Laser device capable of processing highly reflective materials and reflected light processing method

Abstract

The present invention discloses a laser device capable of processing highly reflective materials and a reflected light processing method, belonging to the technical field of reflected light processing. The present invention is designed to solve the problem of reflected light burning the front-end optical path components of the laser during cutting or welding. The present invention comprises: an indicator light laser, a reverse mode stripper, a pump source, a beam combiner, a high-reflective grating, a gain optical fiber, a low-reflective grating, a reverse beam combiner, a mode stripper, a reflected light attenuator and an optical fiber output device. The present invention transmits a large amount of core light into the cladding, and strips the cladding light by stripping technology, ultimately achieving the purpose of protecting the optical path.

Description

Technical Field

[0001] The invention relates to the technical field of reflected light processing, and in particular to a laser device capable of processing highly reflective materials and a reflected light processing method. Background Art

[0002] Laser devices, such as fiber lasers, are used to cut or weld highly reflective materials in practical applications. However, the current anti-reflection light performance of fiber lasers is far from meeting the requirements of actual use, resulting in the burning of fiber laser devices due to excessive reflected light during application.

[0003] Reflected light mainly exists in the perforation stage of cutting and the entire welding process. When the laser output head is perpendicular to the processing plane of the high-reflective material, a large part of the reflected light is coupled into the core of the optical fiber and transmitted in the reverse direction along the laser optical path. When the reflected light is too large, it will cause damage to the optical path devices at the front end of the fiber laser, and then cause the fiber laser to fail.

[0004] The problem of reflected light not only limits the practical application of fiber lasers, but also affects the stable operation of fiber lasers and shortens their service life. Summary of the invention

[0005] In view of this, the present invention provides the following technical solutions to solve the problem of reflected light burning the laser front-end optical path components during cutting or welding:

[0006] Provided is a laser device capable of processing high-reflective materials, the laser device comprising an indicator light laser, a reverse mode stripper, a forward pump source, a forward beam combiner, a high-reflective grating, a gain optical fiber, a low-reflective grating, a reverse beam combiner, a forward mode stripper and an optical fiber output device;

[0007] The optical path transmission direction of the laser device is consistent with the transmission direction of the indicator light laser. When the indicator light laser is working, it passes through the reverse mode stripper, the forward pump source, the forward beam combiner, the high-reflection grating, the gain fiber, the low-reflection grating, the reverse beam combiner, the forward mode stripper, and finally outputs through the optical fiber output device.

[0008] Optionally, a reverse pump source is connected to one end of the reverse beam combiner close to the forward stripper.

[0009] Optionally, the laser device further comprises a reflected light attenuator, wherein the reflected light attenuator is located between the reverse mold stripper and the indicator light laser.

[0010] Optionally, the reflected light attenuator includes a reflected light attenuation section, which is composed of an input section optical fiber, a middle section optical fiber and an output section optical fiber, wherein the reflected light transmission direction is: the initial end of the input section optical fiber-the terminal end of the input section optical fiber-the middle section optical fiber-the initial end of the output section optical fiber-the terminal end of the output section optical fiber.

[0011] Optionally, when the reflected light attenuator is working, the core reflected light is input through the input section optical fiber, and when passing through the tapered region between the input section optical fiber and the middle section optical fiber, the mode field area of ​​the core reflected light gradually increases from the input section optical fiber to the core mode field area of ​​the middle section optical fiber, and when passing through the tapered region between the middle section optical fiber and the output section optical fiber, the middle section optical fiber gradually decreases to the core mode field area of ​​the output section optical fiber.

[0012] Optionally, the forward combiner signal optical fiber has a core of 20 μm and a cladding of 400 μm, that is, the forward combiner signal optical fiber is a 20 / 400 double-clad optical fiber, the coating is 530 μm, and the core NA is 0.07;

[0013] The input section optical fiber of the reflected light attenuator is a 20 / 400 double-clad optical fiber with a core NA of 0.07;

[0014] The middle section optical fiber is a 50 / 400 double-clad optical fiber with a core NA of 0.12;

[0015] The output section optical fiber is a 20 / 400 double-clad optical fiber with a core NA of 0.07. After the core reflected light passes through the reflected light attenuator, the attenuation coefficient can reach 4dB according to testing.

[0016] Optionally, the signal fiber of the combiner is a 20 / 400 double-clad fiber with a core NA of 0.07;

[0017] The input section optical fiber of the reflected light attenuator is a 20 / 400 double-clad optical fiber with a core NA of 0.07;

[0018] The middle section optical fiber is a 50 / 70 / 360 triple-clad optical fiber with a core NA of 0.22;

[0019] The output fiber is 20 / 400 double-clad fiber with a core NA of 0.07. After the reflected light from the core passes through the reflected light attenuator, the attenuation coefficient is tested to be 8dB.

[0020] Optionally, the signal fiber of the combiner is a 14 / 250 double-clad fiber with a core NA of 0.07;

[0021] The input section optical fiber of the reflected light attenuator is a 14 / 250 double-clad optical fiber with a core NA of 0.07;

[0022] The middle section fiber is a 50 / 70 / 360 triple-clad fiber with a core NA of 0.22;

[0023] The output fiber is 12 / 250 double-clad fiber with a core NA of 0.07. After the reflected light from the core passes through the reflected light attenuator, the attenuation coefficient can reach 10dB after testing.

[0024] Optionally, a photothermal conversion wall is further provided on the outside of the reflected light attenuator, and a cold water pipe is provided on the outer layer of the photothermal conversion wall. After the core reflected light passes through the photothermal conversion wall, the heat energy of the core reflected light is conducted to the inner layer of the photothermal conversion wall, and the heat energy is conducted away through the water via the cold water pipe.

[0025] Optionally, the light-to-heat conversion wall is provided with an optical fiber fixing hole, and the reflected light attenuation section passes through and is fixed in the optical fiber fixing hole.

[0026] A reflected light processing method is also provided, and the processing method can be implemented by any of the above-mentioned laser devices capable of processing high-reflective materials.

[0027] A reflected light processing method includes:

[0028] Step S10, when the laser device is started and no material is processed, the pump source emits pump laser, which is coupled into the single fiber cladding through the forward / reverse beam combiner, and the cladding pump laser is converted into the core fiber laser in the resonant cavity composed of the high / low reflection grating and the gain fiber. After the residual cladding light is stripped by the stripper, the laser is output from the fiber output device, and the laser does not pass through the reflected light attenuator. At this time, the reflected light attenuator does not work;

[0029] Step S20, when the laser device processes the material, a large amount of reflected light is re-coupled back into the laser light path through the principle of optical path reciprocity and transmitted in the reverse direction along the optical path, wherein the reflected light coupled into the cladding is basically stripped away by the stripper, and the core reflected light is partially coupled into the cladding when passing through the combiner and stripped away by the stripper, and the remaining core reflected light can still reach the order of hundreds of watts. At this time, the reflected light attenuator works to couple the core reflected light into the cladding and strip it away, wherein the material includes a high-reflective material, and the actions of processing the material include cutting and welding.

[0030] Wherein, step S20 includes:

[0031] Step S201, the optical fiber output device emits a laser beam to the surface of a high-reflective material, and the reflected light reflected from the surface of the high-reflective material is coupled into the core of the optical fiber to obtain the core reflected light, and the core reflected light is transmitted in the reverse direction along the optical path of the laser device;

[0032] Step S202, when the reflected light attenuator is working, the reflected light from the fiber core passes through the cone areas of the input section optical fiber and the middle section optical fiber in sequence;

[0033] When passing through the tapered area of ​​the middle fiber and the output fiber, since the mode field area of ​​the output fiber core is smaller than the mode field area of ​​the middle fiber core, most of the core reflected light is coupled into the cladding of the tapered area.

[0034] Step S203, performing mode stripping on the cladding of the tapered region and the output section optical fiber by using a reverse mode stripper, wherein the reverse mode stripper is used to strip off most of the core reflected light coupled into the cladding, thereby achieving the purpose of attenuating the reflected light.

[0035] The beneficial effects of the present invention are as follows: after the present invention adds a reflected light attenuator, according to the light in the large mode field area optical fiber is transmitted to the small mode field area optical fiber, a large amount of core light will be transmitted to the cladding, and the cladding light will be stripped by stripping technology, and finally the purpose of protecting the optical path is achieved. The manufacturing process of the present invention is simple, the cost is low, it is convenient to match with conventional lasers, and it can greatly improve the anti-reflection light capability of conventional lasers. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the overall structure of the invention;

[0037] Figure 2 The invention is a schematic diagram of the structure of the reflected light attenuator;

[0038] Figure 3 A schematic diagram of the process of inventing a reflected light processing method;

[0039] Figure 4 This is a schematic diagram of the packaging of the invented reflected light attenuator. DETAILED DESCRIPTION

[0040] Embodiments of the invention are described in detail below, and examples of the embodiments 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 invention, and should not be construed as limitations on the invention. In the description of the invention, it should be understood that the orientation or positional relationship indicated by the terms "inside", "upper", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the invention.

[0041] In addition, in the description of the invention, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0042] The invention will be further described below in conjunction with the accompanying drawings:

[0043] Reference Figure 1 In the first embodiment of the invention, a laser device capable of processing high-reflective materials is provided, the laser device comprising an indicator light laser 1, a reverse mode stripper 2, a forward pump source 3, a forward beam combiner 4, a high-reflective grating 5, a gain fiber 6, a low-reflective grating 7, a reverse beam combiner 8, a forward mode stripper 9 and a fiber output device 10;

[0044] The optical path transmission direction of the laser device is consistent with the transmission direction of the indicator light laser 1. When the indicator light laser 1 is working, it passes through the reverse mode stripper 2, the forward pump source 3, the forward beam combiner 4, the high reflection grating 5, the gain fiber 6, the low reflection grating 7, the reverse beam combiner 8, the forward mode stripper 9, and finally outputs through the optical fiber output device 10;

[0045] One end of the reverse beam combiner 8 close to the forward stripper 9 is connected to a reverse pump source 15;

[0046] The laser device further comprises a reflected light attenuator 11, which is located between the reverse stripper 2 and the indicator light laser 1;

[0047] The reflected light attenuator 11 includes a reflected light attenuation section, which is composed of an input section optical fiber, a middle section optical fiber and an output section optical fiber, wherein the reflected light transmission direction is: the initial end of the input section optical fiber - the terminal of the input section optical fiber - the middle section optical fiber - the initial end of the output section optical fiber - the terminal of the output section optical fiber;

[0048] When the reflected light attenuator 11 is working, the core reflected light is input through the input section optical fiber. When passing through the cone area of ​​the input section optical fiber and the middle section optical fiber, the mode field area of ​​the core reflected light gradually increases from the input section optical fiber to the core mode field area of ​​the middle section optical fiber. When passing through the cone area of ​​the middle section optical fiber and the output section optical fiber, the middle section optical fiber gradually decreases to the core mode field area of ​​the output section optical fiber. The core mode field area of ​​the initial section of the input section optical fiber is the same as the core mode field area of ​​the signal end of the forward combiner 4, which is used to match the signal end optical fiber of the forward combiner 4. The core mode field area of ​​the middle section optical fiber is larger. The core mode field area at the beginning of the input section optical fiber is the core mode field area of ​​the fiber, and the two ends of the middle section optical fiber are matched with the core diameter of the input section optical fiber and the output section optical fiber by taper pulling. The core mode field area of ​​the terminal of the output section optical fiber is smaller than the core mode field area of ​​the middle section optical fiber. Since the core mode field area of ​​the output section optical fiber is smaller than the core mode field area of ​​the middle section optical fiber, most of the core reflected light is coupled into the cladding of the cone area. The stripping treatment is performed on the cladding of the cone area and the output section optical fiber to realize stripping of most of the core reflected light coupled into the cladding, thereby achieving the purpose of attenuating the reflected light.

[0049] The signal fiber of the forward combiner 4 has a core of 20 μm and a cladding of 400 μm, that is, the signal fiber of the forward combiner 4 is a 20 / 400 double-clad fiber, the coating is 530 μm, and the core NA is 0.07;

[0050] The input fiber of the reflection light attenuator 11 is a 20 / 400 double-clad fiber with a core NA of 0.07; the middle fiber is a 50 / 400 double-clad fiber with a core NA of 0.12; the output fiber is a 20 / 400 double-clad fiber with a core NA of 0.07. After the core reflected light passes through the reflection light attenuator, the attenuation coefficient can reach 4dB after testing. The fiber models here include but are not limited to this type, and the above are only optional.

[0051] Reference Figure 1 In the second embodiment of the invention, the combiner signal fiber is a 20 / 400 double-clad fiber with a core NA of 0.07;

[0052] The input fiber of the reflection light attenuator is 20 / 400 double-clad fiber with a core NA of 0.07;

[0053] The middle section fiber is a 50 / 70 / 360 triple-clad fiber with a core NA of 0.22;

[0054] The output fiber is 20 / 400 double-clad fiber, the core NA is 0.07, and the core reflected light passes through the reflected light attenuator, and the attenuation coefficient can reach 8dB after testing. The fiber models here include but are not limited to this type, and the above are only optional.

[0055] Reference Figure 1In the third embodiment of the invention, the combiner signal fiber is a 14 / 250 double-clad fiber with a core NA of 0.07;

[0056] The input fiber of the reflected light attenuator is 14 / 250 double-clad fiber with a core NA of 0.07;

[0057] The middle section fiber is a 50 / 70 / 360 triple-clad fiber with a core NA of 0.22;

[0058] The output fiber is 12 / 250 double-clad fiber, the core NA is 0.07, and the core reflected light passes through the reflected light attenuator, and the attenuation coefficient can reach 10dB after testing. The fiber models here include but are not limited to this type, and the above are only optional.

[0059] Reference Figure 1 , 2 And 4, in the fourth embodiment of the invention, a light-to-heat conversion wall 12 is further provided on the outside of the reflected light attenuator 11, and a cold water pipe 13 is provided on the outer layer of the light-to-heat conversion wall 12. After the core reflected light passes through the light-to-heat conversion wall 12, the heat energy of the core reflected light is conducted to the inner layer of the light-to-heat conversion wall 12, and the heat energy is conducted away through the water via the cold water pipe 13.

[0060] The light-to-heat conversion wall 12 is provided with an optical fiber fixing hole 14, and the reflected light attenuation section passes through and is fixed in the optical fiber fixing hole 14. The light-to-heat conversion wall 12 is provided with a heat sink fixing hole 16, and the light-to-heat conversion wall 12 is provided with a cold water pipe 13.

[0061] An embodiment of a reflected light processing method is also provided. The processing method can be implemented by any of the above-mentioned laser devices capable of processing high-reflective materials.

[0062] Specifically, the reflected light processing method may include:

[0063] Step S10, when the laser device is started and no material is processed, the pump source emits pump laser, which is coupled into the single fiber cladding through the forward / reverse beam combiner, and the cladding pump laser is converted into the core fiber laser in the resonant cavity composed of the high / low reflection grating and the gain fiber. After the residual cladding light is stripped by the stripper, the laser is output from the fiber output device, and the laser does not pass through the reflected light attenuator, and the reflected light attenuator does not work at this time;

[0064] Step S20, when the laser device processes the material, a large amount of reflected light is re-coupled back into the laser light path through the principle of optical path reciprocity, and transmitted in the reverse direction along the optical path, wherein the reflected light coupled into the cladding is basically stripped away by the stripper, and the core reflected light is partially coupled into the cladding when passing through the combiner and stripped away by the stripper, and the remaining core reflected light can still reach the order of hundreds of watts, at which time the reflected light attenuator works to couple the core reflected light into the cladding and strip it away, wherein the material includes a highly reflective material, and the actions of processing the material include cutting and welding.

[0065] Reference Figure 3 , in another embodiment comprising:

[0066] Step S201, the optical fiber output device emits a laser beam to the surface of a high-reflective material, and the reflected light from the surface of the high-reflective material is coupled into the core of the optical fiber to obtain the core reflected light, and the core reflected light is transmitted in the reverse direction along the optical path of the laser device;

[0067] Step S202, when the reflected light attenuator is working, the reflected light from the fiber core passes through the cone areas of the input section optical fiber and the middle section optical fiber in sequence;

[0068] When passing through the tapered area of ​​the middle fiber and the output fiber, since the mode field area of ​​the output fiber core is smaller than the mode field area of ​​the middle fiber core, most of the core reflected light is coupled into the cladding of the tapered area.

[0069] Step S203, performing mode stripping on the cladding of the tapered region and the output section optical fiber by using a reverse mode stripper, wherein the reverse mode stripper is used to strip off most of the core reflected light coupled into the cladding, thereby achieving the purpose of attenuating the reflected light.

[0070] The technical principles of the invention are described above in conjunction with specific embodiments. These descriptions are only for explaining the principles of the invention and cannot be interpreted in any way as limiting the scope of protection of the invention. Based on the explanations here, those skilled in the art can think of other specific implementations of the invention without creative work, and these methods will fall within the scope of protection of the invention.

Claims

1. A laser device capable of processing highly reflective materials, characterized in that: The laser device is composed of an indicator light laser (1), a reverse mode stripper (2), a forward pump source (3), a forward beam combiner (4), a high-reflection grating (5), a gain optical fiber (6), a low-reflection grating (7), a reverse beam combiner (8), a forward mode stripper (9) and an optical fiber output device (10); The optical path transmission direction of the laser device is consistent with the transmission direction of the indicator light laser (1). When the indicator light laser (1) is in operation, the indicator light is transmitted through the reverse mode stripper (2), the forward pump source (3), the forward beam combiner (4), the high-reflection grating (5), the gain fiber (6), the low-reflection grating (7), the reverse beam combiner (8), the forward mode stripper (9), and finally output through the optical fiber output device (10); The laser device further comprises a reflected light attenuator (11), wherein the reflected light attenuator (11) is located between the reverse stripper (2) and the indicator light laser (1); The reflected light attenuator (11) comprises a reflected light attenuation section, which is composed of an input section optical fiber, a middle section optical fiber and an output section optical fiber, wherein the reflected light transmission direction is: the initial end of the input section optical fiber-the terminal of the input section optical fiber-the middle section optical fiber-the initial end of the output section optical fiber-the terminal of the output section optical fiber; the core mode field area of ​​the initial section of the input section optical fiber is the same as the core mode field area of ​​the signal end of the forward combiner, and is used to match the optical fiber at the signal end of the forward combiner; When the reflected light attenuator (11) is working, the core reflected light is input through the input section optical fiber, and when passing through the tapered area between the input section optical fiber and the middle section optical fiber, the mode field area of ​​the core reflected light gradually increases from the input section optical fiber to the core mode field area of ​​the middle section optical fiber, and when passing through the tapered area between the middle section optical fiber and the output section optical fiber, the middle section optical fiber gradually decreases to the core mode field area of ​​the output section optical fiber; A light-to-heat conversion wall (12) is also provided outside the reflected light attenuator (11); The light-to-heat conversion wall (12) is provided with an optical fiber fixing hole (14), and the reflected light attenuation section passes through and is fixed in the optical fiber fixing hole (14).

2. A laser device capable of processing high-reflective materials as claimed in claim 1, characterized in that: One end of the reverse beam combiner (8) close to the forward stripper (9) is connected to a reverse pump source (15).

3. The laser device capable of processing high-reflective materials as claimed in claim 1, characterized in that: The signal optical fiber of the forward beam combiner (4) has a core of 20 μm and a cladding of 400 μm, that is, the signal optical fiber of the forward beam combiner (4) is a 20 / 400 double-clad optical fiber, the coating is 530 μm, and the core NA is 0.07; The input section optical fiber of the reflected light attenuator (11) is a 20 / 400 double-clad optical fiber, and the core NA is 0.07; The middle section optical fiber is a 50 / 400 double-clad optical fiber with a core NA of 0.12; The output section optical fiber is a 20 / 400 double-clad optical fiber, and the core NA is 0.

07.

4. The laser device capable of processing high-reflective materials as claimed in claim 1, characterized in that: The signal fiber of the forward combiner is 20 / 400 double-clad fiber with a core NA of 0.07; The input section optical fiber of the reflected light attenuator (11) is a 20 / 400 double-clad optical fiber, and the core NA is 0.07; The middle section optical fiber is a 50 / 70 / 360 triple-clad optical fiber with a core NA of 0.22; The output fiber is 20 / 400 double-clad fiber with a core NA of 0.

07.

5. The laser device capable of processing high-reflective materials as claimed in claim 1, characterized in that: The signal fiber of the forward combiner is 14 / 250 double-clad fiber with a core NA of 0.07; The input section optical fiber of the reflected light attenuator (11) is a 14 / 250 double-clad optical fiber, and the core NA is 0.07; The middle section fiber is a 50 / 70 / 360 triple-clad fiber with a core NA of 0.22; The output fiber is 12 / 250 double-clad fiber with a core NA of 0.

07.

6. The laser device capable of processing high-reflective materials according to any one of claims 3 to 5, characterized in that: The outer layer of the light-to-heat conversion wall (12) is provided with a cold water pipe (13); after the light reflected by the core passes through the light-to-heat conversion wall (12), the heat energy of the light reflected by the core is conducted to the inner layer of the light-to-heat conversion wall (12), and the heat energy is conducted away through water via the cold water pipe (13).

7. A method for processing reflected light, characterized in that: The processing method can be realized by any one of the laser devices capable of processing high-reflective materials in claims 1 to 6.

8. The reflected light processing method according to claim 7, characterized in that: include: Step S10, when the laser device is started and no material is processed, the pump source emits pump laser, which is coupled into the single fiber cladding through the forward / reverse beam combiner, and in the resonant cavity composed of the high / low reflection grating and the gain fiber, the cladding pump laser is converted into the core fiber laser, and after the residual cladding light is stripped by the stripper, the laser is output from the fiber output device (10); Step S20, when the laser device processes the material, a large amount of reflected light is re-coupled back into the optical path of the laser device through the principle of optical path reciprocity, and is transmitted in the reverse direction along the optical path, wherein the reflected light coupled into the cladding is basically stripped away by the stripper, and the core reflected light is partially coupled into the cladding when passing through the beam combiner and is stripped away by the stripper, and the remaining core reflected light can still reach the order of hundreds of watts. At this time, the reflected light attenuator (11) works to couple the core reflected light into the cladding and strip it away, wherein the material includes a high-reflective material, and the action of processing the material includes cutting and welding.

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