second core grating 42 and the second cladding grating 41.

[0066] Alternatively, in another embodiment, please refer to Figure 3 and Figure 7 The grating arrangement positions shown are: the first core grating 32, the first cladding grating 31, the second cladding grating 41 and the second core grating 42.

[0067] Optionally, the operating wavelengths of the first cladding grating 31 and the second cladding grating 41 are consistent, both are 915 nm or both are 976 nm; the operating wavelengths of the first core grating 32 and the second core grating 42 are consistent, both are 1064 nm; and the output light wavelength of the pump source 1 is 915 nm or 976 nm.

[0068] The technical solution of the present application has the following advantages: for a method for quickly replacing a low-power laser output fiber pigtail, when the laser output fiber pigtail is damaged, the method proposed in the present application can directly realize the rapid replacement of the output fiber pigtail and its coupling with the light beam, while ensuring a high light beam coupling efficiency without having to replace some optical components inside the laser pump source, thereby greatly reducing maintenance costs; For lasers that can replace their output pigtails using the aforementioned method, the laser of the present application adds a focusing unit comprising a first wedge-shaped mirror and a second wedge-shaped mirror to the pump source. When the optical fiber armor cable is damaged, the relative position of the two wedge-shaped mirrors can be directly changed via an adjustment member connected to the drive mechanism, thereby changing the optical path to achieve focus adjustment and thus ensuring beam coupling efficiency. Compared to the prior art method that requires directly replacing some healthy components in the pump source and the damaged optical fiber once the optical fiber is damaged, the present application eliminates the need to replace internal optical components in the event of optical fiber damage, thus reducing production costs.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Based on the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present application as described above. For the sake of simplicity, they are not provided in detail. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for quickly replacing a low-power laser output fiber pigtail, which is applied to the repair of a low-power laser with a damaged output fiber pigtail, characterized in that: The following steps are involved: S1. Install a new output pigtail and emit a light beam to the new output pigtail; S2, collecting a focal spot image of the light beam; S3, judging whether the light beam is focused on the new output fiber according to the light spot image information; S4. Adjust the focus of the light beam according to the judgment result, so that the output fiber pigtail is coupled with the light beam and the focus is completed.

2. The method for quickly replacing a low-power laser output pigtail according to claim 1, characterized in that: The light spot image information includes the measured diameter of the light spot and the measured center point position information of the light spot.

3. The method for quickly replacing a low-power laser output pigtail according to claim 2, characterized in that: When the measured diameter of the light spot is equal to the preset diameter, and the measured center point position of the light spot is consistent with the preset center point position, it is determined that the focusing is completed.

4. The method for quickly replacing a low-power laser output pigtail according to claim 2, characterized in that: When the measured diameter of the light spot is not equal to the preset diameter, and / or the measured center point position of the light spot is inconsistent with the preset center point position, it is determined that the focus is not completed, and the focus of the light beam is adjusted until the focus is completed.

5. A laser, wherein the pump source of the laser is connected to the laser output head via the output pigtail, and the output pigtail is replaced by the method for quickly replacing the low-power laser output pigtail according to any one of claims 1 to 4, characterized in that: The laser comprises: a light emitting unit, the light emitting unit being arranged inside the pump source for emitting a light beam; A focusing unit is provided along the light-emitting direction of the light beam and is also provided inside the pump source to adjust the focal position of the light beam; An image acquisition unit, configured to acquire a spot image of the light beam after focusing; a signal processing unit, the signal processing unit being electrically connected to the image acquisition unit and configured to determine whether the output pigtail is focused based on the light spot image information; A main control board is electrically connected to the signal processing unit. The signal processing unit is further configured to send a judgment result to the main control board. The main control board controls whether the focusing unit focuses or not according to the judgment result.

6. The laser according to claim 5, characterized in that The focusing unit comprises: First wedge mirror; a second wedge-shaped mirror, wherein the first wedge-shaped mirror and the second wedge-shaped mirror are sequentially arranged along the optical axis of the light beam and are centrally symmetrically arranged, and an exit surface of the first wedge-shaped mirror corresponds to an incident surface of the second wedge-shaped mirror; an adjusting member connected to the first wedge-shaped mirror and the second wedge-shaped mirror, and configured to adjust a distance between the first wedge-shaped mirror and the second wedge-shaped mirror along the optical axis, and / or move at least one of the first wedge-shaped mirror and the second wedge-shaped mirror along an extending direction of an incident surface of the first wedge-shaped mirror, and / or rotate at least one of the first wedge-shaped mirror and the second wedge-shaped mirror at a predetermined angle along the optical axis; and a driving mechanism, wherein the driving mechanism is connected to the adjusting member and electrically connected to the main control board, so as to control the adjusting member to drive the first wedge-shaped mirror and / or the second wedge-shaped mirror to move according to a control signal sent by the main control board.

7. The laser according to claim 5, characterized in that An output fiber pigtail coupling port is provided on the pump source, and the output fiber pigtail coupling port is provided on the light-emitting side of the focusing unit for assembling the output fiber pigtail.

8. The laser according to claim 6, characterized in that The focusing unit further includes a cylindrical lens group, which is arranged in front of the incident surface of the first wedge-shaped mirror to converge the incident light beam.

9. The laser according to claim 6, characterized in that The output pigtail is installed in the armored cable, and the light beam output from the pump source is amplified by the gain after passing through the armored cable to form a laser.

10. The laser according to claim 9, characterized in that The output fiber pigtail is sequentially engraved with a first grating group and a second grating group, the first grating group includes a first cladding grating and a first core grating, and the second grating group includes a second core grating and a second cladding grating; the reflectivity of the first cladding grating, the first core grating and the second cladding grating for laser light in a predetermined wavelength band is higher than the reflectivity of the second core grating for laser light in the predetermined wavelength band.

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