Solid laser and temperature control device for crystal of solid laser

Abstract

The invention provides a solid laser and a temperature control device for a crystal of the solid laser. The temperature control device comprises a first heat sink assembly, a thermoelectric refrigeration part, a second heat sink assembly and a clamping assembly, the first heat sink assembly and the second heat sink assembly are oppositely arranged at an interval; the thermoelectric refrigeration part is clamped between the first heat sink assembly and the second heat sink assembly, the cold end of the thermoelectric refrigeration part faces the first heat sink assembly, and the hot end of the thermoelectric refrigeration part faces the second heat sink assembly; the clamping assembly is arranged on the side, away from the first heat sink assembly, of the second heat sink assembly and used for clamping the solid laser crystal. The thermoelectric refrigeration part is arranged between the first heat sink assembly and the second heat sink assembly, so that the temperature of the laser crystal suitable for working at high temperature can be continuously and stably maintained within a relatively low temperature fluctuation range, the crystal generates heat during working, positive feedback is carried out on the heating sheet by temperature rise, the heat conduction efficiency is higher, the temperature control effect is better, and the service life of the laser crystal is prolonged. And heat is uniformly distributed on the crystal, so that a thermal lens effect is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of solid lasers, and in particular to a solid laser and a temperature control device for a crystal thereof. Background Art

[0002] The laser crystal in a solid-state laser is the core component of laser generation. During the pumping process, the crystal excites electrons from low energy levels to high energy levels by absorbing external light sources (such as light emitted by a laser diode), and then generates lasers through stimulated radiation. However, the absorption of pump light by the crystal is not completely converted into laser energy. For all-solid-state lasers, when the laser diode pumps the gain crystal, a large amount of uneven heat will be generated inside the crystal due to the quantum loss from pump light to laser, the radiationless transition of the gain crystal from high energy level to low energy level, and lattice oscillation. If the heat is not dissipated in time, the accumulation of heat will cause the crystal temperature to rise, causing effects such as thermal lensing and thermally induced birefringence, which will directly affect the output characteristics and beam quality of the laser. The increase in temperature may also cause thermal expansion of the crystal, further causing mechanical stress, and in some cases may cause crystal damage or cracks. In order to avoid the influence of the output caused by the increase in crystal temperature during the pumping process, a heat sink with good heat dissipation effect needs to fit closely with the crystal, quickly dissipate the excess heat inside the crystal, maintain a constant temperature of the crystal, and thus ensure the stability of the laser output.

[0003] Currently, thermal management of crystals usually relies on traditional heat sink designs, such as copper or aluminum heat sinks with air or water cooling systems. These systems transfer heat from the crystal to the environment through a thermally conductive medium. Although existing heat sinks can control temperature to a certain extent, they are generally unable to effectively manage heat under high-power pumping, especially in continuous or high-repetition-rate laser applications. In addition, the temperature control of existing heat sinks is not precise enough to continuously and stably maintain the crystal within a lower temperature fluctuation range, which easily leads to heat accumulation and increases the impact of thermal lensing. The efficiency of these thermal management systems is limited by the thermal conductivity of the material and the design of the cooling system.

[0004] The contact and fit between the crystal and the heat sink determines whether the crystal temperature can be maintained in a stable atmosphere through the heat sink. The traditional contact method is to place the crystal in the clamping groove and use another small heat sink block to clamp the crystal through screws to make it fit with the heat sink. The small heat sink block acts directly on the entire crystal, and the clamping force of each surface of the crystal cannot be adjusted. Due to the existence of processing errors between the heat sink and the crystal, when the screws are fixed, there is a certain gap between the contact between the crystal and the heat sink. If the gap is removed by tightening the screws, it is bound to generate a supporting stress, causing the crystal to deform, thereby reducing the pump conversion efficiency, affecting the output laser characteristics, and even causing crystal damage or cracks. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art, and proposes a solid-state laser and a temperature control device for its crystal.

[0006] In a first aspect, the present invention provides a temperature control device for a solid laser crystal, the temperature control device comprising: a first heat sink component, a thermoelectric cooling element, a second heat sink component, and a clamping component;

[0007] The first heat sink component and the second heat sink component are arranged relatively spaced apart;

[0008] The thermoelectric cooling element is sandwiched between the first heat sink component and the second heat sink component, the cold end of the thermoelectric cooling element faces the first heat sink component, and the hot end of the thermoelectric cooling element faces the second heat sink component;

[0009] The clamping assembly is arranged on a side of the second heat sink assembly facing away from the first heat sink assembly, and the clamping assembly is used for clamping a solid laser crystal.

[0010] In some possible embodiments, a placement groove is provided on a side of the first heat sink component facing the second heat sink component, and the thermoelectric cooling element is placed in the placement groove.

[0011] In some possible embodiments, a waist-shaped hole penetrating through the thickness of the first heat sink component is disposed in an edge region of the first heat sink component.

[0012] In some possible embodiments, the thermoelectric cooling element is in contact with the first heat sink component and the second heat sink component respectively through thermal conductive silicone grease.

[0013] In some possible embodiments, the second heat sink assembly includes a heat sink main body and a placement member;

[0014] The placement member is arranged on a side of the heat sink main body away from the first heat sink assembly, and a crystal placement groove is arranged on a first surface of the placement member away from the heat sink main body;

[0015] The clamping assembly is connected to the first surface of the placement member to fix the crystal in the crystal placement groove.

[0016] In some possible embodiments, the first surface of the placement member is an inclined surface, and the clamping assembly includes a first clamping block and a second clamping block adapted to the first surface;

[0017] The first clamping block and the second clamping block are respectively arranged on both sides of the crystal placement groove, the first clamping block is fixed to the side of the first surface facing the heat sink main body, and the second clamping block is fixed to the side of the first surface away from the heat sink main body.

[0018] In some possible embodiments, the angle between the first surface and the horizontal plane ranges from 30° to 45°.

[0019] In some possible embodiments, the first surface is provided with a first mounting hole and a second mounting hole;

[0020] The first clamping block is provided with a first waist-shaped countersunk hole corresponding to the first mounting hole, so that the first clamping block is fixed to the first surface by a fastener penetrating through the first waist-shaped countersunk hole and the first mounting hole;

[0021] The second clamping block is provided with a second waist-shaped countersunk hole corresponding to the second mounting hole, so that the second clamping block can be fixed to the first surface by a fastener penetrating through the second waist-shaped countersunk hole and the second mounting hole.

[0022] In some possible embodiments, a side edge of the first clamping block facing the heat sink main body is provided with a chamfer.

[0023] In some possible embodiments, the chamfer size of the first clamping block ranges from 0.5 mm to 1.5 mm.

[0024] In a second aspect, an embodiment of the present invention provides a solid-state laser, comprising the temperature control device described above.

[0025] The beneficial effects of the present invention are:

[0026] The solid-state laser and the temperature control device for its crystal in the embodiment of the present invention can continuously and stably maintain the temperature of the laser crystal suitable for working at high temperature (40-120°C) within a relatively low temperature fluctuation range by arranging a thermoelectric cooling element between the first heat sink component and the second heat sink component. The crystal generates heat when working, and the temperature increase provides positive feedback to the heating plate. Different from the common negative feedback temperature control device, the temperature control device in the embodiment of the present invention has higher thermal conductivity efficiency and better temperature control effect. The heat is evenly distributed on the crystal, avoiding the generation of thermal lens effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is one of the structural schematic diagrams of the temperature control device of the solid laser crystal according to an embodiment of the present invention;

[0028] Figure 2 This is a second structural schematic diagram of the temperature control device for a solid laser crystal according to an embodiment of the present invention;

[0029] Figure 3 An exploded view of a temperature control device for a solid-state laser crystal according to an embodiment of the present invention;

[0030] Figure 4 for Figure 1 A front view of a temperature control device for a solid-state laser crystal as shown in ;

[0031] Figure 5 It is a schematic structural diagram of a first heat sink component in a solid laser crystal according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] Figure 1 FIG. 1 is a schematic diagram of a temperature control device for a solid-state laser crystal according to an embodiment of the present invention. Figure 2 This is a second structural schematic diagram of the temperature control device of the solid laser crystal according to an embodiment of the present invention. Figure 3 is an exploded view of a temperature control device for a solid laser crystal according to an embodiment of the present invention, Figure 4 for Figure 1 The front view of the temperature control device of the solid-state laser crystal shown in, Figure 5 It is a schematic structural diagram of a first heat sink component in a solid laser crystal according to an embodiment of the present invention.

[0036] like Figures 1 to 5As shown, an embodiment of the present invention relates to a temperature control device 100 for a solid laser crystal. The temperature control device 100 includes: a first heat sink component 110 , a thermoelectric cooling element 120 , a second heat sink component 130 and a clamping component 140 .

[0037] Specifically, Figures 1 to 3 As shown, the first heat sink assembly 110 and the second heat sink assembly 130 are arranged relatively spaced apart, for example, Figure 1 As shown, the first heat sink assembly 110 can be arranged at the bottom of the temperature control device 100, and the second heat sink assembly 130 can be arranged at a relatively spaced interval at the top of the temperature control device 100. Of course, the positions of the two can also be interchanged, and this embodiment does not limit this.

[0038] Continue to refer Figure 1 , Figure 2 and Figure 3 The thermoelectric cooling element 120 is sandwiched between the first heat sink component 110 and the second heat sink component 130, the cold end of the thermoelectric cooling element 120 faces the first heat sink component 110, and the hot end of the thermoelectric cooling element 120 faces the second heat sink component 130. That is, Figure 1 As shown, the thermoelectric cooling element 120 is located between the first heat sink assembly 110 and the second heat sink assembly 130 , and the cold end of the thermoelectric cooling element 120 is located below and in contact with the first heat sink assembly 110 , and the hot end of the thermoelectric cooling element 120 is located above and in contact with the second heat sink assembly 130 .

[0039] Next reference Figure 1 , Figure 2 and Figure 3 The clamping assembly 140 is disposed on a side of the second heat sink assembly 130 away from the first heat sink assembly 110, and the clamping assembly 140 is used to clamp the solid laser crystal 200. In other words, Figure 1 As shown, the clamping assembly 140 is disposed above the second heat sink assembly 130 and clamps and fixes the crystal 200 .

[0040] Specifically, when the temperature control device 100 of this embodiment is used to control the temperature of the crystal 200 in the solid laser, the clamping assembly 140 is used to clamp and fix the crystal 200 to the second heat sink assembly 130. Since the hot end of the thermoelectric cooling element 120 is in contact with the second heat sink assembly 130, the heat generated by the thermoelectric cooling element 120 can be transferred to the crystal 200 through the second heat sink assembly 130, thereby achieving temperature control of the crystal 200. The crystal 200 generates heat during operation, and the temperature rise provides positive feedback to the thermoelectric cooling element 120.

[0041] The temperature control device of the solid laser crystal of this embodiment can continuously and stably maintain the temperature of the laser crystal suitable for working at high temperature (40-120°C) within a relatively low temperature fluctuation range by arranging a thermoelectric cooling element between the first heat sink component and the second heat sink component. The crystal generates heat when working, and the temperature increase provides positive feedback to the heating plate. Different from the common negative feedback temperature control device, the temperature control device of the embodiment of the present invention has higher thermal conductivity efficiency and better temperature control effect. The heat is evenly distributed on the crystal, avoiding the generation of thermal lens effect.

[0042] Continue to refer Figure 1 and Figure 5 In order to facilitate the placement of the thermoelectric cooling element 120, a placement groove is provided on the side of the first heat sink component 110 facing the second heat sink component 130, and the thermoelectric cooling element 120 is placed in the placement groove. That is, Figure 1 and Figure 5 As shown, a placement groove is provided on the upper surface of the first heat sink assembly 110. Preferably, a placement groove with a depth of 0.2 mm to 0.3 mm is opened on the upper part of the first heat sink assembly 110 to effectively fix the position of the thermoelectric cooling element 120, facilitate the installation and positioning of the thermoelectric cooling element 120, and ensure stability during operation.

[0043] In order to facilitate the installation and fixing of the temperature control device 100 in the solid-state laser, Figure 5 As shown, the edge region of the first heat sink assembly 110 is provided with a waist-shaped hole 111 penetrating the thickness thereof, so that the first heat sink assembly 110 can be fixed to the solid-state laser by fasteners (such as screws, etc.) passing through the waist-shaped hole 111 .

[0044] It should be noted that there is no limitation on the number of waist-shaped holes provided in the first heat sink component. For example, four waist-shaped holes may be symmetrically provided on two opposite sides of the first heat sink component, and the present embodiment does not limit this.

[0045] Continue to refer Figure 1 In order to further improve the thermal conductivity of the temperature control device 100 and achieve better temperature control effect, so that the heat is evenly distributed on the crystal, the thermal lens effect is avoided. The thermoelectric cooling element 120 is in close contact with the first heat sink component 110 and the second heat sink component 130 through thermal grease to ensure good thermal conductivity. In some embodiments, the size of the thermoelectric cooling element 120 can be 40mm*40mm.

[0046] Please refer to Figure 1 and Figure 3, the second heat sink assembly 130 includes a heat sink main body 131 and a placement member 132. The placement member 132 is disposed on a side of the heat sink main body 131 away from the first heat sink assembly 110, and a crystal placement groove 132a is disposed on a first surface of the placement member 132 away from the heat sink main body 131. That is, Figure 3 As shown, the placement member 132 is disposed above the heat sink main body 131, and the upper surface of the placement member 132 is provided with the crystal placement groove 132a, and the clamping assembly 140 is connected to the first surface of the placement member 132 to fix the crystal 200 in the crystal placement groove 132a. In some embodiments, the corner root of the crystal placement groove 132a needs to be cleaned to prevent the edges of the crystal from being broken and damaged due to excessive pressure when being fixed.

[0047] Specifically, Figure 3 As shown, the first surface of the placement member 132 is an inclined surface, and the clamping assembly 140 includes a first clamping block 141 and a second clamping block 142 adapted to the first surface. The first clamping block 141 and the second clamping block 142 are respectively arranged on both sides of the crystal placement groove 132a, the first clamping block 141 is fixed to the side of the first surface facing the heat sink main body 131, and the second clamping block 142 is fixed to the side of the first surface facing away from the heat sink main body 131. That is, Figure 3 As shown, the first clamping block 141 is fixed below the first surface, and the second clamping block 142 is fixed above the first surface, and the crystal 200 placed in the crystal placement groove 132a is clamped and fixed by the cooperation of the first clamping block 141 and the second clamping block 142. In some embodiments, the angle between the first surface and the horizontal plane ranges from 30° to 45°, and preferably, the angle between the first surface and the horizontal plane is 45°.

[0048] The temperature control device of this embodiment is configured by setting a crystal placement groove on the inclined surface of the placement piece, and clamping and fixing the crystal placed in the crystal placement groove by means of a first clamping block and a second clamping block installed on the inclined surface. Different from the common 90° fixing angle, the temperature control device of this embodiment can make the force on the crystal more gentle and stable, and reduce the risk of damage to the crystal due to excessive force during fixing.

[0049] For example, continue to refer to Figure 3, the first surface is provided with a first mounting hole (not shown in the figure) and a second mounting hole (not shown in the figure). The first clamping block 141 is provided with a first waist-shaped countersunk hole 141a corresponding to the first mounting hole, so that the first clamping block 141 is fixed to the first surface by a fastener penetrating through the first waist-shaped countersunk hole 141a and the first mounting hole. The second clamping block 142 is provided with a second waist-shaped countersunk hole 142a corresponding to the second mounting hole, so that the second clamping block 142 is fixed to the first surface by a fastener penetrating through the second waist-shaped countersunk hole 142a and the second mounting hole.

[0050] The temperature control device of this embodiment, by setting waist-shaped countersunk holes on the first clamping block and the second clamping block, can adjust the position and strength of clamping the crystal up and down according to actual conditions when fixing the crystal. It has a high degree of freedom and can effectively eliminate the problems of loose clamping and poor contact caused by heat sinks and crystal processing errors.

[0051] For example, Figure 3 and Figure 4 As shown in FIG. 1 , the first clamping block 141 is provided with a chamfered side facing the heat sink main body 131. Figure 3 As shown, the side of the first clamping block 141 in contact with the second heat sink assembly 130 is chamfered, and the chamfer size range can be 0.5mm to 1.5mm, preferably, the chamfer size is 1mm. With this arrangement, when the crystal clamping groove is made smaller or the crystal size is enlarged due to processing errors, the crystal leaks out, and clamping in the ideal position will cause the side of the crystal to bear too much pressure, affecting the laser output characteristics or even damaging the crystal. The side chamfering provides space for the first clamping block 141 to move downward smoothly, achieving the best clamping effect.

[0052] The following describes the installation of the temperature control device according to the embodiment of the present disclosure.

[0053] like Figures 1 to 5 As shown, when assembling the temperature control device 100 of this embodiment, first fix the position of the thermoelectric cooling element 120. During installation, first wipe the two sides of the thermoelectric cooling element 120 clean with alcohol, and evenly apply a thin layer of thermal conductive silicone grease on the hot and cold surfaces of the thermoelectric cooling element 120. The surfaces of the first heat sink component 110 and the second heat sink component 130 in contact with the thermoelectric cooling element 120 should be flat and wiped clean, and thermal conductive silicone grease should also be evenly applied on the surface; during the installation process, the hot surface of the thermoelectric cooling element must be in good contact with the second heat sink component 130, and the cold surface should also be in full contact with the surface of the first heat sink component 110. After ensuring good contact, tighten with M3 cylindrical head hexagonal screws, apply force evenly on the four screws, and keep the pressure on the four corners as equal as possible. Do not apply excessive force to prevent deformation caused by uneven external pressure, which will affect the temperature control effect.

[0054] The block crystal is wrapped with a silver foil with a thickness of 0.1mm to make the crystal and the heat sink in close contact, reduce the clamping gap, and improve the heat transfer efficiency. The crystal is placed in the crystal placement groove 132a of the second heat sink assembly 130, and the second clamping block 142 is in close contact with the upper surface of the crystal and fixed through the second mounting hole (threaded hole) on the 45° side surface. The first clamping block 141 is in close contact with the side of the crystal and fixed through the mounting hole (threaded hole) on the 45° side surface. A hole with a diameter of 3mm and a depth of 4mm is processed on the non-crystalline side of the second heat sink assembly 130, and the thermistor is placed in it and fixed with glue with good thermal conductivity. The thermistor detects the crystal temperature in real time and achieves a good temperature control effect through real-time feedback.

[0055] The first heat sink assembly 110 has waist-shaped holes 111 at the four corners. When fixed, the waist-shaped holes are slightly larger than the M3 cylindrical head hexagon socket screws, so the overall temperature control device can be finely adjusted to ensure that the light path passes through the center of the front and rear surfaces of the crystal, so that the crystal position is in the best working state.

[0056] Based on the same inventive concept, an embodiment of the present invention further provides a solid laser, which includes the temperature control device described above. The specific structure of the temperature control device can refer to the relevant records above and will not be described in detail here.

[0057] The solid-state laser of the embodiment of the present invention has the temperature control device described above. By arranging a thermoelectric cooling element between the first heat sink component and the second heat sink component, the temperature of the laser crystal suitable for working at high temperature (40-120°C) can be continuously and stably maintained within a relatively low temperature fluctuation range. The crystal generates heat during operation, and the temperature increase provides positive feedback to the heating plate. Different from the common negative feedback temperature control device, the temperature control device of the embodiment of the present invention has higher thermal conductivity efficiency and better temperature control effect. The heat is evenly distributed on the crystal, avoiding the generation of thermal lens effect.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A temperature control device for a solid laser crystal, characterized in that: The temperature control device comprises: a first heat sink component, a thermoelectric cooling element, a second heat sink component and a clamping component; The first heat sink component and the second heat sink component are arranged relatively spaced apart; The thermoelectric cooling element is sandwiched between the first heat sink component and the second heat sink component, the cold end of the thermoelectric cooling element faces the first heat sink component, and the hot end of the thermoelectric cooling element faces the second heat sink component; The clamping assembly is arranged on a side of the second heat sink assembly facing away from the first heat sink assembly, and the clamping assembly is used for clamping a solid laser crystal.

2. The temperature control device according to claim 1, characterized in that: A placement groove is provided on one side of the first heat sink component facing the second heat sink component, and the thermoelectric cooling element is placed in the placement groove.

3. The temperature control device according to claim 1, characterized in that: The edge area of ​​the first heat sink component is provided with a waist-shaped hole penetrating the thickness thereof.

4. The temperature control device according to any one of claims 1 to 3, characterized in that: The thermoelectric cooling element is in contact with the first heat sink component and the second heat sink component respectively through thermal conductive silicone grease.

5. The temperature control device according to any one of claims 1 to 3, characterized in that: The second heat sink assembly includes a heat sink main body and a placement member; The placement member is arranged on a side of the heat sink main body away from the first heat sink assembly, and a crystal placement groove is arranged on a first surface of the placement member away from the heat sink main body; The clamping assembly is connected to the first surface of the placement member to fix the crystal in the crystal placement groove.

6. The temperature control device according to claim 5, characterized in that: The first surface of the placement piece is an inclined surface, and the clamping assembly includes a first clamping block and a second clamping block adapted to the first surface; The first clamping block and the second clamping block are respectively arranged on both sides of the crystal placement groove, the first clamping block is fixed to the side of the first surface facing the heat sink main body, and the second clamping block is fixed to the side of the first surface away from the heat sink main body.

7. The temperature control device according to claim 6, characterized in that: The angle between the first surface and the horizontal plane is in the range of 30° to 45°.

8. The temperature control device according to claim 6, characterized in that: The first surface is provided with a first mounting hole and a second mounting hole; The first clamping block is provided with a first waist-shaped countersunk hole corresponding to the first mounting hole, so that the first clamping block is fixed to the first surface by a fastener penetrating through the first waist-shaped countersunk hole and the first mounting hole; The second clamping block is provided with a second waist-shaped countersunk hole corresponding to the second mounting hole, so that the second clamping block can be fixed to the first surface by a fastener penetrating through the second waist-shaped countersunk hole and the second mounting hole.

9. The temperature control device according to claim 6, characterized in that: The side edge of the first clamping block facing the heat sink main body is provided with a chamfer.

10. A solid-state laser, characterized in that: The temperature control device comprises the temperature control device according to any one of claims 1 to 9.

Images