Slat laser with diamond direct cooling structure

Abstract

The invention discloses a batten laser with a diamond direct cooling structure, the upper surface and the lower surface of a batten crystal in the batten laser are respectively bonded and connected with two diamond heat sinks through a low-temperature bonding technology, and direct heat dissipation is carried out by utilizing high heat conductivity of the diamond heat sinks; pump light emitted by a pumping source in the lath laser is subjected to beam shaping through the shaping lens group and then enters the lath crystal to realize absorption pumping, so that the pumping efficiency is improved; the resonant cavity end mirror and the output coupling mirror form a resonant cavity, and laser passes through the resonant cavity to form oscillation under the action of pumping so as to realize output. The upper surface and the lower surface of the lath crystal are in bonding connection with the diamond heat sink through the low-temperature bonding technology, efficient cooling is achieved, and compared with a traditional lath laser, the problems of the thermal lens effect, crystal damage and the like can be effectively reduced, and meanwhile the overall manufacturing process is simplified.

Description

Technical Field

[0001] The invention relates to the technical field of solid lasers, and in particular to a slab laser with a diamond direct cooling structure. Background Art

[0002] The fundamental reason why traditional solid-state lasers limit high-power, high-beam-quality laser output is that the shape of the gain medium determines the existence of a relatively serious thermal effect inside it. In order to get rid of the thermal effect problem of traditional rod-shaped and block-shaped solids, many solutions have been proposed. The main configurations of solid-state lasers are rod lasers, slab lasers, disk lasers, and fiber lasers. Among them, slab lasers have a larger thermal contact area and better heat dissipation effect, and are widely used in medium and high-power lasers and laser amplifiers.

[0003] The most commonly used heat dissipation method for slab lasers is water cooling, which uses water-cooled heat sinks on the two large surfaces of the slab crystal to dissipate heat. This method increases the heat dissipation area and effectively reduces the thermal lens effect inside the crystal. Currently, among the cooling heat sinks of slab lasers, the most commonly used is a copper heat sink. First, the copper heat sink is welded to the large surface of the slab crystal, and then the high thermal conductivity of copper is used to flush water into the heat sink for cooling. The copper heat sink has a good heat dissipation effect, but during the welding process, high temperature can easily damage the laser crystal, and the commonly used indium solder can easily form a new thermal resistance, reducing the heat dissipation efficiency. In addition, the pump light can easily melt the indium, which is not conducive to the efficient output of the laser. At the same time, with the increase of laser pump power and the development of laser technology, the thermal conductivity of copper has gradually failed to meet the requirements. Summary of the invention

[0004] The purpose of the present invention is to provide a slab laser with a diamond direct cooling structure, which is bonded to the diamond heat sink on the upper and lower surfaces of the slab crystal through low-temperature bonding technology to achieve efficient cooling. Compared with traditional slab lasers, it can effectively reduce problems such as thermal lens effect and crystal damage while simplifying the overall process.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A slab laser with a diamond direct cooling structure, wherein the upper and lower surfaces of the slab crystal in the slab laser are bonded to two diamond heat sinks respectively by low temperature bonding technology, and the high thermal conductivity of the diamond heat sink is used to directly dissipate heat;

[0007] The pump light emitted by the pump source in the slab laser is beam shaped by the shaping lens group and then enters the slab crystal to realize absorption pumping, thereby improving the pumping efficiency;

[0008] The resonant cavity end mirror and the output coupling mirror form a resonant cavity. The laser oscillates through the resonant cavity under the action of pumping to achieve output.

[0009] It can be seen from the technical solution provided by the present invention that the slab laser of this structure is bonded to the diamond heat sink on the upper and lower surfaces of the slab crystal through low-temperature bonding technology to achieve efficient cooling. Compared with traditional slab lasers, it can effectively reduce problems such as thermal lens effect and crystal damage while simplifying the overall process. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0011] Figure 1 A schematic diagram of the structure of a slab laser with a diamond direct cooling structure provided by an embodiment of the present invention;

[0012] Figure 2 The schematic diagram of the structure of the slab laser with double-end pumping is shown;

[0013] Figure 3 It is a schematic diagram of the structure of the resonant cavity of a partially end-pumped slab laser with single-end pumping according to an embodiment of the present invention;

[0014] Figure 4 It is a schematic diagram of the structure of the resonant cavity of the double-end-pumped partially end-pumped slab laser according to an embodiment of the present invention;

[0015] Figure 5 It is a schematic diagram of the structure of a laser amplifier with single-ended pumping according to an embodiment of the present invention;

[0016] Figure 6 It is a schematic diagram of the structure of a laser amplifier with double-end pumping according to an embodiment of the present invention;

[0017] Figure 7 It is a schematic diagram of the structure of a partially end-pumped slab laser amplifier with single-ended pumping according to an embodiment of the present invention;

[0018] Figure 8 It is a schematic structural diagram of a partially end-pumped slab laser amplifier with double-end pumping according to an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, which does not constitute a limitation of the present invention. 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.

[0020] like Figure 1 FIG. 1 is a schematic diagram of a slab laser with a diamond direct cooling structure provided by an embodiment of the present invention. The upper and lower surfaces of the slab crystal 1 in the slab laser are respectively bonded to two diamond heat sinks ( Figure 1 2 and 3) are bonded together, and the high thermal conductivity of the diamond heat sink is used for direct heat dissipation;

[0021] The pump light 5 emitted by the pump source 4 in the slab laser is beam shaped by the shaping lens group 6 and then enters the slab crystal 1 to realize absorption pumping and improve the pumping efficiency;

[0022] The resonant cavity end mirror 7 and the output coupling mirror 8 form a resonant cavity. The laser passes through the resonant cavity to form oscillation under the action of pumping, and output is achieved to obtain output laser 9.

[0023] In a specific implementation, the pump source selects a single-ended pump or a double-ended pump according to the required power and actual conditions. Figure 1 The slab laser shown is a single-end pumped Figure 2 The figure shows the schematic diagram of the structure of the slab laser with double-end pumping. Figure 2 middle:

[0024] If double-end pumping is used, the pump light 5 emitted by the pump source 4 and the pump light 11 emitted by the pump source 10 at the opposite end are respectively shaped by the first shaping lens group 6 and the second shaping lens group 12, and then enter the slab crystal 1 to realize double-end pumping;

[0025] The resonant cavity end mirror 7 , the output coupling mirror 8 , the first reflector 13 and the second reflector 14 form a resonant cavity. The laser passes through the resonant cavity to form oscillation under the action of pumping, and output is achieved to obtain output laser 9 .

[0026] In the specific implementation, in single-ended pumping, the side of the resonant cavity end mirror 7 close to the crystal is coated with a 1064nm high-reflection film, and the other side is coated with an 808nm anti-reflection film; in double-ended pumping, the side of the first reflector 13 and the second reflector 14 close to the crystal is coated with a 1064nm high-reflection film, and the other side is coated with an 808nm anti-reflection film.

[0027] In addition, if there are requirements for the size and scalability of the laser, you can choose to use a partially end-pumped slab laser resonator, such as Figure 3 The figure shows a schematic diagram of the structure of a single-end pumped partially end-pumped slab laser resonant cavity according to an embodiment of the present invention. The resonant cavity includes two reflectors ( Figure 3 15 and 16), the slab laser resonator is end-pumped through the resonator end mirror 7, the output coupling mirror 8, the third reflector 15 and the fourth reflector 16;

[0028] The third reflector 15 is coated with an 808nm anti-reflection film on one side close to the single-ended pump and a 1064nm high-reflection film on the other side; the fourth reflector 16 is coated with a 1064nm high-reflection film on the side opposite to the third reflector 15 .

[0029] like Figure 4 The figure shows a schematic diagram of the structure of a double-end pumped partially end-pumped slab laser resonant cavity according to an embodiment of the present invention, in which a pump source 10 of the same structure is arranged at the opposite end of the pump source 4 .

[0030] The above-mentioned partial end-pumped slab laser resonator has good output laser beam quality and strong scalability, and the oscillator cavity structure can be selected according to actual needs.

[0031] In a specific implementation, the slab laser can also be used for laser amplification, such as Figure 5 The figure shows a schematic diagram of the structure of a laser amplifier with single-end pumping according to an embodiment of the present invention. A fifth reflector 18 is provided in the slab laser, and a surface of the fifth reflector 18 is coated with a corresponding laser high-reflection film;

[0032] After being reflected by the fifth reflecting mirror 18 and passing through the slab crystal 1 , the external laser light 17 is power amplified.

[0033] In single-ended pumping, the side of the fifth reflector 18 close to the crystal is coated with a 1064nm high-reflection film, and the other side is coated with an 808nm anti-reflection film.

[0034] like Figure 6 FIG. 1 is a schematic diagram of the structure of a laser amplifier with double-end pumping according to an embodiment of the present invention, which includes two reflectors ( Figure 6 18 and 19), the surfaces of the two reflectors are coated with corresponding laser high-reflection films, the pump source 4 and the pump source 10 at the opposite end perform double-end pumping on the slab crystal 1 to form a laser amplifier with double-end pumping; the external laser 17 is reflected by the fifth reflector 18 and passes through the slab crystal 1 to achieve power amplification, and then is reflected out of the light path by the sixth reflector 19.

[0035] In double-end pumping, the fifth reflector 18 and the sixth reflector 19 are coated with a 1064nm high-reflection film on one side close to the crystal, and are coated with an 808nm anti-reflection film on the other side.

[0036] In the specific implementation, Figure 7 The figure shows a schematic structural diagram of a partially end-pumped slab laser amplifier with single-end pumping according to an embodiment of the present invention. In the slab laser, a third reflector 15, a fourth reflector 16 and a slab crystal 1 constitute a partially end-pumped slab laser amplifier;

[0037] The external laser 17 enters the interior of the crystal from one end of the slab crystal 1, and after multiple reflections by the third reflector 15 and the fourth reflector 16, sufficient power amplification is achieved to obtain a high-quality beam output.

[0038] In addition, in order to increase the output energy of the laser amplifier, a double-ended pumping structure can also be selected, such as Figure 8 It is a schematic structural diagram of a partially end-pumped slab laser amplifier with double-end pumping according to an embodiment of the present invention, in which a slab crystal 1 is double-end pumped by a pump source 4 and a pump source 10 at the opposite end.

[0039] The diamond heat sink may be replaced by a sapphire or silicon carbide high thermal conductivity heat sink.

[0040] In addition, in the embodiment of the present invention, the gain medium of the slab crystal is Nd:YAG, the pump light is 808nm, and the output laser is 1064nm. In fact, the gain medium material includes but is not limited to Nd:YAG, Nd:YVO4, Yb:YAG, Tm:YAG, Ho:YAG and other gain media suitable for processing into slabs; the pump light wavelength is changed accordingly according to the gain medium.

[0041] It is worth noting that the contents not described in detail in the embodiments of the present invention belong to the prior art known to professional and technical personnel in the field.

[0042] In summary, the embodiments of the present invention can achieve efficient cooling by optimizing parameters such as the size of the slab crystal and bonding the upper and lower surfaces of the slab crystal to a diamond heat sink using low-temperature bonding technology. Compared with traditional slab lasers, the present invention does not require solder during bonding and does not generate new thermal resistance. It can fully reduce the thermal expansion and contraction phenomena of traditional high-temperature bonding, reduce crystal stress, and can simplify the overall process while effectively reducing problems such as thermal lens effect and spot dispersion.

[0043] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A slab laser with a diamond direct cooling structure, characterized in that: The upper and lower surfaces of the slab crystal in the slab laser are respectively bonded to two diamond heat sinks by low temperature bonding technology, and the high thermal conductivity of the diamond heat sink is used to directly dissipate heat; The pump light emitted by the pump source in the slab laser is beam shaped by the shaping lens group and then enters the slab crystal to realize absorption pumping, thereby improving the pumping efficiency; The resonant cavity end mirror and the output coupling mirror form a resonant cavity. The laser oscillates through the resonant cavity under the action of pumping to achieve output.

2. The slab laser with diamond direct cooling structure according to claim 1, characterized in that: The pump source selects single-end pumping or double-end pumping according to the required power and actual conditions; Wherein, if it is double-ended pumping, the pump light emitted by the pump source and the pump light emitted by the pump source at the opposite end are respectively shaped by the first shaping lens group and the second shaping lens group, and then enter the slab crystal to realize double-ended pumping; The resonant cavity end mirror, the output coupling mirror, the first reflector and the second reflector form a resonant cavity. The laser passes through the resonant cavity to form oscillation under the action of pumping, and output is achieved to obtain output laser.

3. The slab laser with diamond direct cooling structure according to claim 1, characterized in that: The resonant cavity comprises two reflectors, and the resonant cavity of the slab laser is end-pumped through the resonant cavity end mirror, the output coupling mirror, the third reflector and the fourth reflector. The third reflector is coated with an 808nm anti-reflection film on one side close to the single-ended pump and a 1064nm high-reflection film on the other side; the fourth reflector is coated with a 1064nm high-reflection film on the side opposite to the third reflector.

4. The slab laser with a diamond direct cooling structure according to claim 1, characterized in that: The slab laser can also be used for laser amplification, wherein: If it is a single-end pump structure, a fifth reflector is provided in the slab laser, and the surface of the fifth reflector is coated with a corresponding laser high-reflection film; after the external laser is reflected by the fifth reflector and passes through the slab crystal, power amplification is achieved; If it is a double-end pumping structure, two reflectors are set in the slab laser, and the surfaces of the two reflectors are coated with corresponding laser high-reflection films; the external laser is reflected by the fifth reflector and passes through the slab crystal to achieve power amplification, and then reflected out of the light path by the sixth reflector.

5. The slab laser with diamond direct cooling structure according to claim 1, characterized in that: In the slab laser, the third reflector, the fourth reflector and the slab crystal constitute a part of the end-pumped slab laser amplifier; The external laser enters the interior of the crystal from one end of the slab crystal, and after multiple reflections by the third reflector and the fourth reflector, sufficient power amplification is achieved to obtain a high-quality beam output.

6. The slab laser with a diamond direct cooling structure according to claim 2, characterized in that: In single-ended pumping, the side of the resonant cavity mirror close to the crystal is coated with a 1064nm high-reflection film, and the other side is coated with an 808nm anti-reflection film; In double-ended pumping, the first and second reflectors are coated with a 1064nm high-reflection film on one side close to the crystal, and an 808nm anti-reflection film on the other side.

7. The slab laser with a diamond direct cooling structure according to claim 1, characterized in that: The diamond heat sink can be replaced by a sapphire or silicon carbide high thermal conductivity heat sink.

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