Fiber laser, integrated laser output device and manufacturing method thereof

Abstract

The invention relates to an optical fiber laser, an integrated laser output device and a manufacturing method of the integrated laser output device, and the integrated laser output device sequentially comprises an input section, a transition section and an output section along the transmission direction of laser. The input section sequentially comprises an input fiber core and an input cladding from inside to outside in the radial direction. The input fiber core and the output fiber core of the laser generator have the same diameter and are coaxial, and the input cladding and the cladding of the output fiber have the same outer diameter and are coaxial. The transition section sequentially comprises a transition fiber core and a transition cladding from inside to outside in the radial direction. The input end of the transition fiber core and the input fiber core have the same diameter and are coaxial. And the diameter of the transition fiber core is gradually increased along the laser transmission direction. The output section sequentially comprises an output fiber core and an output cladding from inside to outside in the radial direction. The output fiber core and the output end of the transition fiber core have the same diameter and are coaxial. When laser is transmitted along the transition fiber core and the output fiber core, gaps exist between the laser and the peripheral walls of the transition fiber core and the output fiber core. And the input section and the output optical fiber of the laser generator can be welded in the same diameter.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber lasers, and in particular to an optical fiber laser, an integrated laser output device and a manufacturing method thereof. Background Art

[0002] Fiber lasers use an all-fiber structure. To prevent the output fiber’s laser power from being too high and damaging the output end face, the output end of the output fiber is currently generally fused to a quartz end cap to expand the laser beam and reduce the power through the end cap, thereby achieving safe laser output.

[0003] The input end of the end cap needs to be as close as possible to the diameter of the optical fiber so that the optical fiber and the end cap can be smoothly welded. The diameter of the output end of the end cap is larger to meet the laser distribution after beam expansion. The existing end cap has a small diameter at one end and a large diameter at the other end. Since the end cap is generally made of fused silica blanks by cold processing, when the size is too small, the fused silica will become soft and cannot be cold processed. This limits the lower limit of the diameter of the input end of the end cap. Under the condition of ensuring the yield, the diameter of the end cap cannot be less than 1000μm, while the cladding diameter of the common output optical fiber is less than 500μm, that is, the input end diameter of the end cap is more than twice the diameter of the output optical fiber. The welding quality of the different diameter welding between the input end of the end cap and the output optical fiber, including position positioning, welding strength, and welding morphology, is difficult to guarantee. After welding, there are problems such as energy distribution distortion, laser quality deterioration, and output pointing angle deviation, which in turn affects the energy distribution, laser quality, and output pointing angle of the laser when it is transmitted between the output optical fiber and the end cap. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides an integrated laser output device and a method for manufacturing the same, which solves the technical problem in the prior art that it is difficult to ensure the quality of the welding of optical fibers and end caps with different diameters, and that energy distribution distortion, laser quality deterioration and output pointing angle deviation are prone to occur after welding, thereby affecting the energy distribution, laser quality and output pointing angle performance of the laser when it is transmitted between the output optical fiber and the end cap.

[0006] (II) Technical solution

[0007] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0008] In a first aspect, the present invention provides an integrated laser output device, which includes an input section, a transition section and an output section in sequence along the transmission direction of the laser;

[0009] The input section includes an input fiber core and an input cladding in sequence from the inside to the outside in the radial direction; the input fiber core is consistent with the core diameter of the output fiber of the laser generator and is coaxial, and the input cladding is consistent with the outer diameter of the cladding of the output fiber and is coaxial;

[0010] The transition section includes a transition core and a transition cladding in sequence from the inside to the outside in the radial direction; the input end of the transition core is consistent with the diameter of the input core and is coaxial; along the transmission direction of the laser, the diameter of the transition core gradually increases;

[0011] The output section includes an output fiber core and an output cladding in sequence from the inside to the outside in the radial direction; the output fiber core and the output end of the transition fiber core have the same diameter and are coaxial;

[0012] When the laser is transmitted along the transition fiber core and the output fiber core, there is a gap between the laser and the peripheral walls of the transition fiber core and the output fiber core.

[0013] According to the present invention, the input fiber core, the transition fiber core and the output fiber core can be consistent with the numerical aperture of the core of the output optical fiber;

[0014] The numerical aperture satisfies the following formula:

[0015] NA=n co sinθ max ;

[0016] θ<θ max ;

[0017] Among them, n co is the refractive index of the laser when it is transmitted in the input fiber core, the transition fiber core and the output fiber core, θ is the divergence angle of the laser, θ max is the maximum divergence angle of the laser that can be transmitted by the input fiber core, the transition fiber core and the output fiber core.

[0018] According to the present invention, the overall length L of the transition section and the output section satisfies the following formula:

[0019] ρ<beam damage threshold of the output surface of the output section;

[0020] ρ=P / π·r2 2 ;

[0021] r2=r co +Ltanθ;

[0022] Among them, r co is the radius of the input fiber core, r is the spot radius of the laser reaching the output surface of the output section, ρ is the power density of the laser reaching the output surface of the output section, P is the laser power, and θ is the divergence angle of the laser.

[0023] According to the present invention, the diameters D of the transition fiber core and the output fiber core satisfy the following formula:

[0024] D>r;

[0025] r1=r co +L1 tanθ;

[0026] Among them, r co is the radius of the input fiber core, r is the spot radius of the radial section of the laser reaching the transition fiber core or the output fiber core, L1 is the distance between the radial section of the laser reaching the or the output fiber core and the input end of the output fiber core, and θ is the divergence angle of the laser.

[0027] According to the present invention, the peripheral wall of the transition fiber core is arc-shaped along its axial direction.

[0028] According to the present invention, an anti-reflection film is provided on the output surface of the input section, and the transmittance of the laser when emitted from the anti-reflection film is ≥99.8%.

[0029] According to the present invention, the input section further comprises a coating layer coated on the input cladding;

[0030] There is a gap between the coating layer and the output end of the input cladding, and a roughened structure is arranged on the periphery of the input cladding where the coating layer is not arranged.

[0031] According to the present invention, the transition cladding and the output cladding have various shapes and sizes.

[0032] In a second aspect, the present invention further provides a fiber laser, comprising the integrated laser output device and a laser generator;

[0033] The input end of the input section is fused with the output end of the output optical fiber of the laser generator in the same diameter.

[0034] In a third aspect, the present invention further provides a method for manufacturing an integrated laser output device, which is used to manufacture the integrated laser output device, comprising the following steps:

[0035] An optical fiber preform having a core-to-clad ratio and a numerical aperture consistent with those of the output optical fiber is heated to a molten state, and after retaining a certain length of the optical fiber preform to form the output section, the remaining optical fiber preform of a set length is drawn in a manner of gradually reducing the diameter to form the transition section, and then the remaining optical fiber preform is drawn with equal diameter to form the input section, so that the input fiber core of the input section is consistent with and coaxial with the diameter of the output optical fiber, and the input cladding is consistent with and coaxial with the outer diameter of the output optical fiber.

[0036] (III) Beneficial effects

[0037] The beneficial effects of the present invention are as follows: the integrated laser output device of the present invention has an input section with a core diameter consistent with and coaxial with the output optical fiber of the laser generator, and an input cladding with an outer diameter consistent with and coaxial with the cladding of the output optical fiber, so that the input section and the output optical fiber of the laser generator can be fused with the same diameter, replacing the existing technology of different-diameter fusion of the optical fiber and the end cap, and can eliminate the problems of energy distribution distortion, laser quality deterioration, output pointing angle deviation, etc. caused by different-diameter fusion, thereby ensuring the fusion quality and laser transmission quality.

[0038] At the same time, when the integrated laser output device is used, the laser in the output optical fiber of the laser generator is transmitted to the input fiber core of the input section and continues to be transmitted forward in a total reflection manner. When the laser is transmitted to the interface between the input section and the transition section, since the diameter of the transition fiber core of the transition section gradually increases, the laser expands according to its divergence angle and there is a gap with the peripheral wall of the transition fiber core without contacting and reflecting. Therefore, the laser can be transmitted forward in a beam expansion manner. When the laser is transmitted to the output section, the diameter of the output fiber core of the output section is still larger than the spot diameter of the laser reaching the radial cross section of the output fiber core. There is still a gap between the laser and the peripheral wall of the output fiber core without contacting and reflecting. Therefore, the laser continues to be transmitted forward according to the diameter after the divergence angle expansion until it reaches the output surface of the output section, so as to expand the beam and reduce the power density, and enable the laser to safely emit the output surface without damaging the output surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic diagram of Example 1 of the integrated laser output device of the present invention;

[0040] Figure 2 for Figure 1 Schematic diagram of removing part of the transition cladding and output cladding;

[0041] Figure 3 Schematic diagram of optical fiber preform.

[0042] [Description of Reference Numerals]

[0043] 1: input section; 11: input core; 12: input cladding; 121: hairline structure; 13: coating layer;

[0044] 2: transition section; 21: transition core; 22: transition cladding;

[0045] 3: output section; 31: output fiber core; 32: output cladding; 33: anti-reflection film;

[0046] 4: optical fiber preform; 41: core glass; 42: cladding glass;

[0047] A: Laser. DETAILED DESCRIPTION

[0048] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0049] See also Figure 1 The integrated laser output device proposed in the embodiment of the present invention is an integrated device, which includes an input section 1, a transition section 2 and an output section 3 in sequence along the transmission direction of the laser A.

[0050] The input section 1 includes an input fiber core 11 and an input cladding 12 in sequence from the inside to the outside in the radial direction. The input fiber core 11 is consistent with the core diameter of the output fiber of the laser generator, and the input cladding 12 is consistent with and coaxial with the cladding outer diameter of the output fiber. The transition section 2 includes a transition fiber core 21 and a transition cladding 22 in sequence from the inside to the outside in the radial direction. The input end of the transition fiber core 21 is consistent with and coaxial with the diameter of the input fiber core 11. Along the transmission direction of the laser A, the diameter of the transition fiber core 21 gradually increases. The output section 3 includes an output fiber core 31 and an output cladding 32 in sequence from the inside to the outside in the radial direction. The output fiber core 31 is consistent with and coaxial with the output end of the transition fiber core 21. When the laser A is transmitted along the transition fiber core 21 and the output fiber core 31, there is a gap between the laser A and the peripheral walls of the transition fiber core 21 and the output fiber core 31.

[0051] In the integrated laser output device, the core diameter of the input section 1 is consistent with and coaxial with the output optical fiber of the laser generator, and the outer diameter of the input cladding 12 is consistent with and coaxial with the cladding of the output optical fiber, so that the input section 1 and the output optical fiber of the laser generator can be fused with the same diameter, replacing the existing technology of different-diameter fusion of optical fiber and end cap, and can eliminate the problems of energy distribution distortion, laser quality deterioration, output pointing angle deviation and the like caused by different-diameter fusion, thereby ensuring the fusion quality and laser transmission quality.

[0052] At the same time, when the integrated laser output device is used, the laser in the output optical fiber of the laser generator is transmitted to the input fiber core 11 of the input section 1 and continues to be transmitted forward in a total reflection manner. When the laser A is transmitted to the interface between the input section 1 and the transition section 2, since the diameter of the transition fiber core 21 of the transition section 2 gradually increases, the laser A has a gap with the peripheral wall of the transition fiber core 21 after being expanded according to its divergence angle, but does not contact and reflect. Therefore, the laser A can be transmitted forward with expanded beam. When the laser A is transmitted to the output section 3, the diameter of the output fiber core 31 of the output section 3 is still larger than the spot diameter of the laser A reaching the radial cross section of the output fiber core 31. There is still a gap between the laser A and the peripheral wall of the output fiber core 31, but does not contact and reflect. Therefore, the laser A continues to be transmitted forward according to the diameter after the divergence angle expansion until it reaches the output surface of the output section 3, so as to expand the beam and reduce the power density, and make the laser A safely emit the output surface without damaging the output surface.

[0053] Furthermore, in this integrated laser output device, since the transition core 21 in the transition section 2 is a variable diameter structure, when the returning laser A enters the output core 31 from the output surface of the output section 3 and enters the transition core 21 of the transition section 2, the returning laser A will contact the surrounding wall of the transition core 21 multiple times during transmission and undergo multiple reflections to change its transmission direction, thereby greatly reducing the amount of returning light entering the input optical fiber of the input section 1, thereby protecting the laser transmission optical path of the input core 11 of the input section 1.

[0054] Furthermore, in order to achieve the smooth output of laser A, the input fiber core 11, the transition fiber core 21 and the output fiber core 31 can be consistent with the numerical aperture of the core of the output optical fiber, so that the laser A with a specific divergence angle transmitted by the core of the output optical fiber can smoothly enter and be transmitted forward in the input fiber core 11, the transition fiber core 21 and the output fiber core 31 in sequence.

[0055] Specifically, the input fiber core 11, the transition fiber core 21 and the output fiber core 31 can be consistent with the numerical aperture of the core of the output optical fiber, so that the integrated laser output device can support the laser A with a specific divergence angle θ output by the output optical fiber of the laser generator to be transmitted in the input fiber core 11, the transition fiber core 21 and the output fiber core 31 in sequence, and the numerical aperture needs to satisfy the following formula:

[0056] NA=n co sinθ max ;

[0057] θ<θ max ;

[0058] Among them, n co is the refractive index of laser A when it is transmitted in the input fiber core 11, the transition fiber core 21 and the output fiber core 31, θ is the divergence angle of laser A, θ max It is the maximum divergence angle of the laser A that can be transmitted by the input fiber core 11, the transition fiber core 21 and the output fiber core 31.

[0059] It should be noted that the input fiber core 11 , the transition fiber core 21 and the output fiber core 31 are made of the same material, and their refractive indices and the maximum divergence angles of the laser light A that can be transmitted are all the same.

[0060] Furthermore, in order to ensure that the power density of the laser A when it reaches the output surface of the output section 3 is less than the laser damage threshold of the output surface of the output section 3 to avoid damaging the output surface, the overall length L of the transition section 2 and the output section 3 needs to satisfy the following formula:

[0061] ρ<beam damage threshold of the output surface of the output section;

[0062] ρ=P / π·r2 2 ;

[0063] r2=r co +Ltanθ;

[0064] Among them, r co is the radius of the input fiber core 11, r2 is the spot radius of the laser A reaching the output surface of the output section 3, ρ is the power density of the laser A reaching the output surface of the output section 3, P is the laser power, and θ is the divergence angle of the laser A.

[0065] Furthermore, in order to ensure that the laser A can be expanded and transmitted according to its divergence angle when transmitting in the transition fiber core 21 and the output fiber core 31, the diameter D of the transition fiber core 21 and the output fiber core 31 needs to satisfy the following formula:

[0066] D>2r1;

[0067] r1=r co +L1 tanθ;

[0068] Among them, r co is the radius of the input fiber core 11, r1 is the spot radius of the radial section of the laser A reaching the transition fiber core 21 or the output fiber core 31, L1 is the distance between the radial section of the laser A reaching the transition fiber core 21 or the output fiber core 31 and the input end of the output fiber core 31, and θ is the divergence angle of the laser A.

[0069] Therefore, when laser A is transmitted in the transition fiber core 21 and the output fiber core 31 to a certain position of the transition fiber core 21 or the output fiber core 31, the spot diameter of the radial cross section of laser A on the transition fiber core 21 or the output fiber core 31 is kept smaller than the diameter of the radial cross section on the transition fiber core 21 or the output fiber core 31, so that laser A does not contact the peripheral wall of the transition fiber core 21 or the output fiber core 31, and is transmitted in an expanded beam according to its divergence angle.

[0070] Furthermore, in order to reduce Fresnel reflection when laser A is emitted from the output surface of output section 3, the output surface of input section 1 is coated with an anti-reflection film 33 for the laser wavelength, so that the transmittance of laser A at this wavelength when emitted from anti-reflection film 33 is ≥99.8%.

[0071] Furthermore, the input section 1 further includes a coating layer 13 coated on the input cladding 12. Since the input section 1 is thin, soft and brittle, the coating layer 13 can effectively protect the input section 1 from being broken or damaged. Optionally, the coating layer 13 can be an epoxy coating layer 13, an acrylic resin coating layer 13 or the like.

[0072] Furthermore, there is a gap between the coating layer 13 and the output end of the input cladding 12, and a roughened structure 121 is provided on the periphery of the input cladding 12 where the coating layer 13 is not provided, so as to filter out invalid laser light entering the input cladding 12 from the input fiber core 11, including forward stray light and reverse return light, thereby improving the transmission quality of the laser A from the input fiber core 11 into the transition fiber core 21.

[0073] Optionally, the outer periphery of the input cladding 12 where the coating layer 13 is not provided is roughened by chemical corrosion or laser etching.

[0074] Optionally, the length of the gap is 5-10 cm.

[0075] Preferably, the diameters of the output end of the transition fiber core 21 and the output fiber core 31 are consistent and coaxial, and are not less than 8 mm, which can be larger than the spot diameter of most lasers A when output from the output end of the output fiber core 31, meeting the beam expansion output requirements of laser A.

[0076] Preferably, the outer diameter of the input cladding 12 is 200-500 μm, which is consistent with the outer diameter of the cladding of the output optical fiber of most laser generators and meets the requirement of the same-diameter fusion splicing of the input section 1 and the output optical fiber.

[0077] See also Figure 2 Preferably, since the laser A is expanded and transmitted in the transition fiber core 21 and the output fiber core 31, but not transmitted to the transition cladding 22 and the output cladding 32, the transition cladding 22 and the output cladding 32 can have a variety of shapes and sizes. By removing part of the transition cladding 22 and the output cladding 32, their shapes and sizes can be matched with packaging mechanisms of different shapes and sizes for covering the transition cladding 22 and the output cladding 32.

[0078] More preferably, parts of the transition cladding 22 and the output cladding 32 may be removed by grinding.

[0079] Furthermore, the peripheral wall of the transition core 21 is arc-shaped along its axial direction, so as to facilitate shaping during high-temperature drawing.

[0080] Referring to 1-3, further, the manufacturing method of the integrated laser output device includes the following steps:

[0081] S1: The optical fiber preform 4 having a core-to-clad ratio and a numerical aperture consistent with those of the output optical fiber is heated to a molten state, and after retaining a certain length of the optical fiber preform 4 to form an output section 3, the remaining optical fiber preform 4 of the set length is drawn in a manner of gradually reducing the diameter to form a transition section 2, and then the remaining optical fiber preform 4 is drawn with equal diameter to form an input section 1, so that the input fiber core 11 of the input section 1 is consistent with the diameter of the output optical fiber and is coaxial, and the input cladding 12 is consistent with the outer diameter of the cladding of the output optical fiber and is coaxial.

[0082] S2: After a set length is reserved at the output end of the input cladding 12, a coating layer 13 is formed by coating, and the outer periphery of the input cladding 12 where the coating layer 13 is not provided is roughened.

[0083] S3: grinding and removing a part of the transition cladding 22 and the output cladding 32 so that the shape and size of the transition cladding 22 and the output cladding 32 can match the packaging mechanism.

[0084] Among them, an optical fiber preform 4 having a core-to-clad ratio and a numerical aperture consistent with those of the output optical fiber is used, so that the optical fiber preform 4 can be drawn into an input fiber core 11, a transition fiber core 21 and an output fiber core 31 with the same numerical aperture to support the transmission of a laser A with a specific divergence angle. At the same time, the drawn input fiber core 11 can be consistent with the core diameter of the output optical fiber and be coaxial, the input cladding 12 can be consistent with the cladding outer diameter of the output optical fiber and be coaxial, and the core-to-clad ratio of the input fiber core 11 and the input cladding 12 can be consistent with the core-to-clad ratio of the output optical fiber, so that the input segment 1 can have a core-to-clad ratio consistent with that of the output optical fiber.

[0085] Furthermore, the input fiber core 11, the transition fiber core 21 and the output fiber core 31 are formed by drawing from an optical fiber preform rod 4, so the materials of the three are consistent, and the refractive indices of the three and the maximum divergence angles of the laser A that can be transmitted are also consistent.

[0086] Specifically, the optical fiber preform 4 includes a core glass 41 and a cladding glass 42 in sequence from the inside to the outside along the radial direction.

[0087] Example 2

[0088] Based on the first embodiment, this embodiment further provides a fiber laser, which includes an integrated laser output device and a laser generator. An output fiber is arranged inside the laser generator.

[0089] The input end of the input section 1 is fused with the output end of the output optical fiber of the laser generator in the same diameter, which ensures the fusion quality between the input section 1 and the output optical fiber, and ensures the laser transmission quality when the laser A is output from the output optical fiber to the input section 1.

[0090] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 directly connected or indirectly connected 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 present invention can be understood according to the specific circumstances.

[0091] In the present invention, unless otherwise clearly specified and limited, when a first feature is “on” or “below” a second feature, it may be that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, when a first feature is “above”, “above” or “above” a second feature, it may be that the first feature is directly above or obliquely above the second feature, or it may simply mean that the first feature is higher in level than the second feature. When a first feature is “below”, “below” or “below” a second feature, it may be that the first feature is directly below or obliquely below the second feature, or it may simply mean that the first feature is lower in level than the second feature.

[0092] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0093] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An integrated laser output device, characterized in that: Along the transmission direction of the laser (A), it includes an input section (1), a transition section (2) and an output section (3); The input section (1) includes an input fiber core (11) and an input cladding (12) in sequence from the inside to the outside in the radial direction; the input fiber core (11) is consistent with and coaxial with the core diameter of the output optical fiber of the laser generator, and the input cladding (12) is consistent with and coaxial with the outer diameter of the cladding of the output optical fiber; The transition section (2) includes a transition core (21) and a transition cladding (22) in sequence from the inside to the outside in the radial direction; the input end of the transition core (21) has the same diameter as the input core (11) and is coaxial; along the transmission direction of the laser (A), the diameter of the transition core (21) gradually increases; The output section (3) includes an output fiber core (31) and an output cladding (32) in sequence from the inside to the outside along the radial direction; the output fiber core (31) and the output end of the transition fiber core (21) have the same diameter and are coaxial; When the laser light (A) is transmitted along the transition fiber core (21) and the output fiber core (31), a gap exists between the laser light (A) and the peripheral walls of the transition fiber core (21) and the output fiber core (31).

2. The integrated laser output device according to claim 1, characterized in that: The input fiber core (11), the transition fiber core (21) and the output fiber core (31) can be consistent with the numerical aperture of the fiber core of the output optical fiber; The numerical aperture satisfies the following formula: NA=n co sinθ max ; θ<θ max ; Among them, n co is the refractive index of the laser (A) when it is transmitted in the input fiber core (11), the transition fiber core (21) and the output fiber core (31), θ is the divergence angle of the laser (A), and θ max is the maximum divergence angle of the laser light (A) that can be transmitted by the input fiber core (11), the transition fiber core (21) and the output fiber core (31).

3. The integrated laser output device according to claim 1, characterized in that: The overall length L of the transition section (2) and the output section (3) satisfies the following formula: ρ<beam damage threshold of the output surface of the output section; ρ=P / π·r2 2 ; r2=r co +Ltanθ; Among them, r co is the radius of the input fiber core (11), r2 is the spot radius of the laser (A) reaching the output surface of the output section (3), ρ is the power density of the laser (A) reaching the output surface of the output section (3), P is the power of the laser (A), and θ is the divergence angle of the laser (A).

4. The integrated laser output device according to claim 1, characterized in that: The diameters D of the transition fiber core and the output fiber core satisfy the following formula: D＞2r1； r1=r co +L1 tanθ; Among them, r co is the radius of the input fiber core (11), r1 is the spot radius of the radial cross section of the laser (A) reaching the transition fiber core (21) or the output fiber core (31), L1 is the distance between the radial cross section of the laser (A) reaching the (21) or the output fiber core (31) and the input end of the output fiber core (31), and θ is the divergence angle of the laser (A).

5. The integrated laser output device according to claim 1, characterized in that: The peripheral wall of the transition fiber core (21) is arc-shaped along its axial direction.

6. The integrated laser output device according to claim 1, characterized in that: An anti-reflection film (33) is provided on the output surface of the input section (1), and the transmittance of the laser (A) when emitted from the anti-reflection film (33) is ≥99.8%.

7. The integrated laser output device according to claim 1, characterized in that: The input section (1) further comprises a coating layer (13) coated on the input cladding (12); There is a gap between the coating layer (13) and the output end of the input cladding (12), and a roughened structure (121) is provided on the periphery of the input cladding (12) where the coating layer (13) is not provided.

8. The integrated laser output device according to claim 1, characterized in that: The transition cladding (22) and the output cladding (32) have various shapes and sizes.

9. A fiber laser, characterized in that: The integrated laser output device according to any one of claims 1 to 8 further comprises a laser generator; The input end of the input section (1) is fused with the output end of the output optical fiber of the laser generator in the same diameter.

10. A method for manufacturing an integrated laser output device, used for manufacturing the integrated laser output device according to any one of claims 1 to 8, characterized in that: The steps include: An optical fiber preform (4) having a core-to-clad ratio and a numerical aperture consistent with those of the output optical fiber is heated to a molten state, and after retaining a certain length of the optical fiber preform (4) to form the output section (3), the remaining optical fiber preform (4) of a set length is drawn in a manner of gradually reducing the diameter to form the transition section (2), and then the remaining optical fiber preform (4) is drawn in a constant diameter to form the input section (1), so that the input fiber core (11) of the input section (1) is consistent with and coaxial with the diameter of the output optical fiber, and the input cladding (12) is consistent with and coaxial with the outer diameter of the cladding of the output optical fiber.

Images