CN115106643A

CN115106643A - Laser device capable of processing high-reflection material and reflected light processing method

Info

Publication number: CN115106643A
Application number: CN202110298460.7A
Authority: CN
Inventors: 刘梦寒; 龚凯; 卢国杰; 韩金龙; 牛增强
Original assignee: United Winners Laser Co Ltd
Current assignee: United Winners Laser Co Ltd
Priority date: 2021-03-19
Filing date: 2021-03-19
Publication date: 2022-09-27

Abstract

The invention discloses a laser device capable of processing high-reflectivity materials and a reflected light processing method, belongs to the technical field of reflected light processing, and is designed for solving the problem that reflected light burns out a front-end light path device of a laser during cutting or welding. The invention comprises the following steps: the device comprises an indicating light laser, a reverse mode stripper, a pumping source, a beam combiner, a high-reflection grating, a gain optical fiber, a low-reflection grating, a reverse beam combiner, a mode stripper, a reflection optical attenuator and an optical fiber output device. The invention can transmit a large amount of fiber core light into the cladding, and strip the cladding light by a stripping technology, thereby finally achieving the purpose of protecting the light path.

Description

Laser device capable of processing high-reflection material and reflected light processing method

Technical Field

The invention relates to the technical field of reflected light processing, in particular to a laser device capable of processing high-reflectivity materials and a reflected light processing method.

Background

A laser device, such as a fiber laser, can cut or weld high-reflection materials in practical application, but the anti-reflection performance of the existing fiber laser can not meet the practical use requirement far, so that the fiber laser burns devices due to overlarge reflected light in application.

The reflected light mainly exists in the perforation stage of cutting and the whole welding process, when the laser output head is vertical to the processing plane of the high-reflection material, a large part of the reflected light is coupled into the fiber core of the optical fiber and is transmitted along the optical path of the laser in the reverse direction, and when the reflected light is too large, the device of the optical path at the front end of the optical fiber laser can be damaged, so that the optical fiber laser fails.

The problem of reflected light not only limits the practical application of the fiber laser, but also influences the stable operation of the fiber laser and shortens the service life of the fiber laser.

Disclosure of Invention

In view of this, the present invention provides the following technical solutions for solving the problem that the reflected light burns the optical path device at the front end of the laser during cutting or welding:

the laser device capable of processing the high-reflectivity material is provided and consists of an indicating light laser, a reverse mode stripper, a forward pumping source, a forward beam combiner, a high-reflectivity grating, a gain fiber, a low-reflectivity grating, a reverse beam combiner, a forward mode stripper and a fiber output device;

the transmission direction of the optical path of the laser device is consistent with that of the indicating light laser, and after the indicating light laser works, the optical path is output through the optical fiber output device finally via the reverse mode stripper, the forward pumping source, the forward beam combiner, the high-reverse grating, the gain optical fiber, the low-reverse grating, the reverse beam combiner and the forward mode stripper.

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

Optionally, the laser device further includes a reflective optical attenuator, and the reflective optical attenuator is located between the reverse mode stripper and the indicating light laser.

Optionally, the reflected light attenuator includes a reflected light attenuation section, where the reflected light attenuation section is composed of an input section optical fiber, a middle section optical fiber, and an output section optical fiber, where a 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 and the terminal of the output section optical fiber.

Optionally, when the reflective optical attenuator operates, the fiber core reflected light is input through the input section optical fiber, when the reflected light passes through the tapered regions of the input section optical fiber and the middle section optical fiber, the mode field area of the fiber core reflected light is gradually increased from the input section optical fiber to the fiber core mode field area of the middle section optical fiber, and when the reflected light passes through the tapered regions of the middle section optical fiber and the output section optical fiber, the middle section optical fiber is gradually decreased to the fiber core mode field area of the output section optical fiber.

Optionally, the forward beam combiner signal fiber is 20 μm in core and 400 μm in cladding, that is, the forward beam combiner signal fiber is 20/400 double-clad fiber core, the coating layer is 530 μm, and the NA is 0.07;

the input section of the reflecting optical attenuator is 20/400 double-clad optical fiber, and the fiber core NA is 0.07;

the middle section of the optical fiber is 50/400 double-clad optical fiber, and the NA of the fiber core is 0.12;

the output section optical fiber is 20/400 double-clad optical fiber, the fiber core NA is 0.07, and the attenuation coefficient can reach 4dB through testing after the reflected light of the fiber core passes through the reflecting optical attenuator.

Optionally, the signal fiber of the beam combiner is 20/400 double-clad fiber, and the core NA is 0.07;

the middle section of the optical fiber is 50/70/360 triple-clad optical fiber, and the NA of the fiber core is 0.22;

the output section optical fiber is 20/400 double-clad optical fiber, the fiber core NA is 0.07, and the attenuation coefficient can reach 8dB through testing after the reflected light of the fiber core passes through the reflected light attenuator.

Optionally, the signal fiber of the beam combiner is 14/250 double-clad fiber, and the core NA is 0.07;

the input section of the reflecting optical attenuator is 14/250 double-clad optical fiber, and the fiber core NA is 0.07;

the middle section optical fiber is 50/70/360 triple-clad optical fiber, and the core NA is 0.22;

the output section optical fiber is 12/250 double-clad optical fiber, the fiber core NA is 0.07, and the attenuation coefficient can reach 10dB through testing after the reflected light of the fiber core passes through the reflected light attenuator.

Optionally, the reflected light attenuator outside still is equipped with the light and heat conversion wall, the skin of light and heat conversion wall is equipped with the cold water pipeline, and the fibre core reverberation passes through behind the light and heat conversion wall, the heat energy conduction of fibre core reverberation extremely on the light and heat conversion wall inlayer, via the cold water pipeline is gone out heat energy conduction through water.

Optionally, the photothermal conversion wall is provided with an optical fiber fixing hole, and the reflected light attenuation section penetrates through and is clamped in the optical fiber fixing hole.

There is also provided a reflected light processing method which can be realized by any of the above-described laser devices which can process a high-reflective material.

A reflected light processing method includes:

step S10, when the laser device is started and any material is not processed, the pump source emits pump laser, the pump laser is coupled into a single optical fiber cladding through a forward/backward beam combiner, the cladding pump laser is converted into fiber core fiber laser in a resonant cavity formed by a high/low-reflection grating and a gain fiber, the laser is output from a fiber output device after the residual cladding light is stripped through a stripper, the laser does not pass through a reflective optical attenuator, and the reflective optical attenuator does not work at this time;

step S20, when the laser device processes material, a large amount of reflected light is coupled back to the laser path again through the principle of optical path reciprocal and transmitted along the optical path reversely, wherein the reflected light coupled into the cladding is stripped completely by the stripper, part of the fiber core reflected light is coupled into the cladding when passing through the beam combiner and stripped by the stripper, the residual fiber core reflected light still reaches hundreds of watts, at this time, the reflected light attenuator works to couple the fiber core reflected light into the cladding and strip, wherein the material comprises high-reflectivity material, and the action of processing the material comprises cutting and welding.

Wherein, step S20 includes:

step S201, a laser beam is emitted to the surface of a high-reflection material by an optical fiber output device, reflected light reflected from the surface of the high-reflection material is coupled into a fiber core of an optical fiber to obtain fiber core reflected light, and the fiber core reflected light is transmitted along the optical path of a laser device in a reverse direction;

step S202, when the reflection optical attenuator works, the fiber core reflected light sequentially passes through the cone regions of the input section optical fiber and the middle section optical fiber;

when the fiber passes through the tapered regions of the middle section fiber and the output section fiber, most of fiber core reflected light is coupled into a cladding of the tapered region because the mode field area of the fiber core of the output section fiber is smaller than that of the fiber core of the middle section fiber;

step S203, a reverse mode stripper is used for stripping most of the core reflected light coupled into the cladding so as to achieve the purpose of attenuating the reflected light.

The beneficial effects of the invention are as follows: after the reflection light attenuator is added, a large amount of fiber core light is transmitted into the cladding according to the transmission of the light in the large mode area optical fiber to the small mode area optical fiber, and the cladding light is stripped through a stripping technology, so that the aim of protecting the light path is fulfilled finally. The invention has simple manufacturing process and low cost, is convenient to match with the conventional laser, and can greatly improve the anti-reflection capability of the conventional laser.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic diagram of the structure of the reflective optical attenuator of the present invention;

FIG. 3 is a flow chart of a reflected light processing method according to the present invention;

FIG. 4 is a diagram of the package of the reflective optical attenuator of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention. In the description of the invention, it is to be understood that the terms "in", "on", and the like, indicate orientations or positional relationships based on those shown in the drawings, are merely for convenience in describing the invention and simplifying the description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the invention.

Furthermore, in the description of the invention, unless explicitly stated or limited otherwise, the term "connected" is to be understood broadly, e.g. as a fixed connection, a detachable connection, or an integral part; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The invention is further described below with reference to the accompanying drawings:

referring to fig. 1, in a first embodiment of the invention, a laser device capable of processing high-reflectivity materials is provided, and the laser device is composed of an indicating light laser 1, a reverse mode stripper 2, a forward pump source 3, a forward beam combiner 4, a high-reflectivity grating 5, a gain fiber 6, a low-reflectivity grating 7, a reverse beam combiner 8, a forward mode stripper 9 and a fiber output device 10;

the transmission direction of the light path of the laser device is consistent with that of the indicating light laser 2, and after the indicating light laser 1 works, the light is output through an optical fiber output device 10 finally through a reverse mode stripper 2, a forward pumping source 3, a forward beam combiner 4, a high-reverse grating 5, a gain optical fiber 6, a low-reflection grating 7, a reverse beam combiner 8 and a forward mode stripper 9;

one end of the reverse beam combiner 8 close to the forward stripping device 9 is connected with a reverse pump source 15;

the laser device also comprises a reflection optical attenuator 11, wherein the reflection optical attenuator 11 is positioned between the reverse mode stripper 2 and the indicating light laser 1;

the reflected light attenuator 11 includes a reflected light attenuation section, and the reflected light attenuation section 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 method comprises the following steps of (1) initial end of an input section optical fiber-terminal end of the input section optical fiber-middle section optical fiber-initial end of an output section optical fiber-terminal end of the output section optical fiber;

when the reflection optical attenuator 11 works, the fiber core reflected light is input through the input section optical fiber, when the reflected light passes through the cone regions of the input section optical fiber and the middle section optical fiber, the mode field area of the fiber core reflected light is gradually increased from the input section optical fiber to the fiber core mode field area of the middle section optical fiber, when the reflected light passes through the cone regions of the middle section optical fiber and the output section optical fiber, the middle section optical fiber is gradually decreased to the fiber core mode field area of the output section optical fiber, the fiber core mode field area of the initial section of the input section optical fiber is the same as the fiber core mode field area of the signal end of the forward beam combiner 4 and is used for matching the signal end optical fiber of the forward beam combiner 4, the fiber core mode field area of the middle section optical fiber is larger than the fiber core mode field area of the initial end of the input section optical fiber, the fiber ends of the middle section optical fiber are matched with the fiber core diameters of the input section optical fiber and the output section optical fiber through the tapered fiber, the fiber core mode field area of the output section optical fiber is smaller than the fiber area of the fiber of the middle section optical fiber, therefore, most of the reflected light of the fiber core is coupled into the cladding of the cone area, and the cladding of the optical fiber at the cone area and the output section is subjected to mode stripping treatment, so that most of the reflected light of the fiber core coupled into the cladding is stripped, and the aim of attenuating the reflected light is fulfilled;

the signal fiber of the forward combiner 4 is 20 μm of fiber core and 400 μm of cladding, namely the signal fiber of the forward combiner 4 is 20/400 double-clad fiber core, the coating layer is 530 μm, and the NA is 0.07;

the input section of the optical fiber of the reflected light attenuator 11 is 20/400 double-clad optical fiber, and the core NA is 0.07; the middle section optical fiber is 50/400 double-clad optical fiber, and the core NA is 0.12; the output section of the optical fiber is 20/400 double-clad optical fiber, and the core NA is 0.07. The attenuation coefficient can reach 4dB through testing after the reflected light of the fiber core passes through the reflected light attenuator. The fiber type here is not limited to the present type, but the above is only an option.

Referring to fig. 1, in a second embodiment of the invention, the combiner signal fiber is an 20/400 double-clad fiber, and the core NA is 0.07;

the output section optical fiber is 20/400 double-clad optical fiber, the fiber core NA is 0.07, and the attenuation coefficient can reach 8dB through testing after the reflected light of the fiber core passes through the reflected light attenuator. The fiber type here is not limited to the present type, but the above is only an option.

Referring to fig. 1, in a third embodiment of the invention, the combiner signal fiber is an 14/250 double-clad fiber, and the core NA is 0.07;

the input section optical fiber of the reflecting optical attenuator is 14/250 double-clad optical fiber, and the NA of a fiber core is 0.07;

the output section optical fiber is 12/250 double-clad optical fiber, the fiber core NA is 0.07, and the attenuation coefficient can reach 10dB through testing after the reflected light of the fiber core passes through the reflected light attenuator. The fiber type here is not limited to the present type, but the above is only an option.

Referring to fig. 1, 2 and 4, in the fourth embodiment of the invention, a photo-thermal conversion wall 12 is further disposed outside the reflective light attenuator 11, a cold water duct 13 is disposed on an outer layer of the photo-thermal conversion wall 12, and after the core reflected light passes through the photo-thermal conversion wall 12, heat energy of the core reflected light is conducted to an inner layer of the photo-thermal conversion wall 12, and the heat energy is conducted out through water via the cold water duct 13.

The photothermal conversion wall 12 is provided with an optical fiber fixing hole 14, and the reflected light attenuation section penetrates through and is clamped in the optical fiber fixing hole 14. The photothermal conversion wall 12 is provided with a heat sink fixing hole 16, and the photothermal conversion wall 12 is provided with a communicated cold water pipeline 13.

There is also provided an embodiment of a reflected light processing method, which can be realized by any of the above-described laser apparatuses capable of processing a high-reflective material.

Specifically, the reflected light processing method may include:

step S10, when the laser device is started and any material is not processed, the pump source emits pump laser, the pump laser is coupled into a single optical fiber cladding through a forward/backward beam combiner, the cladding pump laser is converted into fiber core fiber laser in a resonant cavity formed by a high/low-reflection grating and a gain fiber, after the residual cladding light is stripped through a stripper, the laser is output from a fiber follower, the laser does not pass through a reflective optical attenuator, and the reflective optical attenuator does not work at this time;

step S20, when the laser device processes material, a large amount of reflected light is coupled back to the laser path again by the principle of optical path reciprocal and transmitted along the optical path reversely, wherein the reflected light coupled into the cladding is stripped completely by the stripper, part of the core reflected light is coupled into the cladding when passing through the beam combiner and stripped by the stripper, the residual core reflected light still reaches hundreds of watts, at this time, the reflected light attenuator works to couple the core reflected light into the cladding and strip, wherein the material comprises high-reflectivity material, and the action of processing the material comprises cutting and welding.

Referring to fig. 3, in another embodiment includes:

step S201, the optical fiber output device emits laser beams to the surface of the high-reflection material, reflected light reflected from the surface of the high-reflection material is coupled into a fiber core of the optical fiber to obtain fiber core reflected light, and the fiber core reflected light is transmitted along the optical path of the laser device in the reverse direction;

The technical principle of the invention is described above with reference to specific embodiments. The description is made for the purpose of illustrating the principles of the invention and should not be construed in any way as limiting the scope of the invention. Based on the explanations herein, those skilled in the art will be able to conceive other embodiments of the invention without inventive step, which shall fall within the scope of the invention.

Claims

1. The laser device capable of processing the high-reflection material is characterized by comprising an indicating light laser (1), a reverse mode stripper (2), a forward pumping 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 light path transmission direction of the laser device is consistent with the transmission direction of the indicating light laser (2), and when the indicating light laser (1) works, the light path transmission direction is finally output through the optical fiber output device (10) via the reverse mode stripper (2), the forward pumping source (3), the forward beam combiner (4), the high-reverse grating (5), the gain optical fiber (6), the low-reverse grating (7), the reverse beam combiner (8) and the forward mode stripper (9).

2. The laser device for processing high-reflectivity materials as claimed in claim 1, wherein the backward beam combiner (8) is connected with a backward pump source (15) at one end close to the forward stripper (9).

3. The laser device capable of processing high-reflectivity materials according to claim 2, further comprising a reflective optical attenuator (11), wherein the reflective optical attenuator (11) is located between the reverse mode stripper (2) and the indicator laser (1).

4. A laser device capable of processing high reflective materials according to claim 3, wherein the reflective optical attenuator (11) comprises a reflected light attenuation section composed of an input optical fiber, a middle optical fiber and an output optical fiber, wherein the reflected light is transmitted in the following directions: 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 and the terminal of the output section optical fiber.

5. The high reflectivity material processable laser device of claim 4, wherein the reflective optical attenuator (11) is operable to input core reflected light through the input section fiber, the mode field area of the core reflected light gradually increases from the input section fiber to the core mode field area of the middle section fiber when passing through the tapers of the input and middle section fibers, and gradually decreases to the core mode field area of the output section fiber when passing through the tapers of the middle and output section fibers.

6. The laser device capable of processing high-reflectivity materials as claimed in claim 5, wherein the forward combiner (4) signal fiber is 20 μm core and 400 μm cladding, i.e. the forward combiner (4) signal fiber is 20/400 double-clad fiber core, the coating layer is 530 μm, and the NA is 0.07;

the input section of the reflecting optical attenuator (11) is 20/400 double-clad optical fiber, and the core NA is 0.07;

the output section optical fiber is 20/400 double-clad optical fiber, and the core NA is 0.07.

7. The laser device capable of processing high-reflectivity material as claimed in claim 6, wherein the beam combiner signal fiber is 20/400 double-clad fiber, and the core NA is 0.07;

the input section of the reflecting optical attenuator (11) is 20/400 double-clad optical fiber, and the NA of a fiber core is 0.07;

the middle section of the optical fiber is 50/70/360 triple-clad optical fiber, and the NA of a fiber core is 0.22;

the output section of the optical fiber is 20/400 double-clad optical fiber, and the core NA is 0.07.

8. The laser device capable of processing high-reflectivity material as claimed in claim 7, wherein the beam combiner signal fiber is 14/250 double-clad fiber, and the core NA is 0.07;

the input section of the reflecting optical attenuator (11) is 14/250 double-clad optical fiber, and the NA of a fiber core is 0.07;

the output section of the optical fiber is 12/250 double-clad optical fiber, and the core NA is 0.07.

9. The laser device capable of processing high-reflectivity materials as claimed in any one of claims 6 to 8, wherein the reflective optical attenuator (11) is further provided with a photothermal conversion wall (12) at the outside, a cold water pipe (13) is provided at the outside of the photothermal conversion wall (12), and after the core reflected light passes through the photothermal conversion wall (12), the heat energy of the core reflected light is conducted to the inner layer of the photothermal conversion wall (12), and the heat energy is conducted out through water via the cold water pipe (13).

10. The reflected light processing method according to claim 9, wherein the photothermal conversion wall (12) is formed with a fiber fixing hole (14), and the reflected light attenuation section is passed through and fixed in the fiber fixing hole (14).

11. A reflected light processing method, characterized in that the processing method can be realized by a laser device capable of processing a high-reflective material according to any one of claims 1 to 10.

12. The reflected light processing method according to claim 11, comprising:

step S10, when the laser device is started and any material is not processed, the pump source emits pump laser, the pump laser is coupled into a single fiber cladding through a forward/backward beam combiner, the cladding pump laser is converted into fiber core fiber laser in a resonant cavity formed by a high/low-reflection grating and a gain fiber, and the laser is output from a fiber output device (10) after the residual cladding light is stripped through a stripper;

step S20, when the laser device processes material, a large amount of reflected light is coupled back to the light path of the laser device again by the principle of light path reciprocal and transmitted along the light path reversely, wherein the reflected light coupled into the cladding is stripped completely by the stripper, part of the reflected light of the fiber core is coupled into the cladding when passing through the beam combiner and stripped by the stripper, the residual reflected light of the fiber core still reaches the hundred watt level, at this time, the reflection optical attenuator (11) works to couple the reflected light of the fiber core into the cladding and strip, wherein, the material comprises high-reflectivity material, and the action of processing the material comprises cutting and welding.

13. The reflected light processing method according to claim 12, wherein step S20 includes:

step S201, emitting a laser beam of an optical fiber output device (10) to the surface of a high-reflection material, coupling reflected light reflected from the surface of the high-reflection material into a fiber core of an optical fiber to obtain fiber core reflected light, and transmitting the fiber core reflected light along a light path of a laser device in a reverse direction;

step S202, when the reflection optical attenuator (11) works, the fiber core reflected light sequentially passes through the cone regions of the input section optical fiber and the middle section optical fiber;

step S203, stripping most of the core reflected light coupled into the cladding by using a reverse mode stripper (2) to strip the cladding of the tapered and output section optical fiber.