A lamp-pumped miniaturized multiwavelength solid-state laser

Abstract

This invention discloses a lamp-pumped miniaturized multi-wavelength solid-state laser, whose main structure comprises a resonant cavity mirror, a focusing cavity, a composite bonded crystal, a pulsed xenon lamp, a beam splitter, a reflector, a beam shaping system, a light-blocking plate, and a beam combiner. The composite bonded crystal is a cylindrical crystal made by bonding two or more doped laser crystals of the same matrix material to a thin sheet of the matrix material. The doped laser crystals share the same set of highly reflective cavity mirrors, a focusing cavity, and a xenon lamp, and each uses its own set of coupling output cavity mirrors, beam shaping systems, and light-blocking plates to achieve a single wavelength or a combination output of multiple 1-3μm wavelength lasers. Compared with existing technologies, this design reduces the volume and weight of the optical and mechanical structures, facilitating miniaturization and integration. The composite bonded crystal improves the pump light utilization rate and reduces the thermal load on the focusing cavity and crystal rod. The arrangement design of the composite bonded crystal can improve the uniformity of crystal thermal load and enhance the output beam quality.

Description

Technical Field

[0001] This utility model belongs to the field of lasers, specifically relating to a lamp-pumped miniaturized multi-wavelength solid-state laser. Background Technology

[0002] With the development of laser technology, pump sources have gradually evolved from broad-spectrum pump sources such as flash lamps (xenon lamps, krypton lamps, etc.) to narrow-spectrum pump sources such as laser diodes, in order to achieve higher conversion efficiency and beam quality while reducing the thermal load of laser systems. However, to date, flash lamps still play an important role in some practical application scenarios, such as industrial processing and medical aesthetics, where a large amount of pump energy needs to be supplied in a short period of time, which laser diodes are not good at and have high application costs.

[0003] In addition, some laser gain media are not suitable for using laser diodes as pump sources because excessive gain causes very serious thermal effects, affecting key laser parameters such as laser beam quality and output energy, such as 50% doped Er:YAG crystals used to output 2.94μm lasers.

[0004] Currently, lamp-pumped laser technology has already gained market share in some cutting-edge medical and cosmetic fields. For example, in dentistry, xenon lamp-pumped Er:YAG lasers have been certified as the "gold standard" in dental laser treatment; xenon lamp-pumped Nd:YAG lasers have been used in many dermatological medical and cosmetic procedures; and xenon lamp-pumped CTH:YAG lasers have demonstrated significantly superior efficacy compared to traditional medical methods in the field of urinary lithotripsy. With the increasing demand for high-quality medical care, in the fields of dentistry and cosmetic dermatology, treatment methods combining multiple wavelengths of lasers have been proven to be more effective than single-wavelength laser treatments and have been put into practical application. In recent years, many related laser products have emerged. It is understood that the relevant products all adopt a single-cavity, single-type laser crystal material working mode, which brings the following problems: First, the opto-mechanical structure is complex and the equipment is heavy, which is not conducive to miniaturization and integration; Second, the laser crystal only absorbs and utilizes a portion of the wavelength spectrum output by the xenon lamp, while the rest puts a heat load on the laser system, requiring high-power forced cooling to remove the waste heat; Third, for example, 50% doped Er:YAG crystals have extremely poor thermal conductivity. Although in most cases YAG crystals are bonded to the two output ends of the Er:YAG crystal to optimize heat dissipation, due to the shape parameters of the crystal rod, most of the heat needs to be dissipated through the side with a larger surface area (i.e., the pumped light surface). However, the side is generally not specially treated, and the heat dissipation effect is limited. Therefore, the crystal thermal effect is serious, affecting the laser output beam quality, conversion efficiency, and resonant cavity stability. Summary of the Invention

[0005] To address the problems of complex optomechanical structures, single output wavelength, and poor crystal heat dissipation in the background technology, a lamp-pumped miniaturized multi-wavelength solid-state laser is proposed.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A lamp-pumped miniaturized multi-wavelength solid-state laser comprises a laser resonant cavity consisting of a high-reflection resonant cavity mirror and a coupled output cavity mirror, a pump source and pump light homogenization structure consisting of a focusing cavity and a pulsed xenon lamp for side pumping, a composite bonded crystal as the laser gain medium, a beam splitter for separating laser beams of different wavelengths, a light-blocking plate for controlling the output and shut-off of lasers in the corresponding optical paths, a beam shaping system for shaping and transforming the output spot shape, a reflector for guiding and adjusting the laser propagation direction, and a beam combiner for achieving the final laser output.

[0008] The composite bonded crystal has a cylindrical structure, with a central part consisting of two or more laser crystals of the same matrix material but different doping elements bonded together. A cylindrical material of the same matrix material as the doped crystal is coaxially bonded to each of the two circular end faces of the central part. The axial thickness of the cylindrical material does not exceed 2 mm, and the cross-sectional area of ​​the cylinder is the same as that of the central part of the composite bonded crystal. Anti-reflection coatings are deposited on both end faces of the composite bonded crystal.

[0009] Furthermore, for high-reflectivity resonant cavity mirrors, metal mirrors, metal-coated mirrors, or dielectric-coated mirrors are used, with a reflectivity of greater than or equal to 95% for the entire wavelength range of 1~3μm or a specific laser wavelength. For coupling output cavity mirrors, depending on the gain medium used, a cavity mirror with a dielectric coating and a coupling output rate of 10%~30% for the corresponding laser wavelength is selected. The matrix material of the coupling output cavity mirror must have a transmittance of greater than or equal to 90% for wavelengths of 1~3μm, such as calcium fluoride, barium fluoride, magnesium fluoride, etc.

[0010] Furthermore, for pulsed xenon lamps, it is best to have an arc length slightly shorter than the axial length of the focusing cavity, and to place the electrode area in the area through which the coolant passes. This results in less light leakage, better pumping effect, and better heat dissipation.

[0011] Furthermore, the focusing cavity employs a single elliptical structure design, with the reflective inner wall acting as a homogenizer for the pump light, resulting in a more uniform distribution of the pump light irradiating the laser gain medium. For a laser rod outputting wavelengths of 1–3 μm, its absorption spectrum lies in the 0.4–0.9 μm wavelength range, which is also a relatively strong emission band in the xenon lamp emission spectrum. Considering the focusing cavity's reflection effect and the need for residual heat dissipation, specular or diffuse reflective materials are used as the main coating material for the reflective inner wall, such as gold, silver, magnesium oxide, and barium sulfate. These materials achieve a laser reflectivity of 90% or higher in the 0.4–0.9 μm wavelength band. The pulsed xenon lamp and laser gain medium are located near the focal point on the major axis of the elliptical focusing cavity cross-section. Coolant is circulated within the focusing cavity to forcibly remove waste heat from the focusing cavity walls, the pulsed xenon lamp, and the laser gain medium.

[0012] Furthermore, for composite bonded crystals, multiple laser crystals with different dopants but the same matrix are bonded together to form a cylindrical bonded crystal. Then, a cylindrical structure with the same matrix material is bonded to the two circular end faces to form a composite bonded crystal. From a practical perspective, because the laser crystal matrix materials used are the same and have similar melting points, bonding between different laser crystals is easy; moreover, the microstructure of the bonded crystal is more regular, and microstructural defects are less likely to occur. On the one hand, laser excitation can proceed normally; on the other hand, the thermal conductivity of the bonding surface is greatly improved compared to unbonded surfaces. YAG crystal (yttrium aluminum garnet crystal) is widely used as a matrix crystal material in 1~3μm laser materials, such as Nd:YAG (1.064μm), CTH:YAG (2.1μm), Er:YAG (2.94μm), etc.

[0013] Furthermore, two arrangements of the composite bonded crystal structure were designed: parallel arrangement and axial sequence.

[0014] In a side-by-side arrangement, two or more types of doped laser crystals are selected with equal axial lengths, each occupying a certain cross-sectional area, and bonded together to form a complete cylinder. This side-by-side arrangement is suitable for situations where there is significant absorption of laser signal wavelengths between different laser crystals, such as bonding Er:YAG and Nd:YAG crystals.

[0015] In the axial sequence method, two or more doped crystals have the same diameter, and the cylinder heights of the various crystals may be the same or different. The design is based on the target output energy of the crystal and the overall cylinder length, and then they are coaxially bonded in a specific order, such as ABABAB. The axial sequence method is suitable for situations where there is no significant absorption of laser signal wavelength between different laser crystals, such as bonding CTH:YAG and Nd:YAG crystals.

[0016] Furthermore, beam splitters separate the transmission paths of lasers of different wavelengths, facilitating subsequent beam shaping and output. Generally, lenses with a dielectric coating and a reflectivity of ≥99% for wavelength one and a transmittance of ≥99% for wavelength two are used. The lens matrix must be made of a material with a transmittance of ≥90% for wavelengths of 1–3 μm, such as calcium fluoride. When the system outputs more than three wavelengths of laser light, multiple beam splitters are required to separate the multiple beams.

[0017] Furthermore, the beam shaping system selects a material with appropriate transmittance and a lens with a radius of curvature based on factors such as laser wavelength and beam quality, so that the output spot size and distribution shape when the laser reaches the target position meet the expectations.

[0018] Furthermore, the reflector plays a role in guiding and adjusting the direction of laser transmission. Depending on the laser wavelength, a material with high reflectivity for that wavelength is selected as the reflective layer, such as gold, silver, and dielectric film.

[0019] Furthermore, the beam combiner serves as the final beam combiner and direction adjuster. The laser beam is ultimately output from the system after passing through this lens. It needs to be coated with a dielectric film that has high transmittance for the laser wavelength transmitted through the lens and high reflectivity for the laser wavelength reflected through the lens. The lens matrix material should be selected from materials such as calcium fluoride, magnesium fluoride, and barium fluoride.

[0020] Furthermore, a mechanically controlled light-blocking structure is located between the beam shaping system and the beam combiner. In specific applications, it can either not block or block the laser beam path as needed, allowing or preventing laser transmission within the corresponding optical path. This light-blocking structure is placed at an 8° angle to the optical path to prevent the laser from returning to the oscillator along its original path, thus affecting the stability of the laser output.

[0021] The above technical solution can achieve the following beneficial effects:

[0022] This invention utilizes a composite bonded crystal, along with a single focusing cavity and a single xenon lamp, to achieve laser output across multiple wavelengths from 1 to 3 μm. Compared to the traditional lamp-pumped equipment's single-cavity, single-type laser crystal outputting a single wavelength, the reduction in the number of focusing cavities and xenon lamps, as well as the corresponding reduction in servo power supplies, cooling equipment, and piping, significantly reduces the size and weight of the equipment, facilitating the miniaturization and integration of lamp-pumped multi-wavelength lasers. 1-3 μm wavelength lasers currently have significant application demands in laser medicine and aesthetics, and this structure is also well-suited for laser parameter output in these fields. Furthermore, the use of a composite bonded crystal allows for the absorption of a wider spectral range of pump light emitted by the xenon lamp, reducing the overall thermal load of the laser system and lowering its cooling requirements.

[0023] The composite bonded crystal described in this invention enhances the heat dissipation effect of the crystal. Bonding another YAG-based laser crystal to the side or end face of the doped laser crystal allows for improved heat dissipation through this bonding surface, which is more effective than forced cooling by coolant alone. This optimized heat dissipation reduces the thermal load on the crystal, playing a crucial role in mitigating crystal thermal effects, improving laser output beam quality and resonant cavity stability, increasing conversion efficiency, and extending crystal lifespan. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a multi-wavelength solid-state laser based on a side-by-side arrangement.

[0025] Figure 2 This is a schematic diagram of a composite bonded crystal (partial) based on a side-by-side arrangement.

[0026] Figure 3 This is a schematic diagram of a multi-wavelength solid-state laser based on the axial sequence method.

[0027] Figure 4 This is a schematic diagram of a composite bonded crystal (partial) based on the axial sequence method.

[0028] 1. High-reflection resonant cavity mirror; 2. Concentrating cavity; 3. Composite bonded crystal; 4. Pulsed xenon lamp; 5. Beam splitter; 6. Light-blocking plate one; 7. Coupled output cavity mirror one; 8. Beam shaping system one; 9. Reflector one; 10. Light-blocking plate two; 11. Coupled output cavity mirror two; 12. Beam shaping system two; 13. Reflector two; 14. Beam combiner; 31. Nd:YAG crystal; 32. Er:YAG crystal; 33. YAG crystal; 34. CTH:YAG crystal. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings:

[0030] like Figure 1-4 As shown, a lamp-pumped miniaturized multi-wavelength solid-state laser comprises a laser resonant cavity consisting of a high-reflection resonant cavity mirror and a coupled output cavity mirror, a pump source and pump light homogenization structure consisting of a focusing cavity and a pulsed xenon lamp for side pumping, a composite bonded crystal as the laser gain medium, a beam splitter for separating laser beams of different wavelengths, a light-blocking plate for controlling the output and shut-off of lasers in the corresponding optical paths, a beam shaping system for shaping and transforming the output spot shape, a reflector for guiding and adjusting the laser propagation direction, and a beam combiner for achieving the final laser output.

[0031] The composite bonded crystal has a cylindrical structure, with a central part consisting of two or more laser crystals of the same matrix material but different doping elements bonded together. A cylindrical material of the same matrix material as the doped crystal is coaxially bonded to each of the two circular end faces of the central part. The axial thickness of the cylindrical material does not exceed 2 mm, and the cross-sectional area of ​​the cylinder is the same as that of the central part of the composite bonded crystal. Anti-reflection coatings are deposited on both end faces of the composite bonded crystal.

[0032] For high-reflectivity resonant cavity mirrors, metal mirrors, metal-coated mirrors, or dielectric-coated mirrors are used, with a reflectivity of greater than or equal to 95% for the entire wavelength range of 1~3μm or a specific laser wavelength. For coupling output cavity mirrors, depending on the gain medium used, a cavity mirror with a dielectric coating and a coupling output rate of 10%~30% for the corresponding laser wavelength is selected. The matrix material of the coupling output cavity mirror must have a transmittance of greater than or equal to 90% for wavelengths of 1~3μm, such as calcium fluoride, barium fluoride, magnesium fluoride, etc.

[0033] For pulsed xenon lamps, the arc length should be slightly shorter than the axial length of the focusing cavity, and the electrode area should ideally be located in the area through which the coolant passes. This results in less light leakage, better pumping effect, and better heat dissipation.

[0034] The focusing cavity employs a single elliptical structure design, with the reflective inner wall acting as a homogenizer for the pump light, resulting in a more uniform distribution of pump light irradiating the laser gain medium. For the laser rod outputting wavelengths of 1–3 μm, its absorption spectrum lies in the 0.4–0.9 μm wavelength range, which is also a relatively strong emission band in the xenon lamp emission spectrum. Considering the focusing cavity's reflection effect and the need for residual heat dissipation, specular or diffuse reflective materials are used as the main coating material for the reflective inner wall, such as gold, silver, barium sulfate, and magnesium oxide. These materials achieve a laser reflectivity of 90% or higher in the 0.4–0.9 μm wavelength band. The pulsed xenon lamp and laser gain medium are located near the focal point on the major axis of the elliptical focusing cavity cross-section. Coolant is circulated within the focusing cavity to forcibly remove waste heat from the focusing cavity walls, the pulsed xenon lamp, and the laser gain medium.

[0035] For composite bonded crystals, multiple laser crystals with different doping elements but the same matrix are bonded together to form a cylindrical bonded crystal. Then, a cylindrical structure with the same matrix material is bonded to the two circular end faces to form the composite bonded crystal. From a practical perspective, because the laser crystal matrix materials used are the same and have similar melting points, bonding between different laser crystals is easy; moreover, the microstructure of the bonded crystal is more regular, and microstructural defects are less likely to occur. On the one hand, laser excitation can proceed normally; on the other hand, the thermal conductivity of the bonding surface is significantly improved compared to unbonded crystals. YAG crystal (yttrium aluminum garnet crystal) is widely used as a matrix crystal material in 1~3μm laser materials, such as Nd:YAG (1.064μm), CTH:YAG (2.1μm), and Er:YAG (2.94μm).

[0036] Two structural arrangement methods were designed for composite bonded crystals: parallel arrangement and axial sequence.

[0037] In a side-by-side arrangement, two or more types of doped laser crystals are selected with equal axial lengths, each occupying a certain cross-sectional area, and bonded together to form a complete cylinder. This side-by-side arrangement is suitable for situations where there is significant absorption of laser signal wavelengths between different laser crystals, such as bonding Er:YAG and Nd:YAG crystals.

[0038] In the axial sequence method, two or more crystals have the same diameter, and the cylinder heights of the various crystals may be the same or different. The design is based on the target output energy of the crystal and the overall cylinder length, and then they are coaxially bonded in a specific order, such as ABABAB. The axial sequence method is suitable for situations where there is no significant absorption of laser signal wavelengths between different laser crystals, such as bonding CTH:YAG and Nd:YAG crystals.

[0039] Beam splitters separate the transmission paths of lasers of different wavelengths, facilitating subsequent beam shaping and output. They typically employ lenses coated with a dielectric film that has a reflectivity of ≥99% for wavelength one and a transmittance of ≥99% for wavelength two. The lens matrix must be made of a material with a transmittance of ≥90% for wavelengths of 1–3 μm, such as calcium fluoride, barium fluoride, or magnesium fluoride. When separating lasers of three or more wavelengths, multiple beam splitters are required to separate the multiple beams.

[0040] The beam shaping system selects materials with appropriate transmittance and lenses with appropriate curvature radii based on factors such as laser wavelength and beam quality, so that the output spot size and distribution shape when the laser reaches the target position meet the expectations.

[0041] The reflector serves to guide and adjust the direction of laser transmission. Depending on the laser wavelength, a material with high reflectivity for that wavelength is selected as the reflective layer, such as gold, silver, or dielectric film.

[0042] The beam combiner serves as the final beam combiner and direction adjuster. The laser beam is ultimately output from the system after passing through this lens. It needs to be coated with a dielectric film that has a transmittance of ≥99% for laser wavelengths transmitted through the lens and a reflectance of ≥99% for laser wavelengths reflected through the lens. The lens matrix material should be selected from materials such as calcium fluoride, barium fluoride, and magnesium fluoride.

[0043] A mechanically controlled light-blocking plate structure is located between the beam shaping system and the beam combiner. In specific applications, it either does not block or blocks the laser beam path as needed, allowing or preventing laser transmission within the corresponding optical path. The plate is placed at an 8° angle to the optical path to prevent the laser from returning to the oscillator along its original path, thus affecting the stability of the laser output.

[0044] like Figure 1 and Figure 3 As shown, the high-reflection resonant cavity mirror, focusing cavity, composite bonding crystal, pulsed xenon lamp, and beam splitter in the embodiment are assembled according to the laser oscillator structure. Along the optical path, the beam splitter forms two paths. One path is coupled to the output cavity mirror 1, shaped by the beam shaping system 1, and output from the beam combiner 14. The other path passes through the reflector 1, coupled to the output cavity mirror 2, and is reflected by the reflector 2 13 and the beam combiner 14 before being output from the system. Light-blocking plate 1 and light-blocking plate 2 are added to the two paths.

[0045] The following is a detailed explanation based on two sets of embodiments: Example

[0046] like Figure 1 and Figure 2 The accompanying diagram illustrates Example 1. The composite bonded crystal 3 is composed of crystals bonded in a parallel arrangement. Er:YAG crystal 32 and Nd:YAG crystal 31 serve as gain media for generating 2.94μm and 1.064μm lasers, respectively, and are bonded together at their respective rectangular cross-sections. Then, a YAG crystal 33 is bonded to each of the two output end faces of the crystal, and an antireflection coating is deposited on the end face of the YAG crystal 33. The laser is output from the crystal through the rounded end face of the composite bonded crystal 3. The sides of the composite bonded crystal 3 are frosted. The beam splitter 5 is coated with a dielectric film that provides high transmittance for 2.94μm lasers and high reflectivity for 1.064μm lasers, allowing the 2.94μm laser to pass completely through the mirror while completely reflecting the 1.064μm laser. Reflectors 1-9 and 2-13 have high reflectivity for 1.064μm lasers. The beam combiner 14 is coated with a dielectric film that has high transmittance for 2.94μm laser and high reflectivity for 1.064μm laser, so that the 2.94μm laser can completely pass through the lens and the 1.064μm laser is completely reflected by the lens.

[0047] The 2.94μm laser oscillator consists of a high-reflection resonant cavity mirror 1, a focusing cavity 2, a composite bonding crystal 3, a pulsed xenon lamp 4, a beam splitter 5, and a coupling output cavity mirror 7. The beam splitter 5 is ineffective because it allows complete transmission of the 2.94μm laser. The 1.064μm laser oscillator consists of the same components. Beam shaping systems 8 and 12 use lenses with appropriate curvatures to shape the spot size and shape of the 2.94μm and 1.064μm lasers, respectively. Furthermore, since the power supply and cooling system are not key components of this embodiment, they are not described in the embodiment, but they are still essential for the normal operation of the system and will not be elaborated upon here.

[0048] The working principle and process of the laser are described below when the light-blocking plates 6 and 10 do not obstruct the optical path. A pulsed xenon lamp 4 generates pump light, which is reflected by the focusing cavity 2 to uniformly illuminate the side of the composite bonded crystal 3. Excited by the pump light, the composite bonded crystal 3 generates a small signal gain. The 2.94μm laser signal generated by the Er:YAG crystal 32 oscillates in a resonant cavity composed of the high-reflection resonant mirror 1 and the coupling output cavity mirror 7, generating a laser pulse signal. The 1.064μm laser signal generated by the Nd:YAG crystal 31 oscillates in a resonant cavity composed of the high-reflection resonant mirror 1, the beam splitter 5, the reflector 9, and the coupling output cavity mirror 11, generating a laser pulse signal. The 2.94μm laser is shaped by the beam shaping system 8 and output from the system through the beam combiner 14. The 1.064μm laser is shaped by the beam shaping system 12 and output from the system after reflection by the reflector 13 and the beam combiner 14. Furthermore, if only the 1.064μm laser is output, the mechanically controlled light-blocking plate 6 blocks the transmission of the 2.94μm laser; if only the 2.94μm laser is output, the mechanically controlled light-blocking plate 10 blocks the transmission of the 1.064μm laser. The reason for placing light-blocking plates 6 and 10 outside the resonant cavity is that if both the 2.94μm and 1.064μm lasers oscillate and output normally, the thermal effects of the Er:YAG crystal 32 and the Nd:YAG crystal 31 will be significantly reduced. This is beneficial for reducing the overall thermal effect of the composite bonded crystal 3, thereby improving beam quality and conversion efficiency. To address the difference in the spatial position of the light spots generated by the 2.94μm laser and the 1.064μm laser due to excitation at different cross-sectional positions of the composite bonded crystal 3, the spatial transmission optical path of the 1.064μm laser is controlled by adjusting the angles of reflector 9 and reflector 13, so that it completely overlaps with the spatial transmission optical path of the 2.94μm laser after it is output from this system.

[0049] Example 2:

[0050] like Figure 3 and Figure 4 The accompanying drawing illustrates Embodiment 2. The composite bonded crystal 3 is composed of crystals bonded in an axial sequence arrangement. CTH:YAG crystal 34 and Nd:YAG crystal 31 serve as gain media for generating 2.1μm and 1.064μm lasers, respectively, and are coaxially bonded together at their respective circular cross-sections. In this embodiment, the axial length of a single CTH:YAG crystal 34 is equal to the axial length of the Nd:YAG crystal 31. Using an ABAB method, two CTH:YAG crystals 34 and two Nd:YAG crystals 31 are bonded together as the central part of the composite bonded crystal 3. Then, a YAG crystal 33 is bonded to each of the two output end faces of the crystal, and an antireflection coating is deposited on the end face of the YAG crystal 33. The laser outputs from the crystal through the circular end face of the composite bonded crystal 3. The sides of the composite bonded crystal 3 are frosted. Beam splitter 5 is coated with a dielectric film that has high transmittance for 2.1μm lasers and high reflectivity for 1.064μm lasers, allowing the 2.1μm laser to pass completely through the mirror while completely reflecting the 1.064μm laser. Reflectors 1-9 and 13-13 have high reflectivity for 1.064μm lasers. Beam combiner 14 is coated with a dielectric film that has high transmittance for 2.1μm lasers and high reflectivity for 1.064μm lasers, allowing the 2.1μm laser to pass completely through the mirror while completely reflecting the 1.064μm laser.

[0051] The 2.1μm laser oscillator consists of a high-reflection resonant cavity mirror 1, a focusing cavity 2, a composite bonding crystal 3, a pulsed xenon lamp 4, a beam splitter 5, and a coupling output cavity mirror 7. The beam splitter 5 is ineffective because it allows complete transmission of the 2.1μm laser. The 1.064μm laser oscillator consists of the same components. Beam shaping systems 8 and 12 use lenses with appropriate curvatures to shape the spot size and shape of the 2.1μm and 1.064μm lasers, respectively. Furthermore, since the power supply and cooling system are not key components of this embodiment, they are not described in the embodiment, but they are still essential for the normal operation of the system and will not be elaborated upon here.

[0052] The working principle and process of the laser are described below when the light-blocking plates 6 and 10 do not obstruct the optical path. A pulsed xenon lamp 4 generates pump light, which is reflected by the focusing cavity 2 to uniformly illuminate the side of the composite bonded crystal 3. Excited by the pump light, the composite bonded crystal 3 generates a small signal gain. The 2.1μm laser signal generated by the CTH:YAG crystal 34 oscillates in a resonant cavity composed of a high-reflection resonant mirror 1 and a coupling output cavity mirror 7, generating a laser pulse signal. The 1.064μm laser signal generated by the Nd:YAG crystal 31 oscillates in a resonant cavity composed of a high-reflection resonant mirror 1, a beam splitter 5, a reflector 9, and a coupling output cavity mirror 11, generating a laser pulse signal. The 2.1μm laser is shaped by the beam shaping system 8 and output from the system through the beam combiner 14. The 1.064μm laser is shaped by the beam shaping system 12 and output from the system after reflection by the reflector 13 and the beam combiner 14. Furthermore, if only the 1.064μm laser is output, the mechanically controlled light-blocking plate 6 blocks the transmission of the 2.1μm laser; if only the 2.1μm laser is output, the mechanically controlled light-blocking plate 10 blocks the transmission of the 1.064μm laser. To address the potential differences in the spatial positions of the 2.1μm and 1.064μm lasers at their excitation positions on the composite bonded crystal 3 (e.g., due to differences in doping uniformity, pump uniformity, resonant cavity angle, etc.), the spatial transmission path of the 1.064μm laser is controlled by adjusting the angles of the reflector 9 and the reflector 13, ensuring that it completely overlaps with the spatial transmission path of the 2.1μm laser after it exits the system.

[0053] The above descriptions are all preferred embodiments of this utility model. For those skilled in the art, any modifications to this utility model in various equivalent forms without departing from the principle of this utility model shall fall within the protection scope of the appended claims.

Claims

1. A lamp-pumped miniaturized multi-wavelength solid-state laser, characterized in that: The laser resonant cavity is composed of a high-reflection resonant cavity mirror and a coupled output cavity mirror. The pump source and pump light homogenization structure for side pumping are composed of a focusing cavity and a pulsed xenon lamp. The laser gain medium is a composite bonded crystal. The beam splitter separates the laser beams of different wavelengths. The output and shut-off of the corresponding optical path lasers are controlled by a light-blocking plate. The output spot shape is shaped and transformed by a beam shaping system. The laser propagation direction is guided and adjusted by a reflector. The final laser output is achieved by a beam combiner. The composite bonded crystal has a cylindrical structure, with a central part consisting of two or more laser crystals of the same matrix material but different doping elements bonded together. A cylindrical material of the same matrix material as the doped crystal is coaxially bonded to each of the two circular end faces of the central part. The axial thickness of the cylindrical material does not exceed 2 mm, and the cross-sectional area of ​​the cylinder is the same as that of the central part of the composite bonded crystal. Anti-reflection coatings are deposited on both end faces of the composite bonded crystal.

2. The lamp-pumped miniaturized multi-wavelength solid-state laser according to claim 1, characterized in that: The high-reflectivity resonant cavity mirror material is a metal mirror, a metal-coated mirror, or a dielectric-coated mirror, with a reflectivity ≥95% for the full wavelength range of 1~3μm or a specific laser wavelength; the coupling output cavity mirror is a dielectric-coated cavity mirror, with a coupling output rate of 10%~30% for the corresponding laser wavelength, and the transmittance of the coupling output cavity mirror matrix material for the 1~3μm wavelength is ≥90%.

3. The lamp-pumped miniaturized multi-wavelength solid-state laser according to claim 1, characterized in that: The arc length of the pulsed xenon lamp is shorter than the axial length of the focusing cavity, and the electrode area of ​​the pulsed xenon lamp is located in the area through which the coolant passes.

4. A lamp-pumped miniaturized multi-wavelength solid-state laser according to claim 1, characterized in that: The focusing cavity has a single elliptical structure, and the reflective inner wall coating material is a specular reflective material or a diffuse reflective material. The reflectivity of this material for wavelengths of 0.4~0.9μm is ≥90%. The pulsed xenon lamp and the composite bonded crystal are located near the focal point on the long axis of the cross-section of the elliptical focusing cavity, and a coolant flows through the focusing cavity.

5. A lamp-pumped miniaturized multi-wavelength solid-state laser according to claim 1, characterized in that: The diameter of the composite bonded crystal is 4~6mm; the bonding arrangement in the central part of the composite bonded crystal is divided into two types: parallel arrangement and axial sequence arrangement. When arranged side by side, the two or more doped crystals have equal axial lengths and each occupies a certain circular cross-sectional area. After bonding, they form a complete cylinder. When arranged in an axial sequence, the cylindrical cross-sections of two or more doped crystals are complete and have the same diameter, and their axial lengths are equal or unequal. They are coaxially bonded together in a regular sequence. Under this arrangement, the absorption rate of various doped crystals for all signal laser wavelengths excited by the composite bonded crystal is ≤10%.

6. A lamp-pumped miniaturized multi-wavelength solid-state laser according to claim 1, characterized in that: The beam splitter is a lens coated with a dielectric film, and the transmittance of the lens matrix material for wavelengths of 1~3μm is ≥90%. When the beam splitter is used to separate two wavelengths of laser, the reflectance for one wavelength of laser is ≥99%, and the transmittance for the other wavelength of laser is ≥99%. When the system outputs three or more wavelengths of laser, multiple beam splitters need to be configured to achieve multi-path laser separation.

7. A lamp-pumped miniaturized multi-wavelength solid-state laser according to claim 1, characterized in that: The reflective layer material of the reflector is selected according to the laser wavelength, and a material with high reflectivity to the target laser wavelength is selected; the beam combiner is a lens with a dielectric film, and the lens matrix material can be one of calcium fluoride, magnesium fluoride, or barium fluoride. The beam combiner has a transmittance of ≥99% for the transmitted laser wavelength and a reflectivity of ≥99% for the reflected laser wavelength.

8. A lamp-pumped miniaturized multi-wavelength solid-state laser according to claim 1, characterized in that: The light-blocking plate is a mechanically controlled structure made of metal material that has undergone a blackening process. The light-blocking plate is placed at an 8° angle to the beam transmission path and is located outside the resonant cavity.

9. A lamp-pumped miniaturized multi-wavelength solid-state laser according to claim 2, characterized in that: The high-reflectivity resonant cavity mirror is a metal mirror, a metal-plated mirror, or a dielectric-plated mirror, and the metal used in the metal mirror or metal-plated mirror is gold or silver; the matrix material of the coupling output cavity mirror can be one or more of calcium fluoride, magnesium fluoride, and barium fluoride.

10. A lamp-pumped miniaturized multi-wavelength solid-state laser according to claim 4, characterized in that: The coating material for the inner wall of the focusing cavity is selected from one or more of gold, silver, magnesium oxide, and barium sulfate.

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