Method and structure for preventing indium metal sputtering pollution in laser resonant cavity

Abstract

The invention relates to a method and a structure for preventing indium metal sputtering pollution in a laser resonant cavity, and belongs to the technical field of high repetition frequency solid lasers. The method comprises the following steps: arranging a red glass sheet on the outer side of the end part of the laser crystal, and covering and sealing an indium metal layer for fixing the crystal. The red glass sheet has high transmissivity for 1064nm laser, can effectively prevent indium metal from volatilizing to pollute optical elements after being irradiated by the laser, and can also prevent scattered laser from being reflected back to a resonant cavity to influence the quality of light beams. The laser is simple and reliable in structure, is suitable for laser systems requiring long-term high-reliability work, such as a diode-pumped solid laser, and can significantly improve the output stability and the service life of the laser.

Description

A method and structure for preventing indium metal sputtering contamination in a laser resonant cavity Technical Field

[0001] This invention belongs to the field of high repetition rate solid-state lasers, and specifically relates to a method and structure for preventing indium metal sputtering contamination in a laser resonant cavity. Background Technology

[0002] High-repetition-rate solid-state lasers are widely used in laser rangefinders, laser pointers, and laser jamming devices. Currently, diode-pumped solid-state lasers (DPSSLs) are widely employed. These products operate in harsh environments, require high reliability, and have long operating times, typically exceeding 10 million cycles. The vast majority of reliability issues with these lasers are caused by laser contamination. Therefore, eliminating contamination in the design and manufacturing process is the only way to fundamentally solve the reliability problem of lasers.

[0003] To dissipate heat, laser crystals are fixed with indium metal in a heat-conducting layer. When exposed to laser radiation, the indium metal sputters and volatilizes, adhering to the laser resonator glass and crystal end faces. This leads to a decrease in optical transmittance or emissivity, resulting in a drop in laser energy. Therefore, indium metal sputtering contamination must be addressed in the design. Summary of the Invention

[0004] This invention provides a method and structure for preventing indium metal sputtering contamination within a laser resonant cavity. It addresses the problem of high-power laser oscillation and reflection within a high-repetition-rate laser cavity, where the laser reflects onto the indium metal in the fixed crystal, causing indium metal to volatilize and adhere to the laser crystal and other optical components, resulting in optical component contamination and a significant reduction in laser output energy.

[0005] To address the above technical problems, this invention provides a method for preventing indium metal sputtering contamination within a laser resonant cavity, characterized by the following steps: setting an indium metal fixing layer between the laser crystal end and the thermal layer; setting a red glass plate on the outer side of the laser crystal end, so that the red glass plate covers and seals the indium metal fixing layer; the red glass plate has high transmittance for 1064nm laser, used to transmit scattered laser light and prevent indium metal volatiles from contaminating the optical components of the resonant cavity.

[0006] A structure for preventing indium metal sputtering contamination in a laser resonant cavity, characterized in that it comprises: a laser crystal; a thermal layer; an indium metal fixing layer disposed between the laser crystal and the thermal layer; and a red glass plate disposed on the outer side of the end of the laser crystal, covering and sealing the indium metal fixing layer; wherein the red glass plate has high transmittance for 1064nm laser.

[0007] Beneficial effects: This invention uses HB850 red glass bonded to the end of the crystal, which has the following effects: First, the HB850 red glass completely seals the indium metal that fixes the crystal, preventing the indium metal from volatilizing; second, the HB850 red glass transmits 1064nm laser light, avoiding the use of other materials to reflect the scattered 1064nm wavelength laser light into the laser resonant cavity and affect the beam quality, thus solving the problem of indium metal sputtering contamination. Attached Figure Description

[0008] Figure 1 Schematic diagram of the structure without red glass Figure 2 Optical path diagram of the laser resonator Figure 3 Schematic diagram of the structure with red glass Figure 4 Design drawing of red glass Detailed Implementation

[0009] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below.

[0010] The present invention proposes a method for preventing indium metal sputtering contamination in a laser resonant cavity, comprising the following steps: setting an indium metal fixing layer between the end of the laser crystal and the thermal layer; setting a red glass plate on the outside of the end of the laser crystal, so that the red glass plate covers and seals the indium metal fixing layer; the red glass plate has high transmittance for 1064nm laser, and is used to transmit scattered laser and prevent indium metal volatiles from contaminating the optical components of the resonant cavity.

[0011] The material of the red glass sheet is HB850 type red glass.

[0012] The red glass plate is semi-circular in shape, and its semi-circular radius is equal to or greater than the radius of the laser crystal end face.

[0013] When the diameter of the laser crystal is Φ7mm, the semi-circular radius of the red glass plate is 3.5mm.

[0014] The thickness of the red glass sheet is 0.5 mm to 2 mm.

[0015] The thickness of the red glass sheet is 1 mm.

[0016] The red glass sheet is bonded and fixed to the heat layer with glass glue and is tightly attached to the end of the laser crystal.

[0017] The present invention also provides a structure for preventing indium metal sputtering contamination in a laser resonant cavity, characterized in that it comprises: a laser crystal; a thermal layer; an indium metal fixing layer disposed between the laser crystal and the thermal layer; and a red glass plate disposed on the outer side of the end of the laser crystal, covering and sealing the indium metal fixing layer; the red glass plate has high transmittance for 1064nm laser and prevents the laser of this wavelength from being reflected back into the resonant cavity and affecting the beam quality.

[0018] The red glass sheet is HB850 type red glass, and its shape is semi-circular.

[0019] The red glass sheet is fixed to the heat layer with glass glue.

[0020] The structure is applied in the resonant cavity of a high repetition rate solid-state laser.

[0021] The laser crystal is the gain medium in a diode-pumped solid-state laser.

[0022] Figure 1 is a schematic diagram of the structure without the red glass, where there is a thin indium solder layer between the thermal layer and the crystal; Figure 2 is an optical path diagram, where a small amount of laser light cannot be reflected to the crystal, but is reflected to the indium solder layer outside the crystal, causing indium to volatilize. The volatilized indium reaches the crystal end face and the reflector, contaminating the optical lens and causing a decrease in laser energy.

[0023] Figure 3 is a schematic diagram of the structure of the present invention with the addition of red glass. The red glass is installed on the heat layer and covers the indium solder layer outside the crystal, so that the indium solder layer cannot evaporate.

[0024] Figure 4 shows the design of the red glass using a Φ7mm crystal as an example. The semicircular arc R = crystal diameter / 2, and in Figure 4, the semicircular arc R is 3.5mm. Other dimensions depend on the size of the heat-resistant layer end face, as shown in Figure 3. A glass thickness of 1mm is sufficient to achieve satisfactory results. The red glass is then firmly attached to the crystal and secured with glass glue. This ensures that the 1064 nm light transmits through the red glass without being reflected back, and that the indium solder layer does not evaporate.

[0025] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preventing indium metal sputtering contamination within a laser resonant cavity, characterized in that, The method includes the following steps: setting an indium metal fixing layer between the laser crystal end and the thermal layer; setting a red glass plate on the outside of the laser crystal end, so that the red glass plate covers and seals the indium metal fixing layer; the red glass plate has high transmittance for 1064nm laser, and is used to transmit scattered laser and prevent indium metal volatiles from contaminating the resonant cavity optical components.

2. The method according to claim 1, characterized in that, The material of the red glass sheet is HB850 type red glass.

3. The method according to claim 1 or 2, characterized in that, The red glass plate is semi-circular in shape, and its semi-circular radius is equal to or greater than the radius of the laser crystal end face.

4. The method according to claim 3, characterized in that, When the diameter of the laser crystal is Φ7mm, the semi-circular radius of the red glass plate is 3.5mm.

5. The method according to claim 1, characterized in that, The thickness of the red glass sheet is 0.5 mm to 2 mm.

6. The method according to claim 5, characterized in that, The thickness of the red glass sheet is 1 mm.

7. The method according to claim 1, characterized in that, The red glass sheet is bonded and fixed to the heat layer with glass glue and is tightly attached to the end of the laser crystal.

8. A structure for preventing indium metal sputtering contamination within a laser resonant cavity, characterized in that, Includes: laser crystals; A thermal layer; an indium metal fixing layer disposed between the laser crystal and the thermal layer; a red glass sheet disposed on the outer side of the end of the laser crystal, covering and sealing the indium metal fixing layer; the red glass sheet has high transmittance for 1064nm laser.

9. The structure according to claim 8, characterized in that, The red glass sheet is HB850 type red glass, and its shape is semi-circular arc. The red glass sheet is fixed to the heat layer with glass glue.

10. The structure according to claim 8, characterized in that, The laser crystal is the gain medium in a diode-pumped solid-state laser.

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