Radiating device applied to disc laser and laser module

Abstract

The utility model provides a heat radiation device used for a laser and a laser module comprising the heat radiation device, in one embodiment, the heat radiation device comprises a laser gain medium having a first surface and a second surface; the antireflection film is arranged on the first surface of the laser crystal; the reflecting film is arranged on the second surface of the laser crystal; and the heat sink is used for supporting and fixing the laser gain medium and absorbing heat generated by the laser gain medium, and the heat sink is made of single crystal silicon carbide. The heat dissipation device provided by the utility model is low in processing cost, and facilitates the popularization and application of the disc laser.

Description

Technical Field

[0001] This utility model relates generally to the field of laser technology, and in particular to a heat dissipation device and laser module applicable to disk lasers. Background Technology

[0002] Laser technology has been widely applied in many fields such as communications, medicine, and materials processing. Based on their operating mode, lasers can be divided into continuous lasers and pulsed lasers. Among them, pulsed lasers, due to their high power and high precision, have broad application prospects in circuit manufacturing, radar detection, and fiber optic communications. Disk lasers play an important role in the generation of high-power, high-energy ultrashort pulse lasers because they can significantly reduce the thermal effects in the laser gain medium.

[0003] During operation, the gain medium of a disk laser will generate heat. If it is not dissipated in time, it will affect the working efficiency and cause deformation or damage to the device. Therefore, the heat dissipation system in the disk laser module system is a key device for reducing the thermal effect of the laser gain medium. Providing heat dissipation in a simple and cost-controllable way is the goal pursued by the industry. Utility Model Content

[0004] To address the aforementioned problems, this utility model is proposed. An embodiment of this utility model provides a heat dissipation device for disk lasers, which can achieve efficient heat dissipation of the laser gain medium of the disk laser.

[0005] According to an exemplary embodiment, a heat dissipation device applicable to a disk laser is provided, characterized in that it comprises: a laser gain medium having a first surface and a second surface; an antireflective film disposed on the first surface of the laser crystal; a reflective film disposed on the second surface of the laser crystal; and a heat sink for supporting and fixing the laser gain medium and absorbing the heat generated by the laser gain medium, the heat sink being made of single-crystal silicon carbide.

[0006] In some embodiments, the surface area of ​​the heat sink is larger than the surface area of ​​the laser gain medium.

[0007] In some embodiments, the heat dissipation device further includes a bonding layer disposed between the reflective film and the heat sink for fixing the laser gain medium onto the heat sink.

[0008] In some embodiments, the laser gain medium is a disk-type laser crystal.

[0009] In some embodiments, the laser crystal typically comprises Yb:YAG, Yb:Lu2O3, or Yb:LuAG.

[0010] In some embodiments, the single-crystal silicon carbide is cubic single-crystal silicon carbide.

[0011] In some embodiments, the bonding layer is composed of indium tin solder.

[0012] In some embodiments, the heat dissipation device further includes a water-cooling unit that is in contact with the heat sink and is used to dissipate heat from the heat sink.

[0013] In some embodiments, the water-cooling unit includes a water-cooling inlet, a water-cooling cavity, and a water-cooling outlet. The water-cooling inlet and the water-cooling outlet are in fluid communication with the water-cooling cavity, and the water-cooling inlet is directly opposite the portion of the water-cooling unit that is in contact with the heat sink.

[0014] According to an exemplary embodiment, a disk-type laser module is also provided, characterized in that it includes: a pump source for outputting pump light; the aforementioned heat dissipation device, wherein the laser gain medium receives the pump light and generates laser light; and a laser output mirror disposed on the output path of the laser light for outputting laser light.

[0015] Based on some implementation methods, the heat dissipation device of this utility model can efficiently dissipate heat from the laser gain medium in the disk laser. Compared with the heat dissipation structure materials and processing costs of the prior art, it is more conducive to the market promotion of disk laser modules.

[0016] The above and other features and advantages of this invention will become apparent from the following description of exemplary embodiments taken in conjunction with the accompanying drawings. It should be understood that the exemplary embodiments may not necessarily achieve all of these advantages. Therefore, this invention may be embodied or practiced in a manner that achieves or optimizes one or more advantages as taught herein, without necessarily achieving other advantages as taught or suggested herein. Attached Figure Description

[0017] Figure 1 A schematic diagram of the overall structure of a disk-type laser system according to an embodiment of the present invention is shown.

[0018] Figure 2 A schematic diagram of a heat dissipation device according to an embodiment of the present invention is shown.

[0019] The names of the corresponding components indicated by the reference numerals in the figure are as follows:

[0020] 1- Output laser, 2- Laser output mirror, 3- Pump beam, 4- Disk laser crystal, 5- Heat sink, 6- Water cooling unit, 7- Cooling water, 8- Antireflective coating, 9- Reflective coating, 10- Bonding layer. Detailed Implementation

[0021] Exemplary embodiments of the present invention are described below with reference to the accompanying drawings. In the drawings, the same reference numerals generally represent the same parts. It should be understood that the dimensions and sizes of the parts shown in the drawings are not necessarily drawn to scale and may differ from those shown herein for implementation. Furthermore, some embodiments may combine any suitable combination of features from two or more of the drawings.

[0022] Figure 1 A schematic diagram of the overall structure of a disk-type laser system according to an embodiment of the present invention is shown. Figure 1 As shown, a disk-type laser module may include a pump source, a heat dissipation device, and a laser output module. As described in detail below, the laser gain medium and the heat dissipation components are integrated together, and are collectively referred to as the heat dissipation device or heat dissipation module in this document.

[0023] A pump source (not shown) is used to output pump light pulses. In one embodiment, a pulsed semiconductor laser or the like can be selected for pumping. The wavelength of the pump light generated by the pump source is within the absorption spectrum range of the laser gain medium 4, for example, 800-1000 nm. After passing through a total reflection mirror, a pump beam 3 is formed and obliquely incident on the laser gain medium 4. The laser gain medium 4 receives the pump light and can generate laser 1. An output mirror 2, such as a parabolic mirror, can be provided in the output path of laser 1. Figure 1 As shown, the output mirror 2 and the laser gain medium 4 are arranged to each other. The surface opposite to the laser gain medium 4 is a parabolic surface (coated with a semi-transparent and semi-reflective film), and the optical axis is perpendicular to the laser gain medium 4. Thus, the output mirror 2 and the laser gain medium 4 form a resonant cavity. The laser generated after fully extracting energy is output through the output mirror 2.

[0024] See Figure 2 The diagram illustrates the structural composition of a heat dissipation device according to an embodiment of the present invention. Figure 2 As shown, the heat dissipation device mainly includes or integrates the following components: laser gain medium 4, heat sink 5, antireflective coating layer 8, and reflective coating layer 9.

[0025] The laser gain medium 4 is used to absorb pump light and provide gain to generate stimulated emission light. In one example, as the gain medium for laser amplification, the laser gain medium 4 can be a disk laser crystal. Its material can be a single-doped (e.g., Yb, Nd, etc.) laser crystal or a composite laser crystal, including but not limited to one or more of the following materials: yttrium aluminum garnet (Yb:YAG), yttrium lutetium oxide (Yb:Lu2O3), or yttrium lutetium aluminum garnet (Yb:LuAG).

[0026] In one embodiment, the laser gain medium 4 may have a disk shape, and the appropriate diameter can be determined according to the output laser power performance, for example, 5-16 mm. The thickness of the laser crystal may be, for example, 0.2-1 mm, preferably less than 0.5 mm. The thin crystal has better axial heat dissipation capability, which is beneficial to stable operation.

[0027] The laser gain medium 4 may have an upper surface and a lower surface in the thickness direction, which may also be referred to as the first surface and the second surface in this paper. (Refer to...) Figure 1 An antireflection coating 8 and a reflective coating 9 are respectively disposed on the first and second surfaces, for example, deposited on both sides of the laser gain medium 4. Adapted to the disk shape of the laser gain medium 4, the antireflection coating 8 and the reflective coating 9 are also circular. The antireflection coating 8 (e.g., a silicon nitride layer) transmits pump light and oscillation light (preferably with a transmittance greater than 99.5%), reducing transmission loss at the crystal incident surface; the reflective coating 9 (e.g., a high-reflectivity layer such as a gold plating layer) reflects pump light and oscillation light (preferably with a reflectance greater than 99.5%), thereby allowing the laser crystal to operate as a mirror in the resonant cavity. In one embodiment, the position of the parabolic mirror 2 relative to the laser gain medium 4, serving as the other end of the resonant cavity, can be adjusted to accommodate the size of the laser crystal and generate laser light, which is then transmitted and output through the parabolic mirror 2.

[0028] The input pump beam 3 generates a significant amount of waste heat when loaded onto the disk-type gain medium 4. To eliminate its adverse effects on the optical components, heat dissipation is necessary. For example... Figure 2 As shown, the heat dissipation device includes a heat sink 5, which can be used to support and fix the laser gain medium 4 and absorb the heat generated by the laser gain medium during operation.

[0029] In one embodiment, the heat sink 5 can be integrally connected to the laser gain medium 4 via a bonding layer 10. As shown in the figure, the bonding layer 10 is disposed between the reflective film 9 and the heat sink 5, and is used to fix the laser gain medium 4 onto the heat sink 5. The bonding layer 10 is made of a material with good thermal conductivity, so that heat on the laser gain medium 4 can be quickly conducted to the heat sink 5. For example, the material of the bonding layer 10 is preferably indium tin solder, so that the two interfaces of the heat sink 5 and the reflective film 9 can make optical contact. It is understood that thermally conductive adhesives, silver paste, etc. can also be used for bonding and fixing.

[0030] In one embodiment, the heat sink 5 is also disc-shaped, with a surface area larger than that of the laser gain medium 4, to more efficiently conduct away the heat generated by the laser gain medium 4. Specifically, the diameter of the heat sink 5 can be larger than the diameter of the laser gain medium 4, for example, greater than 12 mm, preferably greater than 15 mm; the thickness of the heat sink 5 is also greater than the thickness of the laser gain medium 4, for example, 0.5-2 mm.

[0031] Besides size, the choice of material for heat sink 5 is also a crucial factor affecting its heat dissipation performance. Diamond, due to its high thermal conductivity (1800-2000 W / (m·K)), high hardness (Mohs hardness of 10), and chemical stability, is currently widely used in the manufacture of disc-type heat sink devices. However, diamond is expensive and difficult to process, thus hindering the market promotion of disc-type laser modules.

[0032] Therefore, in this embodiment, the heat sink 5 can be formed of single-crystal silicon carbide (SiC), such as cubic single-crystal silicon carbide (3C-SiC). This material has a thermal conductivity of 300-490 W / (m·K) and a Mohs hardness of 9.5. Its thermal conductivity and hardness are second only to diamond, and it is also chemically stable with a small coefficient of thermal expansion. Therefore, it can be used as a material alternative to diamond for efficient heat exchange of crystals in disk lasers. In addition, the cost of obtaining single-crystal silicon carbide is lower than that of diamond. It can be prepared by conventional methods such as physical vapor deposition, chemical vapor deposition, and spraying, and can be installed on the water-cooling device described later by pressing and other methods. Therefore, it is beneficial to reduce the processing cost of disk laser modules and promote the marketization of disk laser modules.

[0033] return Figure 1 To further improve the heat dissipation effect on the laser gain medium 4 and promptly conduct the heat absorbed by the heat sink 5 away, in one embodiment, the heat dissipation device may further include a water-cooling unit 6, which contacts the heat sink 5 and is used to dissipate heat from the heat sink 5. For example, the main body of the water-cooling unit 6 is made of a metal with good thermal conductivity, such as copper or aluminum, and is in the shape of a shell. The upper part of the shell is flat to ensure good contact with the heat sink 5, and a cavity is formed inside the shell for the flow of cooling medium to dissipate heat. The upper shell may also have sharp corners to enhance heat dissipation performance. In addition, several fins (not shown) may be formed on the outside of the shell to improve the overall heat dissipation effect of the system.

[0034] In one embodiment, the water-cooling unit 6 includes a water-cooling inlet, a water-cooling cavity, and a water-cooling outlet (not shown). The water-cooling inlet and outlet are in fluid communication with the water-cooling cavity, and the water-cooling inlet is directly opposite the portion of the water-cooling unit that contacts the heat sink. (Refer to...) Figure 1 Water flow 7 flows into the water-cooling cavity from the outside. The direction of the water flow 7 at the water-cooling inlet is perpendicular to the extension direction of the contact shell supporting the heat sink 5 of the water-cooling unit 6, so that it can exchange heat with the heat sink 5 as soon as possible and achieve efficient heat dissipation. Overall, the waste heat generated by the pump beam 3 loaded onto the laser crystal 4 passes through the highly thermally conductive heat sink 5 and the shell 6, and is finally carried away by the low-temperature water flow 7.

[0035] Reference above Figure 1-2The present invention describes a heat dissipation device and an exemplary structure and composition of a disk-type laser module including the present invention. By using, for example, cubic single-crystal silicon carbide to fabricate the heat sink component of the disk-type laser module and supplementing it with a water cooling device, a high-efficiency heat dissipation effect can be achieved at a reduced cost, which helps to reduce the processing cost of the disk-type laser module and promote its marketization.

[0036] It should be understood that although terms such as "first" or "second" may be used herein to describe different parts or features, these parts or features are not limited to these terms. The use of these terms distinguishes only one part from another part, without emphasizing order, positional relationship, etc. For example, without departing from the scope of this disclosure, the first part may be referred to as the second part; and the second part may also be referred to as the first part. That is to say, modifiers without quantifiers, such as "first" and "second," are interchangeable.

[0037] In this text, words such as “including,” “contains,” and “has” are open-ended terms meaning “including but not limited to,” and are used interchangeably. The words “or” and “and” as used herein refer to the words “and / or” and are used interchangeably unless the context explicitly indicates otherwise. The word “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably.

[0038] The various embodiments of this utility model have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many combinations, modifications, and alterations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. Therefore, the scope of protection of this utility model should be determined by the scope of the claims.

Claims

1. A heat dissipation device for a disk laser, characterized in that... include: A laser gain medium having a first surface and a second surface; An antireflective coating is disposed on a first surface of the laser gain medium; A reflective film disposed on the second surface of the laser gain medium; and A heat sink, which is used to support and fix the laser gain medium and absorb the heat generated by the laser gain medium, is made of single-crystal silicon carbide.

2. The heat dissipation device as described in claim 1, wherein, The surface area of ​​the heat sink is greater than the surface area of ​​the laser gain medium.

3. The heat dissipation device as described in claim 1, wherein, The heat dissipation device also includes: A bonding layer, disposed between the reflective film and the heat sink, is used to fix the laser gain medium onto the heat sink.

4. The heat dissipation device as described in claim 1, wherein, The laser gain medium is a disk-type laser crystal.

5. The heat dissipation device as described in claim 4, wherein, The laser crystal includes Yb:YAG, Yb:Lu2O3, or Yb:LuAG.

6. The heat dissipation device as claimed in claim 1, wherein, The single-crystal silicon carbide is a cubic single-crystal silicon carbide.

7. The heat dissipation device as described in claim 3, wherein, The bonding layer is composed of indium tin solder.

8. The heat dissipation device as described in any one of claims 1-7, wherein, The heat dissipation device also includes: A water-cooling unit, which is in contact with the heat sink, is used to dissipate heat from the heat sink.

9. The heat dissipation device as claimed in claim 8, wherein, The water-cooling unit includes a water-cooling inlet, a water-cooling cavity, and a water-cooling outlet. The water-cooling inlet and the water-cooling outlet are in fluid communication with the water-cooling cavity. The water-cooling inlet is directly opposite the part of the water-cooling unit that is in contact with the heat sink.

10. A disk-type laser module, characterized in that... include: Pump source, used to output pump light; The heat dissipation device according to claim 1, wherein, The laser gain medium receives the pump light and generates laser light; and A laser output mirror is positioned on the output path of the laser and is used to output the laser.

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