Fiber laser and laser processing equipment

Abstract

The invention discloses an optical fiber laser and laser processing equipment, which are provided with a laser module for outputting a laser beam, a guide light module for outputting a guide light beam, a wavelength division multiplexer for connecting the laser module and the guide light module, and a reflection module positioned between the guide light module and the wavelength division multiplexer, the wavelength division multiplexer is used for converging the laser beam and the guiding light beam and guiding the laser beam to machine the workpiece to be machined through the guiding light beam, and the reflection module is at least used for reflecting a return light beam formed when the laser beam machines the workpiece to be machined. And furthermore, the reflection module arranged in the application can reflect the return light, so that the damage of the return light to the guide light module is reduced.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, and in particular to a fiber laser and laser processing equipment. Background Art

[0002] In the related art, the red light emitted by the red light source is used as an indicator light in the fiber laser. Before marking a material with high reflectivity, the indicator light emits an indicator light to replace the laser to confirm the starting position of the marking. When marking, the indicator light is turned off and the laser is output to engrave the material. However, the problem is that since the material with high reflectivity will generate reflected light when engraving, the reflected light will enter the interior of the laser along the laser output port and damage the internal red light source. As a result, the indicator light is damaged and fails or the indicator light power is weak, and it does not play the role of the indicator light. Summary of the invention

[0003] The invention provides a fiber laser and laser processing equipment to reduce the influence of return light on the indicator light laser in the related art.

[0004] According to one aspect of the present invention, there is provided a fiber laser, comprising:

[0005] A laser module, used for outputting a laser beam;

[0006] A guiding light module, used for outputting a guiding light beam;

[0007] A wavelength division multiplexer, used to connect the laser module and the guiding light module, and used to merge the laser beam and the guiding light beam;

[0008] The reflection module is arranged between the guiding light module and the wavelength division multiplexer, and the reflection module is at least used to reflect the return light beam formed when the laser beam processes the workpiece.

[0009] Optionally, the reflection module is a processing light reflection module, the period of the processing light reflection module is determined by the wavelength of the returning light beam and the effective refractive index of the processing light reflection module, and the processing light reflection module is also used to ensure that the difference between the output power of the guiding light module and the working power of the guiding light beam is within a preset range, wherein the processing light reflection module is a fiber Bragg grating.

[0010] Optionally, the laser module comprises a resonant cavity and an amplifier stage;

[0011] The wavelength division multiplexer is located inside the resonant cavity, or between the resonant cavity and the amplifier stage.

[0012] Optionally, when the output power of the resonant cavity is greater than or equal to the damage threshold of the wavelength division multiplexer and the power inside the resonant cavity is less than the damage threshold of the wavelength division multiplexer, the wavelength division multiplexer is located inside the resonant cavity;

[0013] When the output power of the resonant cavity is less than the damage threshold of the wavelength division multiplexer and the power inside the resonant cavity is greater than the damage threshold of the wavelength division multiplexer, the wavelength division multiplexer is located between the resonant cavity and the amplification stage.

[0014] Optionally, the laser module further includes a first pump unit, a first gain fiber, and a resonant cavity. The resonant cavity includes a first fiber Bragg grating and a second fiber Bragg grating that form relative reflection. Among them,

[0015] The output end of the first pump unit is connected to the resonant cavity through an optical fiber combiner, and the first gain fiber is arranged inside the resonant cavity;

[0016] When the wavelength division multiplexer is located inside the resonant cavity, the first end of the wavelength division multiplexer is connected to the first fiber Bragg grating, the second end is connected to the first gain fiber, and the third end is connected to the input end of the return light beam of the reflection module;

[0017] When the wavelength division multiplexer is located between the resonant cavity and the amplification stage of the laser module, the first end of the wavelength division multiplexer is connected to the output end of the resonant cavity, the second end is connected to the amplification stage, and the third end is connected to the input end of the return light beam of the reflection module.

[0018] Optionally, the resonant cavity further includes a Q-switch, and the Q-switch is located between the first fiber Bragg grating and the first gain fiber.

[0019] Optionally, the amplification stage of the laser module includes a second pump unit, a second optical fiber combiner, and a second gain fiber;

[0020] One side of the second optical fiber combiner is used to connect the second pump unit and the output end of the resonant cavity of the laser module, and the other side is used to connect the second gain fiber. The other end of the second gain fiber is used to output the laser beam and the guiding light beam.

[0021] Optionally, the reflection module further includes a pump light reflection module, and the pump light reflection module is arranged between the processing light reflection module and the guiding light module, or arranged between the processing light reflection module and the wavelength division multiplexer. Among them, the pump light reflection module is a fiber Bragg grating.

[0022] Optionally, the guiding light module is one of a red light source, a green light source, a purple light source, or a blue light source.

[0023] According to another aspect of the present invention, an embodiment of the present invention further provides a laser processing device, including an optical fiber laser as described in any embodiment of the present invention.

[0024] In the technical solution of the embodiment of the present invention, a reflection module is arranged on the transmission path of the guiding light module, and the reflection module is at least used to reflect the return light beam formed when the laser beam processes the workpiece to be processed. Furthermore, the reflection module provided in the present application can reflect the return light to avoid the return light generated when engraving a material with a high reflectivity from entering the inside of the laser through the laser output port and damaging the internal red light source. That is, the reflection module can weaken the influence of the return light on the guiding light module to improve the performance of the guiding light module.

[0025] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 is a block diagram of the optical fiber laser provided in the embodiment of the present invention;

[0028] Figure 2 is a block diagram of the optical fiber laser provided in an embodiment of the present invention;

[0029] Figure 3 is a block diagram of the optical fiber laser provided in another embodiment of the present invention;

[0030] Figure 4 is a block diagram of the optical fiber laser provided in yet another embodiment of the present invention;

[0031] Figure 5 is a schematic optical path diagram of the optical fiber laser provided in the embodiment of the present invention;

[0032] Figure 6 is a schematic optical path diagram of the optical fiber laser provided in an embodiment of the present invention;

[0033] Figure 7 is a schematic optical path diagram of the optical fiber laser provided in another embodiment of the present invention;

[0034] Figure 8 It is the optical path schematic diagram of the fiber laser provided in another embodiment of the present invention;

[0035] Figure 9 It is the optical path schematic diagram of the fiber laser provided in yet another embodiment of the present invention.

[0036] Reference numerals: 100, fiber laser; 101, laser module; 102, guiding light module; 103, wavelength division multiplexer; 104, reflection module; 105, workpiece to be processed; 1011, resonator; 1012, amplification stage; 106, first pump unit; 107, first fiber combiner; 108, first gain fiber; 109, first fiber Bragg grating; 110, second fiber Bragg grating; 111, second pump unit; 112, third pump unit; 113, second fiber combiner; 114, second gain fiber; 115, pump light reflection module; 116, Q-switch; 1041, processing light reflection module. Detailed implementation manners

[0037] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order different from those illustrated or described here. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0039] Figure 1 It is the block diagram of the fiber laser provided in the embodiment of the present invention. Figure 2 It is the block diagram of the fiber laser provided in the embodiment of the present invention; as Figure 1 and Figure 2 shown, the fiber laser 100 includes:

[0040] Laser module 101, for outputting a laser beam;

[0041] Guide light module 102, for outputting a guide light beam;

[0042] Wavelength division multiplexer 103, for connecting the laser module 101 and the guide light module 102, for combining the laser beam and the guide light beam, so as to guide the laser beam to process the workpiece 105 through the guide light beam;

[0043] Reflection module 104, respectively connected to the guide light module 102 and the wavelength division multiplexer 103, and the reflection module 104 is used to at least reflect the return light beam formed when the laser beam processes the workpiece 105.

[0044] It can be understood that the laser module 101 can be a continuous laser or a pulsed laser. It is mainly selected adaptively according to the processing method of the workpiece 105. Exemplarily, continuous lasers are mainly used for metal cutting, welding or drilling, etc., and pulsed lasers are mainly used for laser marking, etc.

[0045] The guide light module 102 can be a visible light laser. Exemplarily, for example, it can be a red light source, a green light source, a purple light source or a blue light source. In order to better guide the laser output by the laser module 101, a red light source is usually used in actual working conditions.

[0046] The wavelength division multiplexer 103 is located inside the laser module 101 (as Figure 1 shown) or outside the laser module 101 (as Figure 2 shown), can connect the laser module 101 and the guide light module 102, and can combine the guide light beam into the laser beam, and then act on the workpiece 103 simultaneously.

[0047] The working principle of the above-mentioned fiber laser 100 is as follows: The wavelength division multiplexer 103 converges the guiding light beam into the laser beam, so that the guiding light beam is mixed in the laser beam output by the laser module 101. Furthermore, during the processing of the workpiece 105 to be processed, the guiding light beam and the laser beam act on the workpiece 105 together, and the spot position of the laser beam output by the laser module 101 can be adjusted according to the position of the guiding light beam and the processing requirements of the workpiece 105. Among them, during the processing of the workpiece 105, a retroreflected light beam will be generated for the laser beam, and this retroreflected light beam will return to the guiding light module 102 after passing through the optical fiber and the wavelength division multiplexer 103 in the laser module 101. In this application, the reflection module 104 is used to reflect the retroreflected light beam to prevent the retroreflected light beam from touching the guiding light module 102, causing damage such as heat generation of the guiding light module 102. Thus, the reflection module provided in this application can reflect the retroreflected light to prevent the retroreflected light generated during the engraving of high-reflectivity materials from entering the inside of the laser through the laser output port and damaging the internal red light source, that is, the reflection module can weaken the influence of the retroreflected light on the guiding light module to improve the performance of the guiding light module.

[0048] Optionally, the reflection module 104 includes a processing light reflection module 1041. The processing light reflection module 1041 is a fiber Bragg grating for reflecting the retroreflected light. The period of the fiber Bragg grating is determined by the wavelength of the retroreflected light beam and the effective refractive index of the fiber Bragg grating. The processing light reflection module 1041 is also used to ensure that the difference between the output power of the guiding light module and the working power of the guiding light beam is within a preset range.

[0049] That is to say, by setting the reflection module 104 as a Bragg grating. There are periodic or aperiodic perturbations of the effective refractive index in the fiber core of this Bragg grating. Under this periodic / aperiodic perturbation of the effective refractive index, when the Bragg condition is satisfied, light (propagating along the optical fiber) is reflected within a narrow wavelength range. Among them, the Bragg condition formula is λ = 2nΛ, where λ is the wavelength of the reflected light in vacuum, Λ is the grating period, and n is the effective refractive index of the optical fiber. Thus, according to this Bragg formula condition, light of other wavelengths does not satisfy the Bragg condition and is hardly affected by the Bragg grating. Therefore, this Bragg grating is used to reflect the light for processing applications and does not affect the output light wavelength of the indicator light red light, in other words, it does not affect the power of the red light source. It should be noted that the processing light reflection module 1041 is a main wavelength grating with a reflectivity of 99.5% (i.e., the wavelength of the retroreflected light of the laser beam finally output by the laser module 101, generally 1064 nm).

[0050] Therefore, the reflection module 104 can ensure that the output power of the guiding light module 102 is almost unaffected during the reflection of the returning light beam. It can also be understood that the returning light attenuator 104 can ensure that the difference between the output power of the guiding light module 102 and the working power of the guiding light beam is within a preset range.

[0051] That is to say, the reflection module 104 attenuates the return light beam alone, and does not attenuate the power of the guide light beam, that is, it does not affect the normal function of the guide light module 102. Furthermore, the guide light module 102 will not cause the indicator light to be damaged or ineffective, or the indicator light power is weak, and it does not play the role of the indicator light. Therefore, the reflection module 104 attenuates the return light beam, avoiding the return light beam from damaging the guide light module 102, and at the same time, it can completely pass the guide light beam without attenuating the guide light beam, thereby ensuring the output power of the guide light module 102 and extending the life of the fiber laser.

[0052] In another embodiment, the return light may be further attenuated by winding a coil around the pigtail of the guiding light module 102 , and the coil is located between the guiding light module 102 and the reflection module 104 .

[0053] Figure 3 is a block diagram of a fiber laser provided in another embodiment of the present invention; Figure 4 is a block diagram of a fiber laser provided in another embodiment of the present invention. Figure 3 and Figure 4 As shown, the laser module 101 includes a resonant cavity 1011 and an amplifier stage 1012;

[0054] The wavelength division multiplexer 103 is located inside the resonant cavity 1011 , or between the resonant cavity 1011 and the amplifier stage 1012 .

[0055] It is understandable that the laser module 101 is mainly composed of a resonant cavity 1011 and an amplifier stage 1012. In order to use the light output by the guide light module 102 as the guide light in the laser system, a wavelength division multiplexer 103 (WDM) needs to be added to the laser module 101. The function of the WDM is to multiplex optical signals of different wavelengths into the same optical fiber for transmission, thereby achieving the coexistence of the guide light and the main wavelength of the laser.

[0056] The design and placement of the WDM need to be determined based on the energy it can withstand. This is because the WDM may be affected by high-energy optical signals during operation. If its tolerance is insufficient, it may lead to device damage or performance degradation. Therefore, during system design, the placement of the WDM must be reasonably selected according to the output power of the laser module 101, the power of the guiding optical module 102, and the rated energy tolerance of the WDM to ensure the stable operation and efficient transmission of the system.

[0057] Exemplarily, when the output power of the resonant cavity 1011 is greater than or equal to the damage threshold of the wavelength division multiplexer 103, and the power inside the resonant cavity 1011 is less than the damage threshold of the wavelength division multiplexer 103, the wavelength division multiplexer 103 is located inside the resonant cavity 1011; when the output power of the resonant cavity 1011 is less than the damage threshold of the wavelength division multiplexer 103, and the power inside the resonant cavity 1011 is greater than the damage threshold of the wavelength division multiplexer 103, the wavelength division multiplexer 103 is located between the resonant cavity 1011 and the amplification stage 1012. That is to say, when the output power of the resonant cavity 1011 is less than the damage threshold of the wavelength division multiplexer 103, and the power inside the resonant cavity 1011 is greater than the damage threshold of the wavelength division multiplexer 103, in order to ensure the normal function of the wavelength division multiplexer 103 and avoid the energy of the resonant cavity 1011 causing significant damage to the wavelength division multiplexer 103, furthermore, the wavelength division multiplexer 103 is arranged between the resonant cavity 1011 and the amplification stage 1012. Conversely, the wavelength division multiplexer 103 can be arranged inside the resonant cavity 1011, and if both are within the damage threshold, it can be selected and arranged to balance the optical performance.

[0058] When the wavelength division multiplexer 103 is located inside the resonant cavity 1011, the wavelength division multiplexer 103 can avoid the high temperature of the master oscillator laser emitted from the resonant cavity 1011. When the wavelength division multiplexer 103 is located between the resonant cavity 1011 and the amplification stage 1012, the wavelength division multiplexer 103 will not affect the length of the resonant cavity 1011.

[0059] Figure 5 It is the optical path schematic diagram of the fiber laser provided in the embodiment of the present invention. Optionally, as Figure 5 shown, the laser module 10 includes a first pump unit 106, a first gain fiber 108, and a resonant cavity 1011 arranged in sequence along the first pump light transmission direction. The resonant cavity 1011 includes a first fiber Bragg grating 109 that forms opposite reflections;

[0060] The output end of the first pump unit 106 is connected to the resonant cavity 1011 through a first fiber combiner 107, and the first gain fiber 108 is arranged inside the resonant cavity 1011.

[0061] When the wavelength division multiplexer 103 is located inside the resonant cavity 1011, the first end of the wavelength division multiplexer 103 is connected to the first fiber Bragg grating 109, the second end is connected to the first gain fiber 108, and the third end is connected to the return light beam input end of the reflection module 104;

[0062] When the wavelength division multiplexer 103 is located between the resonant cavity 1011 and the amplification stage 1012 of the laser module 101, the first end of the wavelength division multiplexer 103 is connected to the output end of the resonant cavity 1011, the second end is connected to the amplification stage 1012, and the third end is connected to the return light beam input end of the reflection module 104.

[0063] Among them, the first fiber Bragg grating 109 and the second fiber Bragg grating 110 form a pair of reflecting mirrors, which can enable the first pump beam of the first pump unit 106 to be reflected back and forth between them to form a resonant cavity. The first fiber Bragg grating 109 is a high-reflectivity grating with a reflectivity greater than 99% (preferably greater than 99.5%), and the second fiber Bragg grating 110 is a low-reflectivity grating with a reflectivity of 10%-50% (preferably 10%).

[0064] It can be understood that the first pump unit 106 outputs the first pump beam, which enters the gain fiber 108 through the first fiber coupler 107, then reaches the first fiber Bragg grating 109 through the wavelength division multiplexer 103, and after being reflected by the first fiber Bragg grating 109, it reaches the second fiber Bragg grating 110 along the reverse path. Part of the first pump beam is output to the amplification stage 1012 by the second fiber Bragg grating 110 after being amplified by the resonant cavity gain, and part of the first pump beam is reflected back to the resonant cavity 1011 by the second fiber Bragg grating 110 along the original pump path.

[0065] Figure 6 It is the optical path schematic diagram of the fiber laser provided in the embodiment of the present invention. Since when the first pump beam resonates in the resonant cavity 1011, it will pass through the wavelength division multiplexer 103. If the pump beam is not fully absorbed by the first gain fiber 108, it may contact the guiding light module 102 along the pigtail of the guiding light module 102, thereby affecting the normal operation of the guiding light module 102. Therefore, the reflection module 104 further includes a pump light reflection module 115, and the pump light reflection module 115 (as Figure 6 shown) is arranged between the reflection module 104 and the wavelength division multiplexer 103 to reflect the pump beam not absorbed by the gain fiber. Among them, the pump light reflection module 115 can be a reflection pump wavelength grating with a reflectivity of 99.5%.

[0066] Figure 7 It is the optical path schematic diagram of the fiber laser provided in another embodiment of the present invention. Optionally, as Figure 7As shown, the resonant cavity 101 further includes a Q-switch 116, and the Q-switch 116 is located between the first fiber Bragg grating 109 and the first gain fiber 108.

[0067] It can be understood that when the wavelength division multiplexer 103 is inside the resonant cavity 1011, the Q-switch 116 can be connected to the first fiber Bragg grating 109 and the wavelength division multiplexer 103 respectively, or connected to the wavelength division multiplexer 103 and the first gain fiber 108 respectively. When the wavelength division multiplexer 103 is between the resonant cavity 1011 and the amplification stage 1012, the Q-switch 116 is connected to the first fiber Bragg grating 109 and the first gain fiber 108 respectively (as Figure 7 shown).

[0068] Among them, the addition of the Q-switch 116 can obtain pulsed laser to adapt to the processing methods of different workpieces 105 to be processed.

[0069] Figure 8 is the optical path schematic diagram of the fiber laser provided in another embodiment of the present invention; Figure 9 is the optical path schematic diagram of the fiber laser provided in another embodiment of the present invention. Optionally, as Figures 5 to 9 shown, the amplification stage 1012 of the laser module 101 includes a second pump unit 111, a second fiber combiner 113 and a second gain fiber 114;

[0070] One side of the second fiber combiner 113 is used to connect the second pump unit 111 and the output end of the resonant cavity 1011 of the laser module 101, and the other side is used to connect the second gain fiber 114. The other end of the second gain fiber 114 is used to output the laser beam and the guiding light beam.

[0071] Among them, as Figures 5 to 7 shown, the wavelength division multiplexer 103 is inside the resonant cavity 1011. Furthermore, the guiding light beam is mixed in the main oscillation beam output by the resonant cavity 1011. Then, the main oscillation beam and the guiding light beam enter the amplification stage 1012 simultaneously, and after being amplified by the second gain fiber 114, they are output and act on the workpiece 105 to be processed at the same time.

[0072] As Figure 8 and Figure 9 shown, the wavelength division multiplexer 103 is between the resonant cavity 1011 and the amplification stage 1012. After the main oscillation beam output by the resonant cavity 1011 and the guiding light beam are mixed, they enter the amplification stage 1012 simultaneously, and after being amplified by the second gain fiber 114, they are output and act on the workpiece 105 to be processed at the same time. In Figure 9In the example, a pump light reflection module 115 is also added to avoid the influence of the pump light of the second pump unit 111 on the guiding light module 102. A Q-switch 116 is also added to form a pulsed laser.

[0073] In another embodiment, the amplification stage 1012 may further include a third pump unit 112.

[0074] A winding module may be additionally provided in the reflection module 104 and can be used in combination with two gratings (i.e., the pump light reflection module 115 and the processing light reflection module 1041). For example, when processing materials, a photochemical reaction occurs, generating light other than the signal light (1064 nm) and the pump light (915 nm).

[0075] In the above embodiment, the first fiber combiner 107 is a (1 + 1)*1 combiner, and the second fiber combiner 113 is a (1 + 2)*1 combiner. The first gain fiber 108 and the second gain fiber 114 may be solid-state gain media (such as neodymium-doped yttrium aluminum garnet (Nd:YAG), ytterbium-doped yttrium aluminum garnet (Yb:YAG), titanium dioxide (TiO2), etc.). The periods of the first fiber Bragg grating 109 and the second fiber Bragg grating 110 are mainly determined by the first pump beam output by the first pump unit 106. The pump light reflection module 115 determines the corresponding returned pump light according to the position of the wavelength division multiplexer 103, and it is also a fiber Bragg grating.

[0076] According to another aspect of the present invention, an embodiment of the present invention further provides a laser processing device, including the fiber laser as described in any embodiment of the present invention.

[0077] Among them, the laser processing device can achieve the effects that the fiber laser as described in any embodiment of the present invention can achieve.

[0078] Taking the guiding light as red light as an example, with a wavelength of about 633 nm, by setting the reflection module 104, the reflection module 104 includes a processing light reflection module 1041 and a pump light reflection module 115. The processing light reflection module 1041 cannot pass through except for the processing light wavelength used by the fiber laser, and the light of other wavelengths is hardly affected by the fiber Bragg grating (reflection module 104). In this way, the damage threshold of the red light source of the indicating light is significantly improved, and its output power is almost not affected geometrically. Furthermore, the damage of the returned signal light of the processing to the red light source is avoided, the output power of the red light source of the indicating light is ensured, the probability of damage to the red light of the indicating light is reduced, thereby extending the life of the fiber laser and saving costs.

[0079] The technical solution of the embodiment of the present invention includes a laser module for outputting a laser beam, a guiding light module for outputting a guiding light beam, a wavelength division multiplexer for connecting the laser module and the guiding light module, and a reflection module located between the guiding light module and the wavelength division multiplexer. The wavelength division multiplexer is used to converge the laser beam and the guiding light beam, and the guiding light beam is used to guide the laser beam to process the workpiece to be processed. The reflection module is at least used to reflect the return light beam formed when the laser beam processes the workpiece to be processed. Furthermore, the reflection module provided in the present application can reflect the return light to avoid the return light generated when engraving high-reflectivity materials from entering the inside of the laser through the laser output port and damaging the internal red light source. That is, the reflection module can weaken the influence of the return light on the guiding light module to improve the performance of the guiding light module.

[0080] It should be understood that various forms of the processes shown above can be used, steps can be reordered, added or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and no limitations are imposed herein.

[0081] The above specific embodiments do not limit the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A fiber laser, characterized in that, Comprising: A laser module for outputting a laser beam; A guiding light module for outputting a guiding light beam; A wavelength division multiplexer for connecting the laser module and the guiding light module and for combining the laser beam and the guiding light beam; A reflection module disposed between the guiding light module and the wavelength division multiplexer, the reflection module at least being used for reflecting a return light beam formed when the laser beam processes a workpiece to be processed.

2. The fiber laser according to claim 1, characterized in that, The reflection module includes a processing light reflection module, the period of the processing light reflection module being determined by the wavelength of the return light beam and the effective refractive index of the processing light reflection module, and the processing light reflection module is further used to ensure that the difference between the output power of the guiding light module and the operating power of the guiding light beam is within a preset range, wherein the processing light reflection module is a fiber Bragg grating.

3. The fiber laser according to claim 1, characterized in that, The laser module includes a resonant cavity and an amplification stage; The wavelength division multiplexer is located inside the resonant cavity or between the resonant cavity and the amplification stage.

4. The fiber laser according to claim 3, characterized in that, When the output power of the resonant cavity is greater than or equal to the damage threshold of the wavelength division multiplexer and the power inside the resonant cavity is less than the damage threshold of the wavelength division multiplexer, the wavelength division multiplexer is located inside the resonant cavity; When the output power of the resonant cavity is less than the damage threshold of the wavelength division multiplexer and the power inside the resonant cavity is greater than the damage threshold of the wavelength division multiplexer, the wavelength division multiplexer is located between the resonant cavity and the amplification stage of the laser module.

5. The fiber laser according to claim 1, characterized in that, The laser module further includes a first pump unit, a first gain fiber and a resonant cavity, the resonant cavity including a first fiber Bragg grating and a second fiber Bragg grating that form opposite reflections, wherein, The output end of the first pump unit is connected to the resonant cavity through an optical fiber combiner, and the first gain fiber is disposed inside the resonant cavity; When the wavelength division multiplexer is located inside the resonant cavity, the first end of the wavelength division multiplexer is connected to the first fiber Bragg grating, the second end is connected to the first gain fiber, and the third end is connected to the input end of the return light beam of the reflection module; When the wavelength division multiplexer is located between the resonant cavity and the amplification stage of the laser module, the first end of the wavelength division multiplexer is connected to the output end of the resonant cavity, the second end is connected to the amplification stage, and the third end is connected to the input end of the return light beam of the reflection module.

6. The fiber laser according to claim 5, characterized in that, The resonant cavity further includes a Q-switch, and the Q-switch is located between the first fiber Bragg grating and the first gain fiber.

7. The fiber laser according to claim 1, characterized in that, The amplification stage of the laser module includes a second pump unit, a second optical fiber combiner and a second gain fiber; One side of the second optical fiber combiner is used for connecting the second pump unit and the output end of the resonant cavity of the laser module, and the other side is used for connecting the second gain fiber, and the other end of the second gain fiber is used for outputting the laser beam and the guiding light beam.

8. The fiber laser according to claim 1, characterized in that, The reflection module further includes a pump light reflection module, and the pump light reflection module is disposed between the processing light reflection module and the guiding light module or between the processing light reflection module and the wavelength division multiplexer, wherein the pump light reflection module is a fiber Bragg grating.

9. The fiber laser according to claim 1, characterized in that, The guiding light module is one of a red light source, a green light source, a purple light source or a blue light source.

10. A laser processing device, comprising the fiber laser according to any one of claims 1-9.

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