Semiconductor side pump module and laser

Abstract

The invention provides a semiconductor side pump module and a laser, and relates to the technical field of semiconductor lasers. The semiconductor side pump module comprises a light gathering cavity, a cooling pipe is coaxially arranged in a cavity body of the light gathering cavity, a crystal bar is coaxially arranged in the cooling pipe, and the cooling pipe and the crystal bar jointly form a cooling space used for containing cooling liquid. An odd number of pumping units are uniformly distributed on the outer side of the light condensing cavity along the circumferential direction; and each pumping unit comprises a plurality of pumping sources which are uniformly arranged along the axial direction. A slit allowing pump light to enter is formed in the light gathering cavity. And fast axis shaping negative lenses in one-to-one correspondence with the pumping units are arranged on the outer side of the cooling pipe in the cavity. The semiconductor side pump module and the laser provided by the invention can effectively improve the uniformity of light spots.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor lasers, in particular to a semiconductor side pump module and a laser. Background Art

[0002] Semiconductor side-pump lasers are widely used in industrial, medical, and military applications. In this structure, the pump is placed along the axis of the laser crystal, with the pump module and crystal fixed at both ends. Pumping is performed transversely relative to the optical axis through the surface of the crystal rod, increasing the crystal's heat dissipation area and pump coupling area, facilitating high-power pump light injection.

[0003] However, the gain distribution in this structure is difficult to match well with the fundamental mode of the resonant cavity, and the pump light will pass through the coolant, glass tube and other components when reaching the crystal, which will easily cause loss and reduce the pump efficiency. At the same time, during the cooling process, there will be a temperature difference between the surface and the middle of the crystal, which will lead to a decrease in the uniformity of the light spot, resulting in the following problems: Figure 8 The strong heart phenomenon shown in the figure shows that the beam quality is severely degraded and the efficiency is low after being amplified by the side pump module. Summary of the Invention

[0004] In response to the above problems, the present application provides a semiconductor side pump module and a laser that can effectively improve the uniformity of the light spot.

[0005] The technical solution adopted by the present invention to solve the technical problem is:

[0006] A semiconductor side pump module comprises a focusing cavity, a cooling tube is coaxially arranged in the cavity of the focusing cavity, a crystal rod is coaxially arranged in the cooling tube, and the cooling tube and the crystal rod together form a cooling space for accommodating a coolant;

[0007] An odd number of pumping units are evenly distributed along the circumferential direction on the outer side of the focusing cavity, and each of the pumping units includes a plurality of pumping sources evenly arranged along the axial direction;

[0008] The focusing cavity is provided with a slit for allowing the pump light to enter;

[0009] A fast axis shaping negative lens corresponding to each of the pump units is provided in the cavity on the outside of the cooling tube.

[0010] Furthermore, the cooling pipe is provided with an inlet and an outlet, and the inlet and the outlet are respectively connected to the refrigeration device.

[0011] Furthermore, the cooling tube includes a main body, end plates are respectively provided at both ends of the main body, avoidance holes are provided on the end plates, sealing rings are provided between the side of the avoidance hole and the crystal rod, and a liquid inlet pipe and a liquid outlet pipe are respectively provided on both sides of the focusing cavity on the main body.

[0012] Furthermore, the cooling tube is made of glass.

[0013] Furthermore, the pump source adopts a bar.

[0014] Furthermore, the fast axis shaping negative lens is fixedly arranged on the side surface of the cavity of the focusing cavity in a detachable manner.

[0015] Furthermore, the material of the fast axis shaping negative lens is optical glass LaSF9.

[0016] Furthermore, after passing through the fast axis shaping negative lens, the divergence angle of the pump light is greater than or equal to 65°.

[0017] Furthermore, an outer surface of the focusing cavity is provided with arc-shaped grooves or mounting planes corresponding one-to-one to the pump units.

[0018] A laser comprises the semiconductor side pump module.

[0019] The beneficial effects of the present invention are:

[0020] The semiconductor side pump module and laser provided in this application utilize a fast-axis shaping negative lens to shape the fast-axis direction of the pump light emitted by the pump source, thereby increasing the fast-axis divergence angle. This increased fast-axis divergence angle expands the area of ​​the crystal side illuminated by the pump light, thereby improving the uniformity of the fluorescence distribution.

[0021] In addition, by increasing the fast-axis divergence angle of the pump light, high uniformity can be achieved by reducing the number of pump sources, while also reducing product costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the three-dimensional structure of a semiconductor side pump module provided in Example 1 of the present application;

[0023] Figure 2 A side view of a semiconductor side pump module provided in Example 1 of the present application;

[0024] Figure 3 for Figure 2 AA section view in;

[0025] Figure 4 This is a front view of a semiconductor side pump module provided in Example 1 of the present application;

[0026] Figure 5 for Figure 4 BB cross-sectional view in;

[0027] Figure 6 A fluorescence distribution diagram of a light spot is obtained by using a semiconductor side pump module provided in Example 1 of the present application;

[0028] Figure 7 A schematic structural diagram of a semiconductor side pump module provided in Example 2 of the present application;

[0029] Figure 8 This is the fluorescence distribution diagram of the light spot generated by a traditional semiconductor side-pump laser.

[0030] In the figure: 1, focusing cavity; 11, cavity; 12, slit; 13, arc-shaped groove; 14, mounting plane; 2, cooling tube; 21, main body; 22, end plate; 23, liquid inlet pipe; 24, liquid outlet pipe;

[0031] 3. Crystal rod;

[0032] 4. Coolant;

[0033] 5. Pump unit; 51. Pump source;

[0034] 6. Fast axis shaping negative lens. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be described in detail below in conjunction with the drawings in the embodiments of this application. The described embodiments are only part of the embodiments of this application, not all of the embodiments. All other embodiments obtained by those skilled in the art without creative work based on the embodiments of this application should fall within the scope of protection of this application.

[0036] Example 1

[0037] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 and Figure 5As shown, a semiconductor side pump module includes a focusing cavity 1, a cooling pipe 2 coaxially arranged with the cavity 11 is provided in the cavity 11 of the focusing cavity 1, and an annular cavity is formed between the cooling pipe 2 and the focusing cavity 1. A crystal rod 3 coaxially arranged with the cooling pipe 2 is provided in the cooling pipe 2, and the cooling pipe 2 and the crystal rod 3 together form an annular cooling space, and the cooling space is filled with a coolant 4. An inlet and an outlet are provided on the cooling pipe 2, and the inlet and outlet are respectively connected to a refrigeration device (not shown in the figure). Under the action of the refrigeration device, the coolant 4 enters the cooling space from the inlet and flows out from the outlet. In this process, the coolant 4 exchanges heat with the crystal rod 3, thereby taking away the heat generated by the crystal rod 3 and maintaining the crystal rod 3 within a suitable temperature range. After the coolant 4 returns to the refrigeration device, it is cooled and then returns to the cooling space through the inlet for the next heat exchange cycle. An odd number of pump units 5 are evenly distributed along the circumference of the focusing cavity 1. Each pump unit 5 includes a plurality of pump sources 51 evenly arranged along the axial direction. Each pump unit 5 includes the same number of pump sources 51, which are aligned one by one. A slit 12 is provided in the focusing cavity 1, through which pump light emitted by the pump sources 51 can enter the cavity 11 of the focusing cavity 1.

[0038] As a specific embodiment, five pump units 5 are evenly distributed along the circumference of the outer side of the focusing cavity 1 described in this embodiment, and each pump unit 5 includes seven pump sources 51. Five slits 12 are evenly distributed along the circumference on the sidewall of the focusing cavity 1, and the seven pump sources 51 in the same pump unit 5 share one slit 12.

[0039] As another embodiment, the number of slits 12 provided on the side wall of the focusing cavity 1 may be the same as the number of pump sources 51 , and they correspond one to one. The pump light emitted by the pump source 51 is incident into the cavity 11 of the focusing cavity 1 through the corresponding slits 12 .

[0040] As a specific implementation, the pump source 51 described in this embodiment adopts a bar, and the light-emitting side of the bar faces the corresponding slit 12 .

[0041] As a specific embodiment, the cooling tube 2 described in this embodiment includes a main body 21, with end plates 22 provided at both ends of the main body 21. The end plates 22 are provided with a clearance hole for evacuating the crystal rod 3, and a sealing ring is provided between the side of the clearance hole and the crystal rod 3. The main body 21 is provided with a liquid inlet pipe 23 and a liquid outlet pipe 24 on both sides of the focusing cavity 1, which are connected to the internal space of the main body 21. The open end of the liquid inlet pipe 23 is the inlet, and the open end of the liquid outlet pipe 24 is the outlet. The main body 21, end plates 22, liquid inlet pipe 23, and liquid outlet pipe 24 are an integrated structure made of glass.

[0042] like Figure 2 、 Figure 3 and Figure 5 As shown, a fast-axis shaping negative lens 6 corresponding to the pump unit 5 is provided in the annular cavity. When the pump light emitted by the pump source 51 passes through the slit 12, it first passes through the fast-axis shaping negative lens 6 to increase the divergence angle, then passes through the cooling tube 2 and the coolant 4 in sequence, and finally reaches the side of the crystal rod 3 and is absorbed by the crystal rod 3. The light that is not absorbed is reflected multiple times in the cavity 11 of the focusing cavity 1 until it is absorbed by the crystal rod 3. The side of the cavity 11 is a reflecting surface.

[0043] Furthermore, the fast axis shaping negative lens 6 is fixedly arranged on the side surface of the cavity 11 of the focusing cavity 1 in a detachable manner.

[0044] In this way, the curvature of the fast-axis shaping negative lens 6 can be adjusted according to the divergence angles of different pump sources 51 , crystal rods 3 of different sizes, and side pump modules of different dimensions, with a wide range of adaptability and applicability.

[0045] As a specific implementation, the fast axis shaping negative lens 6 described in this embodiment is fixedly connected to the side surface of the cavity 11 by bonding.

[0046] like Figure 6 As shown, by adding a fast-axis shaping negative lens 6 between the pump source 51 and the crystal rod 3, and setting the thickness and curvature radius of the lens according to the light transmission theory, the fast-axis divergence angle is increased, and the uniformity of the light spot obtained by ray tracing reaches 90%, which can effectively improve the uniformity of the light spot.

[0047] The divergence angle of the pump light, the pumping distance from the pump light to the crystal rod 3, the diameter and refractive index of the cooling tube 2, the thickness, flow rate and refractive index of the coolant 4, and the size and doping concentration of the crystal rod 3 all affect the fluorescence distribution. Optimizing any one parameter of the pumping distance, cooling tube 2, and coolant 4 requires modifying the overall product structure design, which is costly. The present application improves the uniformity of fluorescence distribution by increasing the divergence angle. This only requires adding a fast-axis shaping negative lens 6, without adjusting other structural elements, resulting in a low optimization cost.

[0048] As a specific implementation, the material of the fast axis shaping negative lens 6 in this embodiment is optical glass LaSF9, which has a high refractive index of 1.88. It can achieve a shorter focal length or a larger spot diameter through the high refractive index, which is very helpful in increasing the divergence angle.

[0049] Furthermore, after passing through the fast-axis shaping negative lens 6 , the divergence angle of the pump light is greater than or equal to 65°.

[0050] Furthermore, in order to facilitate installation and coordination with other parts, an arc-shaped groove 13 corresponding to each of the pump units 5 is provided on the outer surface of the focusing cavity 1 , and the slit 12 is provided in the arc-shaped groove 13 .

[0051] An embodiment of the present application further provides a laser, which includes the semiconductor side pump module described above.

[0052] Example 2

[0053] like Figure 7 As shown, a mounting plane 14 corresponding to each of the pump units 5 is provided on the outer surface of the focusing cavity 1, and the slit 12 is provided on the mounting plane 14. The rest of the structure is the same as that of the first embodiment.

[0054] Other embodiments obtained by those skilled in the art by combining, splitting, reorganizing, etc. the embodiments provided in this application do not exceed the scope of protection of this application.

[0055] The above specific implementation methods provide a detailed description of the purpose, technical solutions and beneficial effects of the embodiments of the present application. The above is only a specific implementation method of the embodiments of the present application and is not intended to limit the scope of protection of the embodiments of the present application. That is, any modifications, equivalent replacements, improvements, etc. made on the basis of the embodiments of the present application should be included in the scope of protection of the embodiments of the present application.

Claims

1. A semiconductor side pump module, characterized in that: The invention comprises a focusing cavity (1), wherein a cooling tube (2) is coaxially arranged in a cavity body (11) of the focusing cavity (1), a crystal rod (3) is coaxially arranged in the cooling tube (2), and the cooling tube (2) and the crystal rod (3) together form a cooling space for accommodating a cooling liquid (4); An odd number of pumping units (5) are evenly distributed along the circumferential direction on the outer side of the focusing cavity (1), and each of the pumping units (5) includes a plurality of pumping sources (51) evenly arranged along the axial direction; The focusing cavity (1) is provided with a slit (12) for allowing pump light to enter; A fast axis shaping negative lens (6) corresponding one-to-one to the pump unit (5) is provided on the outside of the cooling tube (2) in the cavity (11).

2. A semiconductor side pump module according to claim 1, characterized in that: The cooling pipe (2) is provided with an inlet and an outlet, and the inlet and the outlet are respectively connected to the refrigeration device.

3. A semiconductor side pump module according to claim 2, characterized in that: The cooling tube (2) comprises a main body (21), end plates (22) are respectively provided at both ends of the main body (21), avoidance holes are provided on the end plates (22), a sealing ring is provided between the side of the avoidance hole and the crystal rod (3), and a liquid inlet pipe (23) and a liquid outlet pipe (24) are respectively provided on both sides of the focusing cavity (1) on the main body (21).

4. A semiconductor side pump module according to claim 1, characterized in that: The cooling tube (2) is made of glass.

5. The semiconductor side pump module according to claim 1, characterized in that: The pump source (51) adopts a bar.

6. The semiconductor side pump module according to claim 1, characterized in that: The fast axis shaping negative lens (6) is fixedly arranged on the side surface of the cavity (11) of the focusing cavity (1) in a detachable manner.

7. The semiconductor side pump module according to claim 1, characterized in that: The material of the fast axis shaping negative lens (6) is optical glass LaSF9.

8. The semiconductor side pump module according to claim 1, characterized in that: After passing through the fast axis shaping negative lens (6), the divergence angle of the pump light is greater than or equal to 65 degrees.

9. The semiconductor side pump module according to claim 1, characterized in that: The outer surface of the focusing cavity (1) is provided with arc-shaped grooves (13) or mounting planes (14) corresponding one-to-one to the pump units (5).

10. A laser, characterized in that: Comprising the semiconductor side pump module according to any one of claims 1-9.

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