High-power dual-wavelength erbium-doped solid laser

Abstract

The invention relates to a high-power dual-wavelength erbium-doped solid laser, and belongs to the technical field of laser. The high-power dual-wavelength erbium-doped solid laser comprises a pumping source, a pumping cavity, a diamond, a heat sink, a first resonant cavity and a second resonant cavity, the first resonant cavity comprises a first erbium-doped YAG slice crystal, and the second resonant cavity comprises a second erbium-doped YAG slice crystal. The first erbium-doped YAG sheet crystal is used for generating 1.64 [mu] m laser which oscillates back and forth in a back-and-forth light path provided by the first resonant cavity; and the second erbium-doped YAG sheet crystal is used for generating 2.94 [mu] m laser which oscillates back and forth in a back-and-forth light path provided by the second resonant cavity. According to the high-power dual-wavelength erbium-doped solid laser provided by the invention, synchronous output of 1.64 mu m and 2.94 mu m dual-wavelength laser is realized, the multifunctionality and medical adaptability of the laser are enhanced, and multi-type treatment requirements of soft tissues and hard tissues can be met at the same time.

Description

Technical Field

[0001] This invention belongs to the field of laser technology, and in particular relates to a high-power dual-wavelength erbium-doped solid-state laser. Background Technology

[0002] Er:YAG (erbium-doped yttrium aluminum garnet) crystal is a high-performance solid-state laser material in the mid-infrared band. Belonging to the cubic crystal system, it possesses high density, high hardness, and good thermal stability. This crystal can achieve multi-wavelength laser output at room temperature, primarily including wavelengths of 1.64 μm, 1.78 μm, and 2.94 μm, demonstrating good application scalability and band adaptability. The 1.64 μm and 1.78 μm wavelengths correspond to Er:YAG. 3+ Ions from 4 I 13 / 2 energy level 4 I 15 The transition between the / 2 energy level. These two wavelengths are within the eye-safe band, suitable for medical and industrial environments where operator visual safety is paramount. In particular, the 1.64μm wavelength laser has strong biological tissue penetration capabilities, is moderately absorbed by water molecules, and primarily acts on dermal moisture. In dental soft tissue treatments such as gingivectomy and periodontal pocket cleaning, it exhibits good tissue selectivity and low thermal damage characteristics, helping to reduce postoperative pain and promote tissue healing. Furthermore, this wavelength also has significant applications in medical aesthetics, such as promoting collagen regeneration through thermal stimulation of the dermis, thereby improving skin laxity and fine lines; reducing sebaceous gland activity and sebum secretion; playing an adjunctive therapeutic role in certain pigmentary disorders, improving skin tone evenness; and due to its moderate absorption rate of water and hemoglobin, it can achieve precise targeted treatment without significant damage to surrounding tissues, making it particularly suitable for sensitive areas.

[0003] In contrast, a wavelength of 2.94 μm corresponds to Er 3+ Ions from 4 11 / 2 direction 4 I 13The Er:YAG laser undergoes a transition to the 2 / 2 energy level. This wavelength is located in the region of strong absorption peaks for water and hydroxyl groups, making it highly absorbent by water and hydroxyapatite in biological tissues. Therefore, the laser output of Er:YAG crystals in this wavelength band can be widely used in medical fields such as dentistry, dermatology, and plastic surgery. In dental applications, the 2.94μm laser can be efficiently used for the treatment of hard dental tissues, such as caries removal, tooth preparation, and periodontal treatment. Related studies have shown that this wavelength has a small thermal diffusion range during tissue removal, significantly reducing thermal damage to adjacent tissues, thereby improving the precision and safety of the procedure. In medical aesthetics, this wavelength is suitable for skin remodeling, scar repair, and the treatment of pigmented skin diseases. Due to its high water absorption properties, the Er:YAG laser can precisely ablate epidermal tissue and effectively stimulate collagen remodeling in the dermis, thereby improving skin texture, elasticity, and pigmentation problems, achieving various cosmetic treatment goals.

[0004] The doping concentration of Er:YAG crystals has a significant impact on their laser output characteristics. Generally speaking, when Er... 3+ Different wavelengths of laser output can be achieved by adjusting the doping concentration of ions within the range of 0.2% to 50%. Low-doped Er:YAG crystals tend to emit laser light with a wavelength of 1.64 μm, while high-doping concentrations are more conducive to achieving laser output with a wavelength of 2.94 μm. This concentration-dependent wavelength tunability provides crucial support for the adaptability of Er:YAG crystals in various laser applications, endowing them with high functional scalability.

[0005] Er:YAG crystals not only possess excellent optical qualities but also outstanding physical and chemical stability. Their moderate coefficient of thermal expansion and good thermal conductivity help maintain the thermal stability of lasers under high-power operating conditions. Simultaneously, the crystal exhibits high mechanical strength and hardness, enabling it to withstand significant mechanical and thermal stresses, thereby ensuring the long-term reliability and durability of the laser system.

[0006] However, traditional Er:YAG lasers mostly employ a single-wavelength output mode, typically operating only at a wavelength of 2.94 μm, which limits their application potential in multifunctional medical procedures. To meet the growing clinical demand for "multi-purpose" laser treatment systems, developing an Er:YAG laser capable of simultaneous output of both 1.64 μm and 2.94 μm wavelengths is crucial. Dual-wavelength Er:YAG lasers offer significant advantages: the 1.64 μm wavelength primarily targets water-rich soft tissues, exhibiting excellent tissue penetration and selectivity, making it suitable for soft tissue cutting, coagulation, and anti-inflammatory treatment; while the 2.94 μm wavelength, due to its strong absorption peak in water, can efficiently couple energy to water-containing structures, making it particularly suitable for the efficient vaporization and resection of hard tissues (such as bone or dental tissues). Therefore, this type of laser can simultaneously treat soft and hard tissues in a single treatment, significantly improving surgical efficiency, reducing the need for multiple treatments for patients, and shortening the recovery period. For example, in oral and maxillofacial surgery, a 1.64μm wavelength laser can be used for precise cutting of soft tissue, while a 2.94μm wavelength can be used for efficient treatment of bone tissue. A single device can perform combined operations on both soft and hard tissues, significantly improving treatment convenience and precision. In the field of medical aesthetics, the 1.64μm wavelength can effectively heat the dermis, stimulating collagen regeneration for skin tightening and anti-aging treatments; the 2.94μm wavelength is suitable for precise exfoliation of the epidermis, improving issues such as pigmentation, scars, and abnormal keratin metabolism. The synergistic effect of the two wavelengths allows for addressing both dermal and epidermal issues in a single treatment, thereby improving overall treatment effectiveness and patient satisfaction.

[0007] Therefore, developing a compact, highly efficient, and stable dual-wavelength Er:YAG laser holds significant promise for clinical applications. This laser not only meets diverse medical treatment needs but also provides crucial technological support for the multifunctionality and intelligence of laser medical devices. Summary of the Invention

[0008] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention proposes a high-power dual-wavelength erbium-doped solid-state laser, utilizing Er... 3+ By studying the energy level transition characteristics of ions at different doping concentrations and integrating erbium-doped thin-film crystals with different doping concentrations together using bonding technology, dual-wavelength laser outputs at 1.64 μm and 2.94 μm are achieved, solving the problem of single output wavelength in existing erbium-doped lasers.

[0009] According to a first aspect of the present invention, a high-power dual-wavelength erbium-doped solid-state laser is provided, comprising a pump source, a pump cavity, a diamond, a heat sink, a first resonant cavity, and a second resonant cavity; the first resonant cavity comprises a first erbium-doped YAG thin film crystal, and the second resonant cavity comprises a second erbium-doped YAG thin film crystal; The pump source is used to output a pump laser, which is focused by the pump cavity onto the first erbium-doped YAG thin film crystal and the second erbium-doped YAG thin film crystal; The first erbium-doped YAG thin film crystal is fixed on the second erbium-doped YAG thin film crystal using surface activation bonding technology, and the second erbium-doped YAG thin film crystal is fixed on the surface of a diamond crystal using direct bonding technology. The diamond is fixed between the second erbium-doped YAG thin film crystal and the heat sink. The first erbium-doped YAG thin film crystal has a low doping concentration, Er 3+ The molar percentage is 0.1%-1%; the first erbium-doped YAG thin film crystal is used to generate 1.64 μm laser light by oscillating back and forth in the reciprocating optical path provided by the first resonant cavity; The second erbium-doped YAG thin film crystal has a high doping concentration, Er 3+ The molar percentage is 30%-50%; the second erbium-doped YAG thin film crystal is used to generate 2.94 μm laser light by oscillating back and forth in the round-trip optical path provided by the second resonant cavity.

[0010] Preferably, when the wavelength of the pump laser is 970 nm, the second erbium-doped YAG thin film crystal is simultaneously doped with ytterbium ions (Yb). 3+ As a co-doping element, Yb 3+ The molar percentage is 10%-20%.

[0011] Preferably, the first erbium-doped YAG thin film crystal and the second erbium-doped YAG thin film crystal are disk-shaped.

[0012] Preferably, the thickness of the first erbium-doped YAG thin film crystal and the second erbium-doped YAG thin film crystal are 50 μm-500 μm and the diameter is 3 mm-15 mm.

[0013] Preferably, it also includes a first high-reflectivity mirror, a second high-reflectivity mirror, a first end mirror, a first concave mirror, a second concave mirror, and a second end mirror shared by the first resonant cavity and the second resonant cavity; The first erbium-doped YAG thin-film crystal is used to generate a 1.64 μm laser that oscillates back and forth in the reciprocating optical path provided by the first resonant cavity. Specifically, the first erbium-doped YAG thin-film crystal generates a 1.64 μm laser under pump laser, which is incident on a first high-reflection mirror and a first concave mirror. The 1.64 μm laser incident on the first high-reflection mirror is reflected by a second high-reflection mirror and onto a first end mirror. Part of the 1.64 μm laser is reflected by the first end mirror and continues to oscillate back and forth in the first resonant cavity, while part of the 1.64 μm laser passes through the first end mirror and is output. The 1.64 μm laser incident on the first concave mirror is incident on the second end mirror through the second concave mirror and is reflected and continues to oscillate back and forth in the first resonant cavity. A stable 1.64 μm laser source is formed by outputting through the first end mirror. The second erbium-doped YAG thin-film crystal is used to generate a 2.94 μm laser that oscillates back and forth in the reciprocating optical path provided by the second resonant cavity. Specifically, the second erbium-doped YAG thin-film crystal generates a 2.94 μm laser under pump laser, which is incident on the first high-reflection mirror and the first concave mirror. The 2.94 μm laser incident on the first high-reflection mirror is incident on the first end mirror through the second high-reflection mirror and is reflected to continue oscillating back and forth in the second resonant cavity. The 2.94 μm laser incident on the first concave mirror is incident on the second end mirror through the second concave mirror. Part of the 2.94 μm laser is reflected by the second end mirror to continue oscillating back and forth in the second resonant cavity, and part of the 2.94 μm laser passes through the second end mirror and is output to form a stable 2.94 μm laser source.

[0014] Preferably, the first erbium-doped YAG thin film crystal is coated with an antireflection film of 1.64 μm for pump laser and oscillating laser on the side facing the round-trip optical path, with a transmittance greater than 99.9%; the side facing away from the round-trip optical path is coated with an antireflection film for pump laser, with a transmittance greater than 99.9%; and is also coated with a high reflectance film of 1.64 μm for oscillating laser, with a reflectance greater than 99.9%.

[0015] Preferably, the side of the second erbium-doped YAG thin film facing the round-trip optical path is coated with an anti-reflection film of 2.94 μm for the pump laser and oscillating laser, with a transmittance greater than 99.9%; the side facing away from the round-trip optical path is coated with a high-reflection film of 2.94 μm for the pump laser and oscillating laser, with a reflectance greater than 99.9%.

[0016] Preferably, the first end mirror and the second end mirror are planar partially reflective and partially transmissive films; the side of the first end mirror facing the reciprocating optical path is coated with a partially reflective and partially transmissive film for oscillating laser light of 1.64 μm, with a transmittance range of 1% to 20%, and the side facing away from the reciprocating optical path is coated with an antireflective film for oscillating laser light of 1.64 μm, with a transmittance greater than 99.9%; the side of the second end mirror facing the reciprocating optical path is coated with a partially reflective and partially transmissive film for oscillating laser light of 2.94 μm, with a transmittance range of 1% to 20%, and the side facing away from the reciprocating optical path is coated with an antireflective film for oscillating laser light of 2.94 μm, with a transmittance greater than 99.9%.

[0017] Preferably, the first and second high-reflectivity mirrors are planar high-reflectivity mirrors, and the side facing the reciprocating optical path is coated with a high-reflectivity film for oscillating lasers of 1.64μm and 2.94μm, with a reflectivity greater than 99.9%.

[0018] Preferably, the first concave reflector and the second concave reflector are concave high-reflectivity mirrors, and the side facing the round-trip optical path is coated with a high-reflectivity film for oscillating lasers of 1.64μm and 2.94μm, with a reflectivity greater than 99.9%.

[0019] Compared with the prior art, the above-conceptual technical solution conceived by the invention can achieve the following beneficial effects: (1) This invention proposes a high-power dual-wavelength erbium-doped solid-state laser, utilizing Er 3+ By studying the energy level transition characteristics of ions at different doping concentrations and integrating erbium-doped thin-film crystals with varying doping concentrations using bonding technology, dual-wavelength laser outputs at 1.64 μm and 2.94 μm were achieved. This innovative structural design realizes the integration and unification of dual-wavelength laser output, effectively enhancing the versatility and adaptability of erbium-doped lasers and meeting the diverse needs of various medical procedures, including those involving soft and hard tissues.

[0020] (2) This invention proposes a high-power dual-wavelength erbium-doped solid-state laser, whose structural design fully utilizes the differences in pump light absorption performance of erbium-doped YAG crystals with different doping concentrations. The invention employs a double-layer thin-film crystal structure, placing a low-doped erbium-doped YAG crystal at the front end of the pump direction, allowing the pump light to pass through this low-doped crystal layer first. Due to the low doping concentration and small thickness of this crystal, its single-pass absorption rate of the pump light is relatively low, allowing some pump light to continue propagating to the high-doped erbium-doped YAG thin-film crystal at the rear. Through this structural arrangement, the remaining pump light not absorbed by the low-doped crystal can be fully absorbed by the high-doped crystal, thereby achieving gradient distribution and efficient utilization of pump energy in the two laser gain media. This design not only improves the overall pump efficiency and laser conversion efficiency but also optimizes the power matching of the dual-wavelength output, effectively improving the energy utilization and operational stability of the erbium-doped laser in multimodal medical treatment processes.

[0021] (3) This invention proposes a high-power dual-wavelength erbium-doped solid-state laser, in which both layers of erbium-doped thin-film crystal are processed into thin-film disk-shaped structures. This design ensures that no significant lateral thermal gradient is generated on the crystal surface under continuous high pump power, thereby minimizing the impact of thermal effects and avoiding thermal damage to the crystal. This structure optimizes the heat dissipation capacity of the crystal, enabling it to support higher pump power and thus generate high-power 1.64 μm and 2.94 μm dual-wavelength lasers.

[0022] (4) The high-power dual-wavelength erbium-doped solid-state laser proposed in this invention achieves simultaneous output of 1.64 μm and 2.94 μm dual-wavelength lasers. This not only enhances the multifunctionality and medical adaptability of the laser, enabling it to simultaneously meet the diverse treatment needs of both soft and hard tissues, but also achieves gradient absorption and efficient utilization of pump light energy through the arrangement of doping concentrations, significantly improving pump efficiency and laser conversion efficiency. Simultaneously, the crystal adopts a thin-film disk structure design, effectively reducing the lateral thermal gradient, improving heat dissipation performance, avoiding thermal damage, and ensuring stable operation of the system under high-power pumping. This achieves high-power, dual-wavelength laser output, providing technical support for the miniaturization and high-performance of medical lasers. Attached Figure Description

[0023] Figure 1 This is a structural diagram of a high-power dual-wavelength erbium-doped solid-state laser suitable for dental and cosmetic medical applications, provided as an embodiment of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0025] like Figure 1 As shown, the present invention provides a high-power dual-wavelength erbium-doped solid-state laser suitable for dental and cosmetic medical applications, mainly comprising: a pump source 1, a pump cavity 2, a first erbium-doped YAG thin-film crystal 3, a second erbium-doped YAG thin-film crystal 4, a diamond 5, a heat sink 6, a first resonant cavity 13, and a second resonant cavity 14. The pump source 1 outputs a pump laser, which is focused by the pump cavity 2 onto the first erbium-doped YAG thin-film crystal 3 and the second erbium-doped YAG thin-film crystal 4. The first erbium-doped YAG thin-film crystal 3 generates a 1.64 μm laser; the second erbium-doped YAG thin-film crystal 4 generates a 2.94 μm laser. The first resonant cavity 13 and the second resonant cavity 14 provide round-trip optical paths for the 1.64 μm and 2.94 μm lasers, respectively. The diamond 5 is fixed between the second erbium-doped YAG thin-film crystal 4 and the heat sink 6, and is used to conduct heat between the first erbium-doped YAG thin-film crystal 3 and the second erbium-doped YAG thin-film crystal 4. Heat sink 6 is used to further diffuse the heat conducted by diamond 5 into the cooling water flowing inside it, so as to enhance the heat dissipation effect and ensure the stable operation of the laser under continuous high power.

[0026] The first resonant cavity 13 is used to provide a reciprocating oscillation optical path for the 1.64 μm laser, and mainly includes: a first high-reflection mirror 7, a second high-reflection mirror 8, a first end mirror 9, a first erbium-doped YAG thin film crystal 3, a first concave mirror 10, a second concave mirror 11, and a second end mirror 12.

[0027] The second resonant cavity 14 is used to provide a reciprocating oscillation optical path for the 2.94μm laser, and mainly includes: a first high-reflection mirror 7, a second high-reflection mirror 8, a first end mirror 9, a second erbium-doped YAG thin film crystal 4, a first concave mirror 10, a second concave mirror 11, and a second end mirror 12.

[0028] Specifically, pump source 1 includes, but is not limited to, semiconductor lasers, fiber lasers, and solid-state lasers with output wavelengths of 970 nm and 1470 nm.

[0029] Specifically, pump cavity 2 includes a parabolic mirror and a series of reflecting prisms. The pump laser emitted from pump source 1 is focused through pump cavity 2 onto the first erbium-doped YAG thin film crystal 3 and the second erbium-doped YAG thin film crystal 4. Pump light 1 first passes through the first erbium-doped YAG thin film crystal 3. Due to the low doping concentration and small thickness of this crystal layer, the single absorption rate of pump light 1 is relatively low, and some pump light can still continue to propagate to the high-doped YAG thin film crystal 4 at the rear. The remaining pump light that is not absorbed by the low-doped crystal can be fully absorbed by the high-doped crystal, thereby achieving gradient distribution and efficient utilization of pump energy in the two laser gain media. The first erbium-doped YAG thin film crystal 3 and the second erbium-doped YAG thin film crystal 4 are placed at the focal point of the parabolic mirror. The input pump light is focused onto the first erbium-doped YAG thin film crystal 3 and the second erbium-doped YAG thin film crystal 4 after multiple reflections by the parabolic mirror and the folding prism. In this example, a 48-pass pump structure is adopted, that is, the pump laser passes through the first erbium-doped YAG thin film crystal 3 and the second erbium-doped YAG thin film crystal 4 48 times, which greatly improves the absorption efficiency of the thin film crystal for the pump light.

[0030] Specifically, the first erbium-doped YAG thin film crystal 3 is placed at the front end in the pump direction, with a low doping concentration, which helps to reduce non-radiative energy transfer between upper energy levels and improve... 4 I 13 / 2 energy level lifetime, thereby enhancing laser efficiency, Er 3+ The molar percentage is 0.1%-1%.

[0031] Specifically, the second erbium-doped YAG thin film crystal 4 is placed between the first erbium-doped YAG thin film crystal 3 and the diamond, achieving a high doping concentration, which helps to overcome [the problem] through energy transfer mechanisms (such as cross-relaxation). 4 I 11 The self-termination problem of the / 2 energy level, thus achieving efficient laser emission, Er 3+ The molar percentage is 30%-50%.

[0032] Specifically, when the pump light wavelength is 970 nm, the second erbium-doped YAG thin film crystal 4 with a high doping concentration needs to be simultaneously doped with ytterbium ions (Yb). 3+ As a co-doped element, because Yb 3+ The ions have a high absorption cross-section, enabling them to effectively absorb 970nm pump light and transfer energy to Er through an energy transfer mechanism. 3+ Ions, thereby improving pumping efficiency and enhancing the generation of 2.94μm laser.

[0033] Preferably, Yb 3+The molar percentage of Yb is typically chosen to be in the range of 10–20%. This concentration range provides sufficient pump absorption while maintaining good thermal management and optical performance. Excessive Yb... 3+ Doping concentration can lead to concentration quenching, reducing laser efficiency; while too low a concentration may prevent sufficient absorption of pump light.

[0034] Specifically, the first erbium-doped YAG thin film crystal 3 is fixed onto the second erbium-doped YAG thin film crystal 4 using surface activated bonding (SAB) technology.

[0035] Specifically, the second erbium-doped YAG thin film crystal 4 is fixed on the surface of the diamond 5 crystal using direct bonding technology.

[0036] Specifically, the first erbium-doped YAG thin film crystal 3 serves as both the gain medium for the 1.64 μm laser and the reflecting mirror of the resonant cavity. Therefore, different dielectric films are deposited on both sides of the surface of the first erbium-doped YAG thin film crystal 3. The side facing the resonant cavity is coated with an anti-reflection film for the pump laser and the oscillating laser at 1.64 μm, with a transmittance greater than 99.9%. The side facing away from the resonant cavity is coated with an anti-reflection film for the pump laser, with a transmittance greater than 99.9%. At the same time, a high-reflection film for the oscillating laser at 1.64 μm is also coated, with a reflectivity greater than 99.9%.

[0037] Specifically, the second erbium-doped YAG thin film crystal 4 serves as both the gain medium for the 2.94 μm laser and the reflecting mirror of the resonant cavity. Therefore, different dielectric films are deposited on both sides of the surface of the second erbium-doped YAG thin film crystal 4. The side facing the resonant cavity is coated with an anti-reflection film for the pump laser and oscillating laser at 2.94 μm, with a transmittance greater than 99.9%; the side facing away from the resonant cavity is coated with a high-reflection film for the pump laser and oscillating laser at 2.94 μm, with a reflectivity greater than 99.9%.

[0038] Specifically, the first and second high-reflectivity mirrors are planar high-reflectivity mirrors, and the side facing the resonant cavity is coated with high-reflectivity films of 1.64 μm and 2.94 μm for oscillating lasers, with a reflectivity greater than 99.9%.

[0039] Specifically, the first and second concave reflectors are concave high-reflectivity mirrors, and the side facing the resonant cavity is coated with high-reflectivity films for oscillating lasers of 1.64 μm and 2.94 μm, with a reflectivity greater than 99.9%.

[0040] Specifically, the first end mirror and the second end mirror are planar reflective and transmissive membranes.

[0041] Specifically, the side of the first end mirror facing the resonant cavity is coated with a partially reflective and partially transparent film that reflects 1.64 μm of the oscillating laser light, with a transmittance range of 1% to 20%. The side facing away from the resonant cavity is coated with an antireflective film that reflects 1.64 μm of the oscillating laser light, with a transmittance greater than 99.9%.

[0042] Specifically, the side of the second end mirror facing the resonant cavity is coated with a partially reflective and partially transparent film that reflects 2.94 μm of oscillating laser light with a transmittance range of 1% to 20%, while the side facing away from the resonant cavity is coated with an antireflective film that reflects 2.94 μm of oscillating laser light with a transmittance greater than 99.9%.

[0043] Specifically, the first erbium-doped YAG thin film crystal and the second erbium-doped YAG thin film crystal are thin disk-shaped with a thickness of 50 μm to 500 μm and a diameter of 3 mm to 15 mm.

[0044] The following is combined Figure 1 To illustrate the generation process of a high-power dual-wavelength erbium-doped solid-state laser, a specific example is provided. In this embodiment, a 970nm semiconductor laser with fiber coupling is used as the pump source, which is focused by pump cavity 2 onto a first erbium-doped YAG thin-film crystal 3 and a second erbium-doped YAG thin-film crystal 4. Both thin-film crystals are thin disk-shaped, with a thickness of 220 μm and a diameter of 3 mm. Different dielectric films are deposited on both sides of the thin-film crystals. The side of the first erbium-doped YAG thin-film crystal 3 facing the resonant cavity is coated with a 1.64 μm antireflection film for both the pump laser and the oscillating laser, with a transmittance greater than 99.9%; the side facing away from the resonant cavity is coated with an antireflection film for the pump laser, with a transmittance greater than 99.9%; and simultaneously coated with a 1.64 μm high-reflection film for the oscillating laser, with a reflectivity greater than 99.9%. The second erbium-doped YAG thin-film crystal 4 has a 2.94 μm antireflection coating (greater than 99.9%) on the side facing the resonant cavity, which is resistant to both the pump and oscillating lasers. The side facing away from the resonant cavity has a 2.94 μm high-reflection coating (greater than 99.9%). The first erbium-doped YAG thin-film crystal 3 is fixed to the second erbium-doped YAG thin-film crystal 4 using surface activated bonding (SAB) technology. The second erbium-doped YAG thin-film crystal 4 is fixed to the surface of the diamond crystal 5 using direct bonding technology. The diamond crystal is fixed to a copper heat sink, through which cooling water flows. The diamond crystal conducts the heat generated by the thin-film crystal to the heat sink and further diffuses it into the cooling water flowing inside, enhancing heat dissipation and ensuring stable operation of the laser under continuous high power.

[0045] The first resonant cavity 13 mainly includes: a first high-reflectivity mirror 7, a second high-reflectivity mirror 8, a first end mirror 9, a first erbium-doped YAG thin-film crystal 3, a first concave reflector 10, a second concave reflector 11, and a second end mirror 12. The second resonant cavity 14 mainly includes: a first high-reflectivity mirror 7, a second high-reflectivity mirror 8, a first end mirror 9, a second erbium-doped YAG thin-film crystal 4, a first concave reflector 10, a second concave reflector 11, and a second end mirror 12. The first and second high-reflectivity mirrors are planar high-reflectivity mirrors, and the side facing the resonant cavity is coated with a high-reflectivity film for oscillating lasers of 1.64 μm and 2.94 μm, with a reflectivity greater than 99.9%. The first and second concave reflectors are concave high-reflectivity mirrors, and the side facing the resonant cavity is coated with a high-reflectivity film for oscillating lasers of 1.64 μm and 2.94 μm, with a reflectivity greater than 99.9%. The first and second end mirrors are planar partially reflective and partially transmissive films. The first mirror has a partially reflective and partially transmissive coating on the side facing the resonant cavity, which reflects 1.64 μm of oscillating laser light with a transmittance ranging from 1% to 20%. The side facing away from the resonant cavity has an anti-reflective coating, which reflects 1.64 μm of oscillating laser light with a transmittance greater than 99.9%. The second mirror has a partially reflective and partially transmissive coating on the side facing the resonant cavity, which reflects 2.94 μm of oscillating laser light with a transmittance ranging from 1% to 20%. The side facing away from the resonant cavity has an anti-reflective coating, which reflects 2.94 μm of oscillating laser light with a transmittance greater than 99.9%.

[0046] The first erbium-doped YAG thin-film crystal 3, pumped by a 970nm laser, generates a 1.64 μm laser beam. This laser beam is incident on a first high-reflection mirror 7 and a first concave mirror 10. The 1.64 μm laser beam incident on the first high-reflection mirror 7 is reflected by a second high-reflection mirror 8 and onto a first end mirror 9. Part of the 1.64 μm laser beam is reflected by the first end mirror 9 and continues to oscillate back and forth in the resonant cavity 13, while part of the 1.64 μm laser beam passes through the first end mirror 9 and is output. The 1.64 μm laser beam incident on the first concave mirror 10 is incident on a second end mirror 12 via a second concave mirror 11 and is reflected, continuing to oscillate back and forth in the resonant cavity 13. This laser beam output through the first end mirror 9 forms a stable high-power 1.64 μm laser source.

[0047] The second erbium-doped YAG thin-film crystal 4, pumped by a 970 nm laser, generates a 2.94 μm laser beam. This laser beam is incident on the first high-reflection mirror 7 and the first concave mirror 10. The 2.94 μm laser beam incident on the first high-reflection mirror 7 is then incident on the first end mirror 9 via the second high-reflection mirror 8 and is reflected to continue oscillating back and forth in the resonant cavity 14. The 2.94 μm laser beam incident on the first concave mirror 10 is then incident on the second end mirror 12 via the second concave mirror 11. Part of the 2.94 μm laser beam is reflected by the second end mirror 12 and continues to oscillate back and forth in the resonant cavity 14, while part of the 2.94 μm laser beam passes through the second end mirror 12 and is output to form a stable high-power 2.94 μm laser source.

[0048] This invention proposes a high-power dual-wavelength erbium-doped solid-state laser suitable for dental and cosmetic medical applications. It achieves simultaneous output of 1.64μm and 2.94μm dual-wavelength lasers, enhancing the laser's versatility and medical adaptability to simultaneously meet the diverse treatment needs of both soft and hard tissues. Furthermore, by rationally arranging the doping concentration, it achieves gradient absorption and efficient utilization of pump light energy, significantly improving pump efficiency and laser conversion efficiency. Simultaneously, the crystal employs a thin-film disk structure design, effectively reducing the lateral thermal gradient, improving heat dissipation, preventing thermal damage, and ensuring stable system operation under high-power pumping. This enables high-power, dual-wavelength laser output, providing technical support for the miniaturization and high-performance of medical lasers.

[0049] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-power dual-wavelength erbium-doped solid-state laser, characterized in that, It includes a pump source (1), a pump cavity (2), a diamond (5), a heat sink (6), a first resonant cavity (13), and a second resonant cavity (14); the first resonant cavity (13) includes a first erbium-doped YAG thin film crystal (3), and the second resonant cavity (14) includes a second erbium-doped YAG thin film crystal (4); The pump source (1) is used to output pump lasers which are focused by the pump cavity (2) onto the first erbium-doped YAG thin film crystal (3) and the second erbium-doped YAG thin film crystal (4); The first erbium-doped YAG thin film crystal (3) is fixed on the second erbium-doped YAG thin film crystal (4) using surface activation bonding technology. The second erbium-doped YAG thin film crystal (4) is fixed on the surface of the diamond (5) crystal using direct bonding technology. The diamond (5) is fixed between the second erbium-doped YAG thin film crystal (4) and the heat sink (6). The first erbium-doped YAG thin film crystal (3) has a low doping concentration, Er 3+ The molar percentage is 0.1%-1%; the first erbium-doped YAG thin film crystal (3) is used to generate 1.64 μm laser oscillates back and forth in the reciprocating optical path provided by the first resonant cavity (13); The second erbium-doped YAG thin film crystal (4) has a high doping concentration, Er 3+ The molar percentage is 30%-50%; the second erbium-doped YAG thin film crystal (4) is used to generate 2.94 μm laser oscillates back and forth in the round-trip optical path provided by the second resonant cavity (14).

2. The high-power dual-wavelength erbium-doped solid-state laser as described in claim 1, characterized in that, When the wavelength of the pump laser is 970 nm, the second erbium-doped YAG thin film crystal (4) is simultaneously doped with ytterbium ions (Yb). 3+ As a co-doping element, Yb 3+ The molar percentage is 10%-20%.

3. The high-power dual-wavelength erbium-doped solid-state laser as described in claim 1, characterized in that, The first erbium-doped YAG thin film crystal (3) and the second erbium-doped YAG thin film crystal (4) are disk-shaped.

4. The high-power dual-wavelength erbium-doped solid-state laser as described in claim 3, characterized in that, The thickness of the first erbium-doped YAG thin film crystal (3) and the second erbium-doped YAG thin film crystal (4) is 50 μm-500 μm and the diameter is 3 mm-15 mm.

5. The high-power dual-wavelength erbium-doped solid-state laser as described in claim 1, characterized in that, It also includes a first high-reflection mirror (7), a second high-reflection mirror (8), a first end mirror (9), a first concave mirror (10), a second concave mirror (11), and a second end mirror (12) shared by the first resonant cavity (13) and the second resonant cavity (14). The first erbium-doped YAG thin-film crystal (3) is used to generate a 1.64 μm laser that oscillates back and forth in the reciprocating optical path provided by the first resonant cavity (13). Specifically, the first erbium-doped YAG thin-film crystal (3) generates a 1.64 μm laser under pump laser, which is incident on the first high-reflection mirror (7) and the first concave mirror (10). The 1.64 μm laser incident on the first high-reflection mirror (7) is reflected by the second high-reflection mirror (8) and onto the first end mirror (9). Part of the 1.64 μm laser is reflected by the first end mirror (9) and continues to oscillate back and forth in the first resonant cavity (13). Part of the 1.64 μm laser passes through the first end mirror (9) and is output. The 1.64 μm laser incident on the first concave mirror (10) is incident on the second end mirror (12) through the second concave mirror (11) and is reflected and continues to oscillate back and forth in the first resonant cavity (13). A stable 1.64 μm laser is output through the first end mirror (9). μm laser light source; The second erbium-doped YAG thin film crystal (4) is used to generate a 2.94 μm laser that oscillates back and forth in the reciprocating optical path provided by the second resonant cavity (14). Specifically, the second erbium-doped YAG thin film crystal (4) is used to generate a 2.94 μm laser under pump laser, which is incident on the first high-reflection mirror (7) and the first concave mirror (10). The 2.94 μm laser incident on the first high-reflection mirror (7) is incident on the first end mirror (9) through the second high-reflection mirror (8) and is reflected to continue oscillating back and forth in the second resonant cavity (14). The 2.94 μm laser incident on the first concave mirror (10) is incident on the second end mirror (12) through the second concave mirror (11). Part of the 2.94 μm laser is reflected by the second end mirror (12) to continue oscillating back and forth in the second resonant cavity (14), and part of the 2.94 μm laser passes through the second end mirror (12) and is output to form a stable 2.94 μm laser source.

6. The high-power dual-wavelength erbium-doped solid-state laser as described in claim 5, characterized in that, The first erbium-doped YAG thin film crystal (3) is coated with an anti-reflection film of 1.64 μm for pump laser and oscillating laser on the side facing the round-trip optical path, with a transmittance greater than 99.9%; the side facing away from the round-trip optical path is coated with an anti-reflection film for pump laser, with a transmittance greater than 99.9%; and is also coated with a high reflectance film of 1.64 μm for oscillating laser, with a reflectance greater than 99.9%.

7. The high-power dual-wavelength erbium-doped solid-state laser as described in claim 5, characterized in that, The second erbium-doped YAG thin film crystal (4) is coated with an anti-reflection film of 2.94 μm for pump laser and oscillating laser on the side facing the round-trip optical path, with a transmittance greater than 99.9%; and is coated with a high reflectance film of 2.94 μm for pump laser and oscillating laser on the side facing away from the round-trip optical path, with a reflectance greater than 99.9%.

8. The high-power dual-wavelength erbium-doped solid-state laser as described in claim 5, characterized in that, The first end mirror (9) and the second end mirror (12) are planar partially reflective and partially transmissive films. The side of the first end mirror (9) facing the reciprocating optical path is coated with a partially reflective and partially transmissive film for 1.64 μm of oscillating laser light, with a transmittance range of 1% to 20%. The side facing away from the reciprocating optical path is coated with an anti-reflective film for 1.64 μm of oscillating laser light, with a transmittance greater than 99.9%. The side of the second end mirror (12) facing the reciprocating optical path is coated with a partially reflective and partially transmissive film for 2.94 μm of oscillating laser light, with a transmittance range of 1% to 20%. The side facing away from the reciprocating optical path is coated with an anti-reflective film for 2.94 μm of oscillating laser light, with a transmittance greater than 99.9%.

9. The high-power dual-wavelength erbium-doped solid-state laser as described in claim 5, characterized in that, The first high-reflectivity mirror (7) and the second high-reflectivity mirror (8) are planar high-reflectivity mirrors, and the side facing the reciprocating optical path is coated with a high-reflectivity film for oscillating lasers of 1.64μm and 2.94μm, with a reflectivity greater than 99.9%.

10. The high-power dual-wavelength erbium-doped solid-state laser as described in claim 5, characterized in that, The first concave reflector (10) and the second concave reflector (11) are concave high reflectivity mirrors, and the side facing the round-trip optical path is coated with a high reflectivity film for oscillating lasers of 1.64μm and 2.94μm, with a reflectivity greater than 99.9%.

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