Tunable focusing device and focusing method for high-power semiconductor laser

Abstract

The invention discloses a tunable focusing device for a high-power semiconductor laser. The tunable focusing device comprises a semiconductor laser coupling head, a bottom plate and a lens base, the semiconductor laser coupling head is coupled with an output optical fiber of the semiconductor laser to ensure laser input, is provided with a water inlet and a water outlet and is connected with a cooling water pipe to ensure stable operation under a high-power condition, the bottom plate comprises a sliding groove, and the width of the lens base is matched with the width of the sliding groove of the bottom plate. And by introducing cooling water and adjusting the position of the lens base, the adjustable output of the imaging proportion of the high-power semiconductor laser can be realized, and the high-power semiconductor laser has good practicability.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, and in particular to a tunable focusing device and a focusing method for a high-power semiconductor laser. Background Art

[0002] Since the advent of the world's first ruby ​​laser, laser technology has achieved rapid development. As one of the core components of the laser, the choice of pump source directly affects the output power, wavelength and working stability of the laser. Semiconductor lasers have the characteristics of small size, low cost and high stability. Especially in recent years, the rapid development of high-power 981nm semiconductor lasers and the continuous emergence of various types of ytterbium-doped laser crystals have made semiconductor lasers an indispensable pump source in ytterbium-doped laser systems.

[0003] However, currently, high-power semiconductor lasers generally use optical fiber output, and their beam quality is easily affected by temperature changes, and there is a lack of effective thermal management methods, which to a certain extent limits their full performance. In addition, when using semiconductor lasers as pump sources, they usually need to be focused through a lens group consisting of two lenses to obtain the required size of the pump spot. However, this process requires extremely high precision in the position of the lens, and fine adjustments are required to ensure that the ellipticity of the focused spot is close to 1, which increases the time cost of alignment and reduces production efficiency.

[0004] More importantly, the existing lens group has poor tunability. When the size of the focused spot needs to be adjusted, tedious readjustment is often required, which undoubtedly further increases the difficulty and time cost of operation.

[0005] Therefore, in response to these problems existing in the existing technology, there is an urgent need for a new pump source or focusing system that can effectively improve the beam quality, reduce the alignment time cost, and enhance the tunability, so as to meet the urgent demand for high-performance pump sources in application fields such as ytterbium-doped laser systems. Summary of the invention

[0006] In view of the difficulty in focusing the output light spot of the semiconductor laser mentioned above, the present invention proposes a tunable focusing device for a high-power semiconductor laser.

[0007] The technical solution of the present invention is as follows:

[0008] A tunable focusing device for high-power semiconductor lasers, characterized in that it comprises a semiconductor laser coupling head, a base plate, a lens holder, an optical fiber fixing head and a lens;

[0009] The bottom plate is provided with a sliding groove adapted to the lens holder, and a threaded hole is provided in the sliding groove;

[0010] The bottom of the lens holder is provided with a sliding opening for fixing with the sliding groove; the top is provided with a step to increase the fixing stability;

[0011] The semiconductor laser coupling head is provided with fixing grooves on both sides, and the semiconductor laser coupling head is fixed to the bottom plate by screws, and the output optical fiber of the semiconductor laser is connected to the optical fiber fixing head to realize laser input;

[0012] The semiconductor laser coupling head is provided with a threaded water inlet and a water outlet for connecting a water pipe quick plug and accessing a cooling water system. Heat dissipation ensures the stability of the output light spot mode when the high-power semiconductor laser is running. The semiconductor laser coupling head is also provided with a plugging thread, which is coupled with a screw of a corresponding aperture to prevent water from overflowing from the plugging when cooling water is introduced from the water inlet.

[0013] Furthermore, the width of the sliding groove is equal to the width of the lens seat, and the size of the focusing spot is adjusted by sliding the position of the lens seat in the sliding groove, and the height of the lens seat ensures that the center height of the lens is consistent with the height of the output beam of the semiconductor laser coupling head.

[0014] Further, the lens holder includes a first lens holder and a second lens holder, and the lens includes a first lens and a second lens;

[0015] Further, the lens is a plano-convex lens or a plano-concave lens;

[0016] Furthermore, the plane side of the lens is closely attached to the step and fixed to the lens holder through thermally conductive silicone to ensure its fixing stability and good thermal conductivity;

[0017] Furthermore, there is an array of threaded holes with equal distances in the middle of the sliding groove, and the opening size of the sliding opening is equal to the diameter of the threaded hole. The size of the focused light spot can be conveniently adjusted by sliding the position of the lens holder, and the height of the lens holder should ensure that the center height of the lens is consistent with the height of the output light beam of the semiconductor laser coupling head;

[0018] Furthermore, the sliding groove has a built-in intelligent indication system, which is combined with the threaded hole array and the sliding opening to assist the user in quickly and accurately adjusting the position of the lens mount through digital display, thereby improving the adjustment efficiency and accuracy.

[0019] Furthermore, the intelligent indication system integrates a remote control interface, allowing the user to remotely monitor and adjust the position of the lens mount through an external device, thereby realizing intelligent control of the focus spot size.

[0020] On the other hand, the present invention also provides a tunable focusing method for a high-power semiconductor laser using the above device, which is characterized in that it comprises the following steps:

[0021] 1) Fix the semiconductor laser coupling head on the base plate by screws, and connect the output optical fiber of the semiconductor laser to the optical fiber fixing head, so as to realize the laser input of the semiconductor laser.

[0022] 2) Connect the water pipe to the water inlet and outlet of the semiconductor laser coupling head, and use screws with corresponding apertures to couple the plugging threads to ensure that no water overflows from the plugging threads while the cooling water is introduced.

[0023] 3) According to the core diameter of the semiconductor laser output optical fiber, the diameter of the focused light spot is determined, and then the focal lengths of the first lens and the second lens and their positions relative to the semiconductor laser output coupling head are calculated.

[0024] 4) By using an external remote device to monitor the built-in intelligent indication system, place the first lens mount and the second lens mount at the calculated position, and then fix the screws through the sliding opening and into the threaded holes on the base plate.

[0025] 5) When the focus spot size needs to be changed, the intelligent indication system is used to monitor and repeat steps 3) and 4), thereby realizing the focus spot tunable function.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] 1. The semiconductor laser coupling head is equipped with a threaded water inlet and outlet for connecting the water pipe to the cooling water system. The plugging thread is coupled with a screw of the corresponding aperture, and a self-locking safety valve can be optionally provided to ensure that no water will overflow from the plugging when cooling water is introduced from the water inlet. This not only improves the cooling effect, but also increases the safety of the device, and can ensure the stability of the output spot of the high-power semiconductor laser.

[0028] 2. The size of the focused light spot is adjusted by sliding the position of the lens holder in the sliding groove, and the height design of the lens holder ensures that the center height of the lens is consistent with the height of the output beam of the semiconductor laser coupling head, so that the device reduces the time cost of optical path alignment, increases the tunability of the focused light spot size, can adapt to the needs of different application scenarios, and improves its flexibility and practicality.

[0029] 3. The lens mount is tightly fitted to the step in all directions through high-performance thermal conductive silicone, which not only ensures extremely high fixing stability, but also provides heat dissipation performance, effectively prolongs the service life of the device, and ensures the stability of the output spot mode under high-power operation.

[0030] 4. An intelligent indication system is integrated, which is combined with the threaded hole array in the sliding groove and the sliding opening of the lens holder to assist users in quickly and accurately adjusting the position of the lens holder through digital display. This intelligent design not only improves the adjustment efficiency and accuracy, but also allows users to more intuitively understand the current position status of the lens holder. The intelligent indication system further integrates a remote control interface, allowing users to remotely monitor and adjust the position of the lens holder through external devices, so that users can achieve intelligent control of the focus spot size without direct contact with the device, thereby improving the convenience and safety of operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The figure is a schematic diagram of the structure of the tunable focusing device for high-power semiconductor laser of the present invention.

[0032] Figure 2 The figure is a schematic top view at 45 degrees of a lens holder of a tunable focusing device for a high-power semiconductor laser according to the present invention.

[0033] Figure 3 The figure is a top view schematic diagram of a lens holder of a tunable focusing device for a high-power semiconductor laser according to the present invention.

[0034] Figure 4 The figure is a schematic diagram of the internal water path of the semiconductor laser coupling head of the tunable focusing device for high-power semiconductor lasers of the present invention.

[0035] In the figure: semiconductor laser coupling head 1, base plate 2, lens holder 3, sliding groove 4, optical fiber fixing head 5, water inlet 6, water outlet 7, plugging thread 8, threaded hole 9, sliding opening 10, step 11, fixing groove 12, lens 13. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0037] See also Figure 1-4As shown in the figure, a tunable focusing device for a high-power semiconductor laser comprises: a semiconductor laser coupling head 1, which has fixing grooves 12 on both sides, and the semiconductor laser coupling head 1 is firmly and accurately fixed on the bottom plate 2 by fine-tuning screws to ensure high-precision alignment of the laser with subsequent optical components; the output optical fiber of the semiconductor laser is seamlessly connected through a high-precision optical fiber fixing head 5 to ensure efficient and stable input of the laser. A water inlet 6 and a water outlet 7 are also provided on the semiconductor laser coupling head 1. The water inlet 6 and the water outlet 7 are both threaded, and the water pipe quick plug is coupled with them, and then connected to the water inlet and water outlet water pipes of corresponding apertures. The plugging thread 8 is coupled with the screw of the corresponding aperture to ensure that when cooling water is introduced from the water inlet, no water flow overflows from the plugging. The introduction of cooling water can ensure the stability of the output spot mode under high-power operation. The plugging thread 8 can also be equipped with a self-locking safety valve, which automatically closes when the cooling water pressure is abnormal to double-protect no water flow overflow, effectively maintaining the stability of the spot mode during high-power operation.

[0038] It also includes: a lens holder 3, which has a step 11 therein, and the side and plane sides of the lens 13 are respectively closely fitted with the lens holder 3 and the step 11 in all directions through high-performance thermal conductive silicone, which not only ensures extremely high fixing stability, but also provides excellent heat dissipation performance, effectively extending the service life of the device;

[0039] The bottom plate 2 is provided with a sliding groove 4 of a certain depth, and there is an array of threaded holes 9 at equal distances in the middle of the sliding groove 4. The opening size of the sliding opening 10 is equal to the diameter of the threaded hole 9. The size of the focused light spot can be conveniently adjusted by sliding the position of the lens holder 3. The sliding groove 4 on the bottom plate 2 also has a built-in intelligent indication system, which is combined with the array of threaded holes 9 and the sliding opening 10, and assists the user to quickly and accurately adjust the position of the lens holder 3 through digital display, further improving the adjustment efficiency and accuracy.

[0040] According to the high-power semiconductor laser system used, refer to its manual to determine the fiber core diameter and beam quality M of its output fiber. 2 The size of the optical fiber core diameter is 100um, and the beam quality is M 2Taking a semiconductor laser with a size of 70.5 as an example, if the spot needs to be focused to 560um, through open source software such as reZonator, it can be calculated that the focal length of the first lens is 35mm, the focal length of the second lens is 100mm, the distance between the first lens and the semiconductor laser coupling head is 35mm, the distance between the second lens and the semiconductor laser coupling head is 135mm, and the distance between the focus point and the semiconductor laser coupling head is 385mm. Through digital display to assist users to quickly place the lens holder to the corresponding position, through the precision slide rail and the sliding groove 4 on the bottom plate 2, combined with the threaded hole 9 array for fine positioning, the flexible adjustment of the focus spot size can be achieved to meet the needs of different application scenarios.

[0041] Those skilled in the art will easily understand that the above descriptions are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A tunable focusing device for a high-power semiconductor laser, characterized in that: It comprises a semiconductor laser coupling head (1), a base plate (2), a lens holder (3), an optical fiber fixing head (5) and a lens (13); The bottom plate (2) is provided with a sliding groove (4) adapted to the lens seat (3), and a threaded hole (9) is provided in the sliding groove; The bottom of the lens holder (3) is provided with a sliding opening (10) for fixing with the sliding groove (4); the top is provided with a step (11) for increasing the fixing stability; The semiconductor laser coupling head (1) is provided with fixing grooves (12) on both sides, and the semiconductor laser coupling head (1) is fixed to the bottom plate by screws, and the output optical fiber of the semiconductor laser is connected to the optical fiber fixing head (5) to realize laser input; The semiconductor laser coupling head (1) is provided with a water inlet (6) and a water outlet (7) with threads, which are used to connect a water pipe quick plug and access a cooling water system to dissipate heat and ensure the stability of the output light spot mode when the high-power semiconductor laser is running. The semiconductor laser coupling head (1) is also provided with a plugging thread (8) which is coupled with a screw of a corresponding aperture to prevent water from overflowing from the plugging when cooling water is introduced from the water inlet.

2. The tunable focusing device for high-power semiconductor laser according to claim 1, characterized in that: The width of the sliding groove (4) is equal to the width of the lens seat (3), and the size of the focused light spot is adjusted by sliding the position of the lens seat (3) in the sliding groove (4), and the height of the lens seat (3) ensures that the center height of the lens is consistent with the height of the output light beam of the semiconductor laser coupling head (1).

3. The tunable focusing device for high-power semiconductor laser according to claim 1, characterized in that: The lens seat (3) comprises a first lens seat and a second lens seat, and the lens (13) comprises a first lens and a second lens.

4. The tunable focusing device for high-power semiconductor laser according to claim 3, characterized in that: The lens (13) is a plano-convex lens or a plano-concave lens.

5. The tunable focusing device for high-power semiconductor laser according to claim 1, characterized in that: The plane side of the lens (13) is tightly fitted on the step (11) and fixed on the lens holder (3) via thermally conductive silicone to ensure its fixing stability and good thermal conductivity.

6. The tunable focusing device for high-power semiconductor laser according to claim 1, characterized in that: An array of threaded holes (9) with equal distances is provided in the middle of the sliding groove (4); the size of the sliding opening (10) is equal to the diameter of the threaded hole (9); the size of the focused light spot can be conveniently adjusted by sliding the position of the lens holder (3); and the height of the lens holder (3) should ensure that the center height of the lens (13) is consistent with the height of the output light beam of the semiconductor laser coupling head (1).

7. The tunable focusing device for high-power semiconductor laser according to claim 6, characterized in that: The sliding groove (4) has a built-in intelligent indication system, which is combined with the threaded hole (9) array and the sliding opening (10) to assist the user in quickly and accurately adjusting the position of the lens holder (3) through digital display.

8. The tunable focusing device for high-power semiconductor laser according to claim 7, characterized in that: The intelligent indication system integrates a remote control interface, allowing a user to remotely monitor and adjust the position of the lens holder (3) through an external device, thereby realizing intelligent control of the focus spot size.

9. A focusing method using the tunable focusing device for high-power semiconductor laser according to any one of claims 1 to 8, characterized in that: The steps include: 1) Fix the semiconductor laser coupling head on the base plate, and connect the output optical fiber of the semiconductor laser to the optical fiber fixing head; 2) Connect the water pipe to the water inlet and outlet of the semiconductor laser coupling head, and couple it with the screws of the corresponding aperture through the plugging thread to ensure that no water overflows from the plugging thread when the cooling water is introduced; 3) Determine the diameter of the focused light spot according to the core diameter of the semiconductor laser output fiber and the quality of the fiber, and then calculate the focal length of the first lens and the second lens and their positions relative to the semiconductor laser output coupling head; 4) By using an external remote device to monitor the built-in intelligent indication system, the lens mount is placed in the calculated position and fixed with screws passing through the sliding opening and the threaded holes on the base plate; 5) When the focus spot size needs to be changed, the intelligent indication system is used to monitor and repeat steps 3) and 4), thereby realizing the focus spot tunable function.

10. The focusing method of the tunable focusing device for high-power semiconductor laser according to claim 9, characterized in that: In step 3, open source software is used to calculate the focal length and position of the lens.

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