Three-wavelength microchip laser

Abstract

The utility model provides a three-wavelength microchip laser. The three-wavelength microchip laser comprises a semiconductor diode, a first lens, a second laser output mirror group, a first reflecting mirror, a second lens, a first frequency doubling crystal, a second frequency doubling crystal, a first light-emitting mirror group, a second light-emitting mirror group and a third light-emitting mirror group which are arranged in sequence. According to the three-wavelength microchip laser, on the premise that the size of the microchip laser is not increased, high-efficiency polarized 1064nm-wavelength subnanosecond laser output is achieved, three-wavelength lasers are output at the same time through the frequency tripling module, the three-wavelength microchip laser can effectively simplify a light path, the structure is simple, the installation space is greatly reduced, and the cost is reduced. And the miniaturized use requirement of the laser can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser, in particular to a three-wavelength microchip laser. BACKGROUND

[0002] Sub-nanosecond laser technology refers to laser technology with pulse width in nanosecond level. Sub-nanosecond laser has high precision and controllability, and sub-nanosecond laser pulse is short in time and high in energy, which makes it widely used in many fields. At the same time, sub-nanosecond lasers with different wavelengths show their respective advantages in different fields. In the application of scientific research and medical treatment, sub-nanosecond laser is mainly used for micro-nano size analysis of substances, spectral analysis, three-dimensional imaging of laser radar, and can obtain the process of chemical change of substances, molecular morphology, high-precision gas and topography measurement by using its high peak power, high spectral purity and narrow pulse width. In the industrial application, it is mainly used for micro-nano structure processing and internal engraving of transparent hard and brittle materials such as glass.

[0003] However, when multiple wavelengths of sub-nanosecond laser need to be output at the same time to match the multi-field application of laser, the internal structure of the laser becomes more complex due to the output of multiple wavelengths, and the overall structure of the laser is large, which is not conducive to the miniaturization of the use demand.

[0004] Therefore, there is an urgent need for a sub-nanosecond laser which can meet the multi-wavelength use demand and has a simple structure. Content of the utility model

[0005] In order to solve the above technical problems, the three-wavelength microchip laser provided by the present application realizes efficient polarization 1064nm wavelength sub-nanosecond laser output without increasing the volume of the microchip laser, realizes the simultaneous output of three wavelengths of laser through a three-frequency module, and has a simple structure, which is conducive to realizing the miniaturization of the laser.

[0006] The three-wavelength microchip laser provided in the first aspect of the application comprises: a semiconductor diode, a first lens, a second laser output mirror group, a first mirror, a second lens, a first frequency doubling crystal, a second frequency doubling crystal, a first light output mirror group, a second light output mirror group, and a third light output mirror group arranged in sequence; wherein the semiconductor diode is configured to generate first laser; the wavelength of the first laser is a first wavelength; the first lens is configured to collimate the first laser; the second laser output mirror group is configured to convert the first laser into second laser and output, the wavelength of the second laser is a second wavelength, and the first wavelength is less than the second wavelength; the first mirror is configured to reflect the second laser to the second lens; the second lens is configured to focus the second laser to the first frequency doubling crystal; the first frequency doubling crystal is configured to double the frequency of the second laser to the third laser, the wavelength of the third laser is a third wavelength, and the second wavelength is twice the third wavelength; the second frequency doubling crystal is configured to sum the frequencies of the second laser and the third laser to the fourth laser, the wavelength of the fourth laser is a fourth wavelength, and the third wavelength is greater than the fourth wavelength; the first light output mirror group is configured to output the fourth laser and reflect the third laser and the second laser to the second light output mirror group; the second light output mirror group is configured to output the third laser and emit the second laser to the third light output mirror group; and the third light output mirror group is configured to output the second laser.

[0007] In some possible implementation manners, the second laser output mirror group comprises a beam splitting prism, a third lens, a bonding crystal, a second mirror, a third mirror, a laser gain crystal, a first dichroic mirror, a fourth mirror, and a fourth lens arranged in sequence; the beam splitting prism is configured to split the first laser to obtain a first sub-laser and a second sub-laser, send the first sub-laser to the third lens, and emit the second sub-laser to the fourth mirror; the third lens is configured to focus the first sub-laser to the bonding crystal; the bonding crystal is configured to convert the first sub-laser into the second laser and send the second laser to the second mirror; the second mirror is configured to reflect the second laser to the third mirror; the third mirror is configured to reflect the second laser to the laser gain crystal; the fourth mirror is configured to reflect the second sub-laser to the fourth lens; the fourth lens is configured to focus the second sub-laser to the laser gain crystal; the laser gain crystal is configured to increase the power of the second laser by the second sub-laser and output the second laser with the increased power to the first dichroic mirror; and the first dichroic mirror is configured to transmit the second laser with the increased power to the first mirror.

[0008] In some possible implementation manners, the first light output mirror group comprises a second dichroic mirror and a fifth lens; the second dichroic mirror is configured to emit the fourth laser to the fifth lens and reflect the third laser and the second laser to the second light output mirror group; and the fifth lens is configured to collimate and output the fourth laser.

[0009] In some possible implementation manners, the second light output mirror group comprises a third dichroic mirror and a sixth lens; the third dichroic mirror is configured to reflect the third laser to the sixth lens and transmit the second laser to the third light output mirror group; and the sixth lens is configured to collimate and output the third laser.

[0010] In some possible implementation manners, the third light output mirror group comprises a fifth mirror and a seventh lens; the fifth mirror is configured to reflect the second laser to the seventh lens; and the seventh lens is configured to collimate and output the second laser.

[0011] In some possible implementation manners, the first wavelength is 808 nm, the second wavelength is 1064 nm, the third wavelength is 532 nm, and the fourth wavelength is 355 nm.

[0012] In some possible implementation manners, the first dichroic mirror, the second dichroic mirror, the third dichroic mirror, the fifth mirror and the third mirror are arranged to be inclined, and the inclination direction and the inclination angle of the first dichroic mirror, the second dichroic mirror, the third dichroic mirror, the fifth mirror and the third mirror are the same.

[0013] In some possible implementation manners, the first mirror, the second mirror and the fourth mirror are arranged to be inclined, and the inclination direction and the inclination angle of the first mirror, the second mirror and the fourth mirror are the same, and the inclination direction of the first mirror is opposite to that of the third mirror.

[0014] The three-wavelength microchip laser provided in the first aspect of the application can realize efficient polarized 1064 nm sub-nanosecond laser output without increasing the size of the microchip laser, can realize simultaneous output of three different wavelengths of 1064 nm, 532 nm and 355 nm lasers through a three-frequency module, can effectively simplify the optical path, greatly reduce the installation space, and can meet the miniaturization requirement.

[0015] The three-wavelength microchip laser provided in the second aspect of the application comprises: a first light-emitting component, a second light-emitting component, and a third light-emitting component; the first light-emitting component comprises a first semiconductor diode, a first aspherical lens, a second aspherical lens, a first bonding crystal, and a first plano-convex lens arranged in sequence; the first semiconductor diode is configured to generate first laser light, and the wavelength of the first laser light is a first wavelength; the first aspherical lens is configured to collimate the first laser light; the second aspherical lens is configured to focus the first laser light to the first bonding crystal; the first bonding crystal is configured to convert the first laser light into second laser light, and the wavelength of the second laser light is a second wavelength; the first plano-convex lens is configured to collimate and output the second laser light; the second light-emitting component comprises a second semiconductor diode, a third aspherical lens, a fourth aspherical lens, a second bonding crystal, a second plano-convex lens, a first sub-frequency-doubling crystal, a first sub-dichroic mirror, and a third plano-convex lens arranged in sequence; the second semiconductor diode is configured to generate the first laser light; the third aspherical lens is configured to collimate the first laser light; the fourth aspherical lens is configured to focus the first laser light to the second bonding crystal; the second bonding crystal is configured to convert the first laser light into the second laser light; the second plano-convex lens is configured to focus the second laser light to the first sub-frequency-doubling crystal; the first sub-frequency-doubling crystal is configured to frequency-double the second laser light into third laser light; the wavelength of the third laser light is a third wavelength, and the second wavelength is twice the third wavelength; the first sub-dichroic mirror is configured to separate the second laser light and the third laser light, and transmit the third laser light to the third plano-convex lens; the third plano-convex lens is configured to collimate and output the third laser light; the third light-emitting component comprises a third semiconductor diode, a fifth aspherical lens, a sixth aspherical lens, a third bonding crystal, a fourth plano-convex lens, a second sub-frequency-doubling crystal, a third sub-frequency-doubling crystal, a second sub-dichroic mirror, and a fifth plano-convex lens arranged in sequence; the third semiconductor diode is configured to generate the first laser light; the fifth aspherical lens is configured to collimate the first laser light; the sixth aspherical lens is configured to focus the first laser light to the third bonding crystal; the third bonding crystal is configured to convert the first laser light into the second laser light; the fourth plano-convex lens is configured to focus the second laser light to the second sub-frequency-doubling crystal; the second sub-frequency-doubling crystal is configured to frequency-double the second laser light into the third laser light; the third sub-frequency-doubling crystal is configured to sum-frequency generate the second laser light and the third laser light into fourth laser light; the wavelength of the fourth laser light is a fourth wavelength, and the third wavelength is greater than the fourth wavelength; the second sub-dichroic mirror is configured to separate the second laser light and the third laser light from the fourth laser light, and transmit the fourth laser light to the fifth plano-convex lens; and the fifth plano-convex lens is configured to collimate and output the fourth laser light.

[0016] In some possible implementation manners, the first sub-dichroic mirror and the second sub-dichroic mirror are both arranged to be inclined, and the inclination direction and the inclination angle of the first sub-dichroic mirror and the second sub-dichroic mirror are both the same.

[0017] The three-wavelength microchip laser provided in the second aspect of the application realizes efficient polarized 1064nm sub-nanosecond laser output without increasing the volume of the microchip laser, and simultaneously outputs 1064nm, 532nm and 355nm lasers through a three-frequency module. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0019] Figure 1 is a three-wavelength microchip laser provided by the embodiments of the present application;

[0020] Figure 2 is another three-wavelength microchip laser provided by the embodiments of the present application.

[0021] Illustration mark:

[0022] 10-semiconductor diode; 11-first lens;

[0023] 12-second laser output mirror group; 121-beam splitting prism; 122-third lens; 123-bonding crystal; 124-second mirror; 125-third mirror; 126-laser gain crystal; 127-first dichroic mirror; 128-fourth mirror; 129-fourth lens;

[0024] 13-first mirror; 14-second lens; 15-first frequency doubling crystal; 16-second frequency doubling crystal;

[0025] 17-first light output mirror group; 171-second dichroic mirror; 172-fifth lens;

[0026] 18-second light output mirror group; 181-third dichroic mirror; 182-sixth lens;

[0027] 19-third light output mirror group; 191-fifth mirror; 192-seventh lens;

[0028] 20-first light-emitting assembly; 21-first semiconductor diode; 22-first aspherical lens; 23-second aspherical lens; 24-first bonding crystal; 25-first plano-convex lens;

[0029] 30 - second light emitting assembly; 31 - second semiconductor diode; 32 - third aspherical lens; 33 - fourth aspherical lens; 34 - second bonded crystal; 35 - second plano-convex lens; 36 - first sub-harmonic crystal; 37 - first sub-dichroic mirror; 38 - third plano-convex lens;

[0030] 40 - third light emitting assembly; 41 - third semiconductor diode; 42 - fifth aspherical lens; 43 - sixth aspherical lens; 44 - third bonded crystal; 45 - fourth plano-convex lens; 46 - second sub-harmonic crystal; 47 - third sub-harmonic crystal; 48 - second sub-dichroic mirror; 49 - fifth plano-convex lens. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0032] Hereinafter, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", and the like can explicitly or implicitly include one or more features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0033] In addition, in the present application, the orientation terms such as "upper", "lower", "inner", "outer", and the like are defined with respect to the orientation of the components shown in the drawings, and it should be understood that these directional terms are relative concepts, which are used for relative description and clarification, and can be changed accordingly according to the change of the orientation of the components placed in the drawings.

[0034] In order to facilitate the technical solutions of the application, the following first describes some concepts related to the present application.

[0035] Laser gain crystal: in laser operation, in order to form stable laser, there must be light-emitting particles that can form particle inversion, which can be molecules, atoms or ions; some of these particles can exist independently, and some exist in certain materials, and replace the ions in the material, and the material that provides a storage place for the active particles is called a host. The host and the active particles are collectively referred to as laser working material, which is called laser gain crystal in solid-state laser.

[0036] Bonded crystal: is the laser gain crystal and pure or other ion-doped homologous substrate material photo-coupled after the molecular diffusion under high temperature conditions to achieve stable bonding of a crystal.

[0037] Four-level structure: in the process of laser operation, the laser working substance needs to have metastable state structure, that is, there is a suitable energy level system. The energy level system must first have the upper laser level and the lower laser level; in addition, it also needs some other energy levels related to the generation of laser. The usual laser working substance is composed of atomic system containing metastable three-level structure or four-level structure. The four-level structure is composed of pumping level, upper laser level, lower laser level and ground state level. The active particles are pumped from the ground state level to the pumping level, and then jump to the upper laser level by non-radiative transition. Laser emission is generated by the transition from the upper laser level to the lower laser level, and finally the particles complete an energy level cycle by non-radiative transition from the lower laser level to the ground state level.

[0038] Q-switching: by artificially controlling the running state of the laser, the general output of continuous or pulsed laser energy can be emitted in the form of pulse in a very short time, so that the output can obtain several orders of magnitude higher peak power output than continuous working. In the process of artificially controlling the running state of the laser, the quality factor of the laser resonant cavity, that is, the Q value, is mainly controlled to obtain high peak power pulse output. The meaning of Q value is the ratio of the total energy stored in the laser resonant cavity to the energy loss per unit time in the cavity, so Q-switching refers to adjusting the size of Q value, and the common Q-switching method in the laser resonant cavity is to adjust the loss of the resonant cavity, and artificially control the size of the loss to change the Q value of the resonant cavity. The Q-switching process is generally completed through two stages. First, the resonant cavity loss is increased, so that the loss in the cavity is higher than the gain, the Q value is low, and it is difficult to start to produce laser. In order to make the laser start, the population inversion density of the upper laser level will increase continuously; the second stage is when the population inversion density of the upper laser level reaches the maximum, the loss of the resonant cavity is suddenly reduced, the Q value is increased, and the resonant cavity forms a stimulated emission which quickly consumes the stored inversion particle number of the upper level, producing a giant laser pulse.

[0039] Laser frequency doubling: after the laser beam passes through a nonlinear optical crystal or nonlinear optical material, the frequency of the output laser beam is doubled due to nonlinear effect, which is called frequency doubling.

[0040] Laser tripling: after the laser beam passes through a nonlinear optical crystal or nonlinear optical material, the frequency of the output laser beam is three times that of the input laser beam due to nonlinear effect. Tripling frequency usually uses cascading nonlinear process to generate. First, the input beam is frequency-doubled, and then the sum frequency of the frequency-doubled light and the fundamental frequency light is used to realize tripling frequency.

[0041] Three-wavelength laser emission principle: a four-level laser operating system is established, and 808 nm laser is used as pump beam to pump particles from ground state energy level to pumping energy level. Then the particles are transferred from the pumping energy level to the upper laser level by non-radiative transition, and the population inversion is formed between the upper laser level and the lower laser level. The stimulated emission occurs from the upper laser level to the lower laser level to form 1064 nm laser output. By passive Q-switching, the 1064 nm laser is emitted in the form of nanosecond pulse. After amplification, the output 1064 nm nanosecond laser is incident on the KTP frequency doubling crystal through the plano-convex lens. At this time, the 1064 nm laser is called the fundamental frequency light, and the fundamental frequency light is incident on the KTP frequency doubling crystal to achieve good phase matching condition. Under the action of nonlinear effect, energy transfer occurs from the 1064 nm laser to the 532 nm second harmonic laser, which is called frequency doubling, and 532 nm blue laser output is formed. Due to the light-light conversion efficiency of the second harmonic, the emitted laser contains 1064 nm laser and 532 nm laser at the same time, so the KTP third harmonic crystal is used again. The fundamental frequency light is 1064 nm and 532 nm, and under the action of nonlinear effect, energy transfer occurs from the 1064 nm and 532 nm laser to the 355 nm third harmonic laser to form 355 nm laser output. The above process is called frequency mixing.

[0042] Mainstream method for sub-nanosecond laser:

[0043] (1) Semiconductor diode directly emits sub-nanosecond laser: This method adjusts the driving current of semiconductor diode through the driving board, and realizes the direct output of sub-nanosecond laser by adjusting the internal temperature control current of semiconductor. The average power of the sub-nanosecond laser realized by this method is small, the wavelength selection range is narrow, and the control requirement of the circuit is high.

[0044] (2) Using optical fiber structure, using nonlinear effect to realize sub-nanosecond laser output in specially designed gain optical fiber. The pulse waveform of the sub-nanosecond laser realized by this method is not smooth, and the system structure is relatively complex.

[0045] (3) Using active and passive Q-switching methods, semiconductor diode laser pumps solid laser working substance to realize sub-nanosecond laser output. Active Q-switching mainly uses electro-optic Q-switching to control the loss in the resonant cavity by using electro-optic crystal to achieve sub-nanosecond laser output. Passive Q-switching uses the nonlinear absorption effect of saturable absorber to modulate the loss in the resonant cavity to achieve sub-nanosecond laser output. Passive Q-switching does not need external control or driving, which effectively improves the compactness and reliability of the laser.

[0046] However, in the multi-field application requiring simultaneous output of multi-wavelength sub-nanosecond lasers, the internal structure of the laser becomes more complex due to the output of multi-wavelength, and the overall structure of the laser is large, which is not conducive to the miniaturization requirement.

[0047] To solve the above technical problems, the embodiment of the present application provides a three-wavelength microchip laser.

[0048] Figure 1 The three-wavelength microchip laser provided by the embodiment of the present application.

[0049] Referring to Figure 1 The three-wavelength microchip laser provided by the embodiment of the present application comprises a semiconductor diode 10, a first lens 11, a second laser output mirror group 12, a first mirror 13, a second lens 14, a first frequency doubling crystal 15, a second frequency doubling crystal 16, a first light output mirror group 17, a second light output mirror group 18 and a third light output mirror group 19 arranged in sequence.

[0050] The semiconductor diode 10 provides a pump source for the resonant cavity and the amplification module in the second laser output mirror group 12, specifically provides a first laser, and the wavelength of the first laser is a first wavelength. The first wavelength can be 808nm.

[0051] The semiconductor diode 10 sends the first laser to the first lens 11, and the sending path is Figure 1 The light path k1 shown in the figure. The first lens 11 can be an aspherical lens, which collimates the first laser output by the semiconductor diode 10, and the spot aberration after collimation using the aspherical lens is small. The first lens 11 is coated with a high transmission film of 808nm wavelength, and the transmittance is greater than 99.9%.

[0052] The first lens 11 collimates and sends the first laser to the second laser output mirror group 12. The sending path is Figure 1 The light path k2 shown in the figure.

[0053] The second laser output mirror group 12 converts the first laser into a second laser, and the wavelength of the second laser is a second wavelength, and the first wavelength is less than the second wavelength. The second wavelength can be 1064nm.

[0054] Specifically, the second laser output mirror group 12 comprises a beam splitting prism 121, a third lens 122, a bonding crystal 123, a second mirror 124, a third mirror 125, a laser gain crystal 126, a first dichroic mirror 127, and a fourth mirror 128 and a fourth lens 129 arranged in sequence.

[0055] Beam-splitting prism 121 is configured to split the first laser beam at a splitting ratio of 50:50, resulting in a first sub-laser and a second sub-laser, which serve to provide pump light to the resonant cavity and amplification module, respectively. Specifically, after the first laser beam is split, beam-splitting prism 121 transmits the first sub-laser to the third lens 122 via a transmission path of... Figure 1 The optical path k3 shown transmits the second sub-laser to the fourth reflector 128. The transmission path is as follows: Figure 1 The optical path k8 is shown. The wavelengths of both the first and second sub-lasers are the first wavelength.

[0056] The third lens 122 is configured to focus the first sub-laser onto the bonding crystal 123, with the focusing path being... Figure 1 The optical path k4 is shown. The third lens 122 can be an aspherical mirror. The reason for using an aspherical mirror is that the resonant cavity length is short, the focusing aberration of an aspherical mirror is small, and the focal length is short. The third lens 122 is coated with a high-transmittance film with a wavelength of 808nm, and the transmittance is greater than 99.9%.

[0057] The bonding crystal 123 is configured to convert the first sub-laser into a second laser and send the second laser to the second reflector 124 via the following path: Figure 1 The optical path k5 is shown. The bonding crystal 123 may be composed of Nd:YAG crystal and Cr:YAG crystal bonded together (Nd:YAG length 2mm + Cr:YAG length 2mm). The double-end coatings of the bonding crystal 123 form a planar-planar cavity structure, in which Nd:YAG serves as the gain part of the resonant cavity, generating a 1064nm wavelength laser (second laser) through stimulated emission. Cr:YAG serves as the Q-switching part of the resonant cavity, causing the 1064nm wavelength laser generated by Nd:YAG to be output as a sub-nanosecond pulse. The Nd:YAG side is the incident end, coated with a high-transmittance film with a wavelength of 808nm and a transmittance greater than 99.9%, and a high-reflectance film with a wavelength of 1064nm and a reflectance greater than 99.9%. The Cr:YAG side is the output end, coated with a partial-reflection film with a wavelength of 1064nm and a transmittance of 30%-50%.

[0058] The second reflector 124 is configured to receive the second laser emitted by the bonding crystal 123 and transmit the second laser to the third reflector 125, with the reflection path being... Figure 1 The optical path k6 is shown. The function of the second reflector 124 is to change the transmission direction of the laser. It is coated with a high-reflectivity film with a wavelength of 1064nm and a reflectivity greater than 99.9%.

[0059] The third reflector 125 is configured to receive the second laser reflected by the second reflector 124 and reflect the second laser to the laser gain crystal 126, with the reflection path being... Figure 1The light path k7 is shown. The third mirror 125 is configured to change the transmission direction of the laser, and is coated with a high-reflection film for 1064nm wavelength, with a reflectivity greater than 99.9%.

[0060] The fourth mirror 128 is configured to reflect the second sub-laser to the fourth lens 129. The fourth mirror 128 is used to change the transmission direction of the second sub-laser, and the reflection path is Figure 1 The light path k9 is shown. The fourth mirror 128 has an angle of 45° with the incident direction and the exit direction of the second sub-laser, and is coated with a high-reflection film for 808nm wavelength, with a reflectivity greater than 99.9%.

[0061] The fourth lens 129 is configured to focus the second sub-laser to the laser gain crystal 126, specifically, the second sub-laser is focused to the laser gain crystal 126 after passing through the first dichroic mirror 127, and the transmission path is Figure 1 The light paths k10 and k11 are shown. The fourth lens 129 can be the same as the third lens 122, which is an aspheric lens. The fourth lens 129 is coated with a high-transmission film for 808nm wavelength, with a transmission rate greater than 99.9%.

[0062] The laser gain crystal 126 is configured to increase the power of the second laser by the second sub-laser. Specifically, the laser gain crystal 126 can act as a gain medium of the amplification module, after the second sub-laser enters the laser gain crystal 126, the laser gain crystal 126 is excited by the pump light of the second sub-laser, amplifies the second laser, and outputs the second laser of 1064nm wavelength. The laser gain crystal 126 is coated with a high-transmission film for 1064nm & 808nm wavelength at both ends, with a transmission rate greater than 99.9%.

[0063] In this way, from the above light path, two light paths are generated between the first laser emitted from the semiconductor diode 10 and the laser gain crystal 126. One laser is: light path k1 (first laser)→light path k2 (first laser)→light path k3 (first sub-laser)→light path k4 (first sub-laser)→light path k5 (second laser)→light path k6 (second laser)→light path k7 (second laser);

[0064] The other laser is: light path k1 (first laser)→light path k2 (second laser)→light path k8 (second sub-laser)→light path k9 (second sub-laser)→light path k10 (second sub-laser)→light path k11 (second sub-laser).

[0065] The two lasers will be amplified in the laser gain crystal 126, and the laser gain crystal 126 is also configured to send the amplified power of the second laser to the first dichroic mirror 127, and the transmission path is Figure 1The light path k11 is shown. The first dichroic mirror 127 not only transmits the second laser and reflects the second laser, but also changes the transmission path of the second laser. The first dichroic mirror 127 is coated with a high-transmission film for 808 nm at an incident angle of 45° on both ends, with a transmittance greater than 99.9%, and a high-reflection film for 1064 nm, with a reflectance greater than 99.9%.

[0066] The first dichroic mirror 127 is configured to transmit the second laser with increased power to the first mirror 13, and the transmission path is as shown in the light path k12. Figure 1 The light path k12 is shown.

[0067] The first mirror 13 is configured to reflect the second laser to the second lens 14, and the reflection path is as shown in the light path k13. Figure 1 The light path k13 is shown. The first mirror 13 is used to change the transmission direction of the second laser, and the first mirror 13 can be the same as the second mirror 124, which is coated with a high-reflection film for 1064 nm, with a reflectance greater than 99.9%.

[0068] The second lens 14 is configured to focus the second laser to the first frequency doubling crystal 15, and the transmission path is as shown in the light path k14. Figure 1 The light path k14 is shown. The second lens 14 can be a plano-convex lens, which is coated with a high-transmission film for 1064 nm, with a transmittance greater than 99.9%.

[0069] The first frequency doubling crystal 15 is configured to frequency-double the second laser to the third laser and send it to the second frequency doubling crystal 16, and the transmission path is as shown in the light path k15. Figure 1 The light path k15 is shown. The wavelength of the third laser is a third wavelength, and the second wavelength is twice the third wavelength, that is, if the second wavelength is 1064 nm, the third wavelength is 532 nm. The first frequency doubling crystal 15 can be a frequency doubling crystal, which functions to frequency-double the second laser of the second wavelength to the third laser of the third wavelength and output it. The first frequency doubling crystal 15 is coated with a high-transmission film for 1064 nm & 532 nm on both ends, with a transmittance greater than 99.9%.

[0070] The second frequency doubling crystal 16 is configured to sum-frequency the second laser and the third laser to the fourth laser and send it to the first light-emitting lens group 17, and the transmission path is as shown in the light path k16. Figure 1The optical path k16 is shown. The wavelength of the fourth laser is the fourth wavelength, which is greater than the third wavelength. Specifically, the second frequency-doubled crystal 16 can be a third frequency-doubled crystal, whose function is to achieve the ultraviolet laser output of the fourth laser with a wavelength of 355nm by combining the 532nm wavelength third laser emitted from the second frequency-doubled crystal with the 1064nm wavelength second laser. The two ends of the second frequency-doubled crystal 16 are coated with high-transmittance films with wavelengths of 1064nm, 532nm, and 355nm, with a transmittance greater than 99.9%.

[0071] The first exiting mirror group 17 is configured to output the fourth laser and reflect the third and second lasers to the second exiting mirror group 18.

[0072] Specifically, the first light-emitting lens group 17 may include a second dichroic mirror 171 and a fifth lens 172.

[0073] The second dichroic mirror 171 is configured to emit the fourth laser beam to the fifth lens 172, with the transmission path as follows: Figure 1 The optical path k17 shown in the diagram reflects the third and second lasers to the second exiting mirror group 18, and the transmission path is as follows: Figure 1 The optical path k18 is shown in the diagram.

[0074] Specifically, the function of the second dichroic mirror 171 is to separate the fourth laser from the second and third lasers. The incident end of the second dichroic mirror 171 is coated with a high reflectivity film with wavelengths of 1064nm and 532nm at an incident angle of 45°, with a reflectivity greater than 99.9%. The output end is coated with a high transmittance film with a wavelength of 355nm, with a transmittance greater than 99.9%.

[0075] The fifth lens 172 is configured to collimate and output the fourth laser, with the transmission path as follows: Figure 1 As shown in Figure a1, the fifth lens 172 can be a plano-convex lens, which is used to collimate the fourth laser. It is coated with a high-transmission film with a wavelength of 355nm and a transmittance greater than 99.9%.

[0076] The second exiting mirror group 18 is configured to receive the second laser and the third laser reflected by the second dichroic mirror 171, output the third laser, and emit the second laser to the third exiting mirror group 19.

[0077] Specifically, the second light-emitting lens group 18 may include a third dichroic mirror 181 and a sixth lens 182.

[0078] The third dichroic mirror 181 is configured to receive the second and third lasers reflected by the second dichroic mirror 171, and to transmit the third laser to the sixth lens 182, with the transmission path as follows: Figure 1 The optical path k19 shown, and the transmission path for sending the second laser to the third exiting mirror group 19, are as follows: Figure 1 The optical path k20 is shown in the figure.

[0079] Specifically, the third dichroic mirror 181 is configured to separate the second laser and the third laser. The incident end of the third dichroic mirror 181 is coated with a high-reflection film for a 532 nm wavelength at an incident angle of 45°, and the reflectivity is greater than 99.9%. The exit end is coated with a high-transmission film for a 1064 nm wavelength, and the transmittance is greater than 99.9%.

[0080] The sixth lens 182 is configured to collimate and output the third laser, and the transmission path is as shown by a2 in FIG. 13. Figure 1 The sixth lens 182 can be a plano-convex lens, and is configured to collimate the third laser. The sixth lens 182 is coated with a high-transmission film for a 532 nm wavelength, and the transmittance is greater than 99.9%.

[0081] The third light output mirror group 19 is configured to output the second laser.

[0082] Specifically, the third light output mirror group 19 can include a fifth mirror 191 and a seventh lens 192.

[0083] The fifth mirror 191 is configured to receive the second laser output by the third dichroic mirror 181, and reflect the second laser to the seventh lens 192. The transmission path is as shown by the light path k21 in FIG. 13. Figure 1 The fifth mirror 191 is configured to change the transmission path of the second laser. The fifth mirror 191 is coated with a high-reflection film for a 1064 nm wavelength, and the reflectivity is greater than 99.9%.

[0084] The seventh lens 192 is configured to collimate and output the second laser, and the transmission path is as shown by a3 in FIG. 13. Figure 2 The seventh lens 192 can be a plano-convex lens, and is configured to collimate the second laser. The seventh lens 192 is coated with a high-transmission film for a 1064 nm wavelength, and the transmittance is greater than 99.9%.

[0085] The first dichroic mirror 127, the second dichroic mirror 171, the third dichroic mirror 181, the fifth mirror 191, and the third mirror 125 are arranged to be inclined, and the inclination direction and the inclination angle of the first dichroic mirror 127, the second dichroic mirror 171, the third dichroic mirror 181, the fifth mirror 191, and the third mirror 125 are the same. Taking the first dichroic mirror 127 as an example, the first dichroic mirror 127 is arranged to be inclined by 45° in the vertical direction toward the direction away from the semiconductor diode 10.

[0086] The first mirror 13, the second mirror 124 and the fourth mirror 128 are obliquely arranged, and the oblique directions and the oblique angles of the first mirror 13, the second mirror 124 and the fourth mirror 128 are the same. Taking the first mirror 13 as an example, the first mirror 13 is arranged to be oblique by 45° along the vertical direction towards the direction close to the semiconductor diode 10. That is, the oblique direction of the first mirror 13 is opposite to that of the third mirror 125. The central axis of the first mirror 13 is perpendicular to the central axis of the third mirror 125.

[0087] The three-wavelength microchip laser provided by the embodiment of the present application uses a new pumping structure and mainly includes three parts, the first part is a resonant cavity for emitting base frequency light of 1064 nm wavelength, the second part is an amplification module for amplifying the base frequency light of 1064 nm wavelength, and the third part is a frequency doubling module for doubling the base frequency light of 1064 nm wavelength into 532 nm wavelength and tripling the base frequency light of 1064 nm wavelength into 355 nm wavelength. The three-wavelength microchip laser realizes efficient polarized 1064 nm wavelength sub-nanosecond laser output without increasing the volume of the microchip laser, realizes simultaneous output of three different wavelengths of 1064 nm wavelength, 532 nm wavelength and 355 nm wavelength through the tripling frequency module, and effectively simplifies the optical path, greatly reduces the installation space, and can realize the miniaturization use demand.

[0088] It can be understood that the specific numerical values of the first wavelength to the fourth wavelength described above are only exemplary, and in the remaining specific implementation manners, the first wavelength can continue to be adaptively adjusted according to the use demand of the three-wavelength microchip laser, and the second wavelength to the fourth wavelength can be changed according to the change of the first wavelength.

[0089] Figure 2 The three-wavelength microchip laser provided by the embodiment of the present application is another three-wavelength microchip laser.

[0090] Referring to Figure 2 The embodiment of the present application also provides another three-wavelength microchip laser, which includes a first light emitting assembly 20, a second light emitting assembly 30 and a third light emitting assembly 40.

[0091] The first light emitting assembly 20 is configured to generate second laser, the second light emitting assembly 30 is configured to generate third laser, and the third assembly is configured to generate fourth laser.

[0092] Specifically, the first light emitting assembly 20 can include a first semiconductor diode 21, a first aspherical lens 22, a second aspherical lens 23, a first bonded crystal 24 and a first plano-convex lens 25 arranged in sequence.

[0093] The first semiconductor diode 21 is configured to generate a first laser beam and transmit the first laser beam to the first aspherical lens 22, with the transmission path as follows: Figure 2 The optical path m1 is shown. The wavelength of the first laser is the first wavelength. The function of the first semiconductor diode 21 is to provide a pump source to the resonant cavity and amplification module, and the first wavelength can be 808nm.

[0094] The first aspherical lens 22 is configured to collimate the first laser. The first aspherical lens 22 is positioned in the optical path of the first laser, and it transmits the collimated first laser beam to the second aspherical lens 23 via the following transmission path: Figure 2 The optical path m2 is shown. The first laser beam collimated by the first aspherical lens 22 has small spot aberrations. The first aspherical lens 22 is coated with a high-transmission film with a wavelength of 808nm, and the transmittance is greater than 99.9%.

[0095] The second aspherical lens 23 is configured to focus the first laser onto the first bonding crystal 24, with the focusing path as follows: Figure 2 The optical path m3 is shown. The reason for setting up the second aspherical lens 23 is that the resonant cavity length is short, the second aspherical lens 23 has small focusing aberrations and a short focal length. The second aspherical lens 23 is coated with a high-transmission film with a wavelength of 808nm, and the transmittance is greater than 99.9%.

[0096] The first bonding crystal 24 is configured to convert the first laser into a second laser and transmit the second laser to the first plano-convex lens 25, with the transmission path as follows: Figure 2 The optical path m4 is shown. The wavelength of the second laser is a second wavelength, which is greater than the first wavelength, and can be 1064 nm. The first bonding crystal 24 can be composed of Nd:YAG crystal and Cr:YAG crystal bonded together (Nd:YAG length 2 mm + Cr:YAG length 2 mm). The double-end coatings of the first bonding crystal 24 form a planar-planar cavity structure. Nd:YAG acts as the gain part of the resonant cavity, generating a 1064 nm laser through stimulated emission. Cr:YAG acts as the Q-switching part of the resonant cavity, causing the 1064 nm wavelength light generated by Nd:YAG to be output as a sub-nanosecond pulse. The Nd:YAG side is the incident end, coated with a high-transmittance film with a wavelength of 808 nm and a transmittance greater than 99.9% and a high-reflectance film with a wavelength of 1064 nm and a reflectance greater than 99.9%. The Cr:YAG side is the output end, coated with a partially reflective film with a wavelength of 1064 nm and a transmittance of 30%-50%.

[0097] The first plano-convex lens 25 is configured to collimate and output the second laser, with the transmission path as follows: Figure 2 The optical path b1 is shown. The first plano-convex lens 25 is coated with a high-transmittance film with a wavelength of 1064nm, and the transmittance is greater than 99.9%.

[0098] In this way, the first light emitting assembly 20 can convert the first laser into the second laser and output.

[0099] The second light emitting assembly 30 includes a second semiconductor diode 31, a third aspherical lens 32, a fourth aspherical lens 33, a second bonded crystal 34, a second plano-convex lens 35, a first sub-frequency doubling crystal 36, a first sub-dichroic mirror 37, and a third plano-convex lens 38 arranged in sequence.

[0100] The second semiconductor diode 31 is configured to generate the first laser and transmit the first laser to the third aspherical lens 32, and the transmission path is as shown in the light path m5. Among them, the second semiconductor diode 31 can be the same as the first semiconductor diode 21. Figure 2

[0101] The third aspherical lens 32 is arranged on the light path of the first laser, and the third aspherical lens 32 is configured to collimate the first laser and transmit the collimated first laser to the fourth aspherical lens 33, and the transmission path is as shown in the light path m6. The first laser spot aberration after collimation of the third aspherical lens 32 is small. The third aspherical lens 32 can be the same as the first aspherical lens 22, and the third aspherical lens 32 is coated with a high transmission film of 808nm wavelength, and the transmission rate is greater than 99.9%. Figure 2

[0102] The fourth aspherical lens 33 is configured to focus the first laser to the second bonded crystal 34, and the focusing path is as shown in the light path m7. The fourth aspherical lens 33 has small focusing aberration and short focal length. The fourth aspherical lens 33 can be the same as the second aspherical lens 23. The fourth aspherical lens 33 is coated with a high transmission film of 808nm wavelength, and the transmission rate is greater than 99.9%. Figure 2

[0103] The second bonded crystal 34 is configured to convert the first laser into the second laser and transmit the second laser to the second plano-convex lens 35, and the transmission path is as shown in the light path m8. Among them, the second bonded crystal 34 can be the same as the first bonded crystal 24. Figure 2

[0104] The second plano-convex lens 35 is configured to focus the second laser to the first sub-frequency doubling crystal 36, and the focusing path is as shown in the light path m9. The second plano-convex lens 35 is coated with a high transmission film of 1064nm wavelength, and the transmission rate is greater than 99.9%. Figure 2

[0105] The first sub-frequency doubling crystal 36 is configured to frequency-doubling the second laser into the third laser and transmit the third laser to the first sub-dichroic mirror 37, and the transmission path is as shown in the light path m10. Among them, the first sub-frequency doubling crystal 36 can be the same as the first sub-frequency doubling crystal 26. Figure 2 ​​​​​The light path m10 is shown. The wavelength of the third laser is a third wavelength, and the second wavelength is twice the third wavelength. The third wavelength can be 532 nm. The first sub-frequency doubling crystal 36 functions to frequency-double the second laser of 1064 nm wavelength into the third laser of 532 nm wavelength and output. The first sub-frequency doubling crystal 36 is coated with a high-transmission film of 1064 nm & 532 nm wavelength at both ends, and the transmittance is greater than 99.9%.

[0106] The first sub-dichroic mirror 37 is configured to separate the second laser and the third laser, and transmit the third laser to the third plano-convex lens 38, and the transmission path is as shown by b1 in the light path m10. Figure 2 The light path m11 is shown, and the second laser is reflected at the same time, as shown by b2 in the light path m11. Figure 2 The first sub-dichroic mirror 37 is obliquely arranged, and the incident end of the first sub-dichroic mirror 37 is coated with a high-reflection film of 1064 nm wavelength at an incident angle of 45°, and the reflectance is greater than 99.9%, and the exit end is coated with a high-transmission film of 532 nm wavelength, and the transmittance is greater than 99.9%.

[0107] The third plano-convex lens 38 is configured to collimate and output the third laser, and the transmission path is as shown by b2 in the light path m10. Figure 2 The third plano-convex lens 38 is coated with a high-transmission film of 532 nm wavelength, and the transmittance is greater than 99.9%.

[0108] In this way, the second light-emitting assembly 30 can convert the first laser into the third laser and output.

[0109] The third light-emitting assembly 40 includes a third semiconductor diode 41, a fifth aspherical lens 42, a sixth aspherical lens 43, a third bonding crystal 44, a fourth plano-convex lens 45, a second sub-frequency doubling crystal 46, a third sub-frequency doubling crystal 47, a second sub-dichroic mirror 48, and a fifth plano-convex lens 49 arranged in sequence.

[0110] Specifically, the third semiconductor diode 41 is configured to generate the first laser, and the transmission path is as shown by the light path m13. Figure 2 The third semiconductor diode 41 can be the same as the first semiconductor diode 21.

[0111] The fifth aspherical lens 42 is arranged on the light path of the first laser, and the fifth aspherical lens 42 is configured to collimate the first laser and transmit the first laser to the sixth aspherical lens 43, and the transmission path is as shown by the light path m14. Figure 2 The fifth aspherical lens 42 can be the same as the first aspherical lens 22.

[0112] The sixth aspherical lens 43 is configured to focus the first laser to the third bonding crystal 44, and the transmission path is as shown by the light path m15. Figure 2 The sixth aspherical lens 43 can be the same as the second aspherical lens 23.

[0113] The third bonding crystal 44 is configured to convert the first laser into a second laser, with the transmission path as follows: Figure 2 The optical path m16 is shown. The third bonding crystal 44 can be the same as the first bonding crystal 24.

[0114] The fourth plano-convex lens 45 is configured to focus the second laser onto the second sub-frequency doubling crystal 46, with the focusing path as follows: Figure 1 The optical path shown is m17. The fourth plano-convex lens 45 is coated with a high-transmittance film at a wavelength of 1064nm, with a transmittance greater than 99.9%.

[0115] The second sub-frequency doubling crystal 46 is configured to double the frequency of the second laser to a third laser, and then transmit the third laser to the third sub-frequency doubling crystal 47, with the transmission path as follows: Figure 2 The optical path m18 is shown. The second sub-frequency doubling crystal 46 has high-transmittance films at both ends with wavelengths of 1064nm and 532nm, and the transmittance is greater than 99.9%.

[0116] The third sub-frequency doubling crystal 47 is configured to combine the frequencies of the second and third lasers to obtain a fourth laser. Specifically, it sends the un-frequency-combined second and third lasers, along with the frequency-combined fourth laser, to the second dichroic mirror. The transmission path is as follows: Figure 1 The optical path m19 is shown. The wavelength of the fourth laser is the fourth wavelength, which is greater than the third wavelength; the fourth wavelength can be 355nm. The third sub-frequency doubling crystal 47 can be a third-frequency doubling crystal, whose function is to combine the second-frequency-harvested 532nm wavelength third laser with the unharvested 1064nm wavelength second laser to achieve a 355nm wavelength ultraviolet laser output. The two ends of the third sub-frequency doubling crystal 47 are coated with high-transmittance films for wavelengths of 1064nm, 532nm, and 355nm, with a transmittance greater than 99.9%.

[0117] The second sub-dichroic mirror 48 is configured to separate the second laser, the third laser, and the fourth laser, and to send the fourth laser to the fifth plano-convex lens 49, with the transmission path as follows: ​ The optical path m20 shown simultaneously reflects the second and third lasers, with the reflection path as follows: ​ The optical path m21 is shown. The second sub-dichroic mirror 48 is tilted. The incident end of the second sub-dichroic mirror 48 is coated with a high-reflectivity film with wavelengths of 1064nm & 532nm at an incident angle of 45°, with a reflectivity greater than 99.9%. The exit end is coated with a high-transmission film with a wavelength of 355nm, with a transmittance greater than 99.9%.

[0118] The fifth plano-convex lens 49 is configured to collimate and output the fourth laser, with the output path as follows: ​ As shown in b3, the fifth plano-convex lens 49 has a high-transmission coating with a wavelength of 355nm, and a transmittance greater than 99.9%.

[0119] Specifically, the first sub color separating mirror 37 and the second sub color separating mirror 48 are both obliquely arranged, and the oblique directions and the oblique angles of the first sub color separating mirror 37 and the second sub color separating mirror 48 are both the same. Wherein, the first sub color separating mirror 37 is arranged to be oblique by 45° along the vertical direction towards the direction close to the third semiconductor diode 41.

[0120] ​ The three-wavelength microchip laser shown in the specification realizes three-wavelength sub-nanosecond laser output through three separate crystals, and has the advantages of The three-wavelength microchip laser in the specification has the same effect as the three-wavelength microchip laser in the specification, and can realize high-efficiency polarized 1064nm wavelength sub-nanosecond laser output, and realize simultaneous output of 1064nm wavelength, 532nm wavelength and 355nm wavelength laser through a three-frequency module. ​ The three-wavelength microchip laser in the specification has the same effect as the three-wavelength microchip laser in the specification, and can realize high-efficiency polarized 1064nm wavelength sub-nanosecond laser output, and realize simultaneous output of 1064nm wavelength, 532nm wavelength and 355nm wavelength laser through a three-frequency module. ​ The three-wavelength microchip laser in the specification has the same effect as the three-wavelength microchip laser in the specification, and can realize high-efficiency polarized 1064nm wavelength sub-nanosecond laser output, and realize simultaneous output of 1064nm wavelength, 532nm wavelength and 355nm wavelength laser through a three-frequency module. ​ The three-wavelength microchip laser in the specification is different from the three-wavelength microchip laser in the specification in installation space, and the specific structure of the three-wavelength microchip laser can be adjusted according to the actual installation space.

[0121] It should be noted that other embodiments of the application will occur to those skilled in the art after considering the specification and the practice of the disclosed application. The application is intended to cover any variations, uses, or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the application pertains.

[0122] It should be understood that the application is not limited to the precise construction that has been described above and shown in the accompanying drawings, and that various modifications and changes can be effected therein by those skilled in the art without departing from the scope of the application. The true scope of the application is set forth in the appended claims.

Claims

1. A three-wavelength microchip laser, characterized by, The semiconductor diode (10), the first lens (11), the second laser output mirror group (12), the first mirror (13), the second lens (14), the first frequency doubling crystal (15), the second frequency doubling crystal (16), the first light output mirror group (17), the second light output mirror group (18) and the third light output mirror group (19) are sequentially arranged. The semiconductor diode (10) is configured to generate a first laser; the wavelength of the first laser is a first wavelength. The first lens (11) is configured to collimate the first laser. The second laser output mirror group (12) is configured to convert the first laser into a second laser and output, the wavelength of the second laser is a second wavelength, and the first wavelength is less than the second wavelength. The first mirror (13) is configured to reflect the second laser to the second lens (14). The second lens (14) is configured to focus the second laser to the first frequency doubling crystal (15). The first frequency doubling crystal (15) is configured to double the frequency of the second laser to a third laser, the wavelength of the third laser is a third wavelength, and the second wavelength is twice the third wavelength. The second frequency doubling crystal (16) is configured to sum frequency of the second laser and the third laser to a fourth laser, the wavelength of the fourth laser is a fourth wavelength, and the third wavelength is greater than the fourth wavelength. The first light output mirror group (17) is configured to output the fourth laser and reflect the third laser and the second laser to the second light output mirror group (18). The second light output mirror group (18) is configured to output the third laser and emit the second laser to the third light output mirror group (19). The third light output mirror group (19) is configured to output the second laser. The second laser output mirror group (12) comprises a beam splitter prism (121), a third lens (122), a bonding crystal (123), a second mirror (124), a third mirror (125), a laser gain crystal (126), a first dichroic mirror (127), a fourth mirror (128) and a fourth lens (129) arranged in sequence.

2. The three-wavelength microchip laser of claim 1, wherein, The beam splitter prism (121) is configured to split the first laser to obtain a first sub-laser and a second sub-laser, and send the first sub-laser to the third lens (122) and emit the second sub-laser to the fourth mirror (128). The third lens (122) is configured to focus the first sub-laser to the bonding crystal (123). The bonding crystal (123) is configured to convert the first sub-laser into the second laser and send the second laser to the second mirror (124). The second mirror (124) is configured to reflect the second laser to the third mirror (125). The third mirror (125) is configured to reflect the second laser to the laser gain crystal (126). The fourth mirror (128) is configured to reflect the second sub-laser to the fourth lens (129). ​ The fourth lens (129) is configured to focus the second sub-laser to the laser gain crystal (126); The laser gain crystal (126) is configured to increase the power of the second laser by the second sub-laser, and output the second laser with increased power to the first dichroic mirror (127); The first dichroic mirror (127) is configured to transmit the second laser with increased power to the first reflector (13).

3. The three-wavelength microchip laser according to claim 2, wherein The first light output lens group (17) comprises a second dichroic mirror (171) and a fifth lens (172); The second dichroic mirror (171) is configured to transmit the fourth laser to the fifth lens (172), and reflect the third laser and the second laser to the second light output lens group (18); The fifth lens (172) is configured to collimate and output the fourth laser.

4. The three-wavelength microchip laser according to claim 3, wherein The second light output lens group (18) comprises a third dichroic mirror (181) and a sixth lens (182); The third dichroic mirror (181) is configured to reflect the third laser to the sixth lens (182), and transmit the second laser to the third light output lens group (19); The sixth lens (182) is configured to collimate and output the third laser.

5. The three-wavelength microchip laser according to claim 4, wherein The third light output lens group (19) comprises a fifth reflector (191) and a seventh lens (192); The fifth reflector (191) is configured to reflect the second laser to the seventh lens (192); The seventh lens (192) is configured to collimate and output the second laser.

6. The three-wavelength microchip laser according to claim 5, wherein The first wavelength is 808 nm, the second wavelength is 1064 nm, the third wavelength is 532 nm, and the fourth wavelength is 355 nm.

7. The three-wavelength microchip laser according to claim 6, wherein The first dichroic mirror (127), the second dichroic mirror (171), the third dichroic mirror (181), the fifth reflector (191), and the third reflector (125) are arranged to be inclined, and the inclination direction and inclination angle of the first dichroic mirror (127), the second dichroic mirror (171), the third dichroic mirror (181), the fifth reflector (191), and the third reflector (125) are the same.

8. The three-wavelength microchip laser according to claim 7, wherein The first reflector (13), the second reflector (124), and the fourth reflector (128) are arranged to be inclined, and the inclination direction and inclination angle of the first reflector (13), the second reflector (124), and the fourth reflector (128) are the same, wherein the inclination direction of the first reflector (13) is opposite to that of the third reflector (125).

9. A three-wavelength microchip laser, characterized by, Comprising: a first light-emitting assembly (20), a second light-emitting assembly (30) and a third light-emitting assembly (40); the first light-emitting assembly (20) comprises a first semiconductor diode (21), a first aspherical lens (22), a second aspherical lens (23), a first bonded crystal (24), a first plano-convex lens (25) arranged in sequence; wherein the first semiconductor diode (21) is configured to generate a first laser, the wavelength of the first laser being a first wavelength; the first aspherical lens (22) is configured to collimate the first laser; the second aspherical lens (23) is configured to focus the first laser to the first bonded crystal (24); the first bonded crystal (24) is configured to convert the first laser into a second laser, the wavelength of the second laser being a second wavelength, the first wavelength being smaller than the second wavelength; the first plano-convex lens (25) is configured to collimate and output the second laser; the second light-emitting assembly (30) comprises a second semiconductor diode (31), a third aspherical lens (32), a fourth aspherical lens (33), a second bonded crystal (34), a second plano-convex lens (35), a first sub-frequency doubling crystal (36), a first sub-dichroic mirror (37) and a third plano-convex lens (38) arranged in sequence; the second semiconductor diode (31) is configured to generate the first laser; the third aspherical lens (32) is configured to collimate the first laser; the fourth aspherical lens (33) is configured to focus the first laser to the second bonded crystal (34); the second bonded crystal (34) is configured to convert the first laser into the second laser; the second plano-convex lens (35) is configured to focus the second laser to the first sub-frequency doubling crystal (36); the first sub-frequency doubling crystal (36) is configured to double the frequency of the second laser into a third laser; the wavelength of the third laser being a third wavelength, the second wavelength being twice the third wavelength; the first sub-dichroic mirror (37) is configured to separate the second laser and the third laser, and send the third laser to the third plano-convex lens (38); the third plano-convex lens (38) is configured to collimate and output the third laser; the third light-emitting assembly (40) comprises a third semiconductor diode (41), a fifth aspherical lens (42), a sixth aspherical lens (43), a third bonded crystal (44), a fourth plano-convex lens (45), a second sub-frequency doubling crystal (46), a third sub-frequency doubling crystal (47), a second sub-dichroic mirror (48) and a fifth plano-convex lens (49) arranged in sequence; the third semiconductor diode (41) is configured to generate the first laser; the fifth aspherical lens (42) is configured to collimate the first laser; the sixth aspherical lens (43) is configured to focus the first laser to the third bonded crystal (44); the third bonded crystal (44) is configured to convert the first laser into the second laser; The fourth plano-convex lens (45) is configured to focus the second laser to the second sub-frequency-doubling crystal (46); The second sub-frequency-doubling crystal (46) is configured to frequency-double the second laser to the third laser; The third sub-frequency-doubling crystal (47) is configured to sum-frequency generate the second laser and the third laser into a fourth laser; the fourth laser has a fourth wavelength, and the third wavelength is greater than the fourth wavelength; The second sub-dichroic mirror (48) is configured to separate the second laser and the third laser from the fourth laser, and send the fourth laser to the fifth plano-convex lens (49); The fifth plano-convex lens (49) is configured to collimate and output the fourth laser.

10. The three-wavelength microchip laser according to claim 9, wherein The first sub-dichroic mirror (37) and the second sub-dichroic mirror (48) are both obliquely arranged, and the first sub-dichroic mirror (37) and the second sub-dichroic mirror (48) have the same oblique direction and the same oblique angle.

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