Solid laser

Abstract

The invention discloses a solid laser, which relates to the technical field of lasers and comprises a pumping source, a slab crystal assembly, a retroreflector, a turning prism and an output mirror, the retroreflector, the turning prism and the output mirror can form a resonant cavity; the lath crystal assembly is arranged in the resonant cavity; the pumping source comprises two pumping modules, the two pumping modules are arranged on the two sides of the lath crystal assembly respectively, and a non-light-emitting area of each pumping module is provided with a reflecting face. Each pumping module is used for emitting pumping light to the lath crystal assembly, at least part of the pumping light emitted by each pumping module can be absorbed by the lath crystal assembly, and the reflecting surface of each pumping module can reflect the pumping light which is not absorbed by the lath crystal assembly back to the lath crystal assembly. The device can operate without temperature control in a wide environment temperature area.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser, in particular to a solid laser. BACKGROUND

[0002] The solid laser is widely used in laser ranging, laser irradiation and laser imaging equipment, and is important optoelectronic equipment. The typical technical route of the solid laser in such equipment is to use a laser diode to pump a Nd:YAG crystal combined with active or passive Q-switching, and finally output a laser pulse with a wavelength of 1.064 μm, a pulse width of about 10 ns, and a single pulse energy of several tens of millijoules to several joules.

[0003] Since the precision temperature control type solid laser has the disadvantages of high power consumption, large volume and weight, and cannot realize instant-on (needs preheating after starting), the solid laser without temperature control becomes a major research direction. The temperature control-free laser is also called temperature control-free laser, which mainly has the following technical routes: First, the end-pumping structure + round bar laser crystal is used as the core design. Since the end-pumping method has the advantage of long absorption length, when the wavelength of the laser diode changes due to the change of the ambient temperature, the laser still has a certain absorption efficiency, and can maintain the laser energy basically unchanged. However, the safe injection energy of the pump light into the laser crystal is small, and the single resonant cavity cannot output large energy. When the end face is pumped, the end of the laser crystal is seriously heated, and the thermal effect of the crystal is serious.

[0004] Second, the side-pumping method is used. Since it is difficult to realize long absorption length with the side-pumping method, when the wavelength of the laser diode changes due to the change of the ambient temperature, and the wavelength is just at the trough of the absorption spectrum of the laser crystal, the absorption efficiency of the laser crystal to the pump light will decrease significantly, and the efficiency of the laser will decrease sharply, and the efficiency of the laser will be very low. Therefore, the side-pumping method generally uses multiple laser diode bars to stack, and cooperates with the current compensation method to make the output laser energy more stable. SUMMARY

[0005] The purpose of the present application is to provide a solid laser to solve the problems existing in the prior art, and to facilitate the realization of temperature control-free operation in a wide environmental temperature range.

[0006] To achieve the above purpose, the present application provides the following scheme: The application provides a solid laser, which comprises a pump source, a slab crystal assembly, a back reflector, a turning prism and an output mirror; the back reflector, the turning prism and the output mirror can form a resonant cavity; the slab crystal assembly is arranged in the resonant cavity; the pump source comprises two pump modules, the two pump modules are arranged on the two sides of the slab crystal assembly respectively, and the non-light-emitting area of each pump module is provided with a reflecting surface; each pump module is used for emitting pump light to the slab crystal assembly, the pump light emitted by each pump module can be at least partially absorbed by the slab crystal assembly, and the reflecting surface of each pump module can reflect the pump light which is not absorbed by the slab crystal assembly back to the slab crystal assembly.

[0007] Preferably, the slab crystal assembly comprises at least three Nd:YAG slab crystals and at least two YAG slab crystals, all the Nd:YAG slab crystals and all the YAG slab crystals extend in the same direction, all the Nd:YAG slab crystals and all the YAG slab crystals are alternately bonded, the two slab crystals on the outermost sides of the slab crystal assembly in the width direction are respectively a first Nd:YAG slab crystal and an Nth Nd:YAG slab crystal, N is an integer greater than or equal to three; the back reflector is arranged opposite to the first end of the first Nd:YAG slab crystal; the turning prism is at least two, one turning prism is arranged at each end of the Mth Nd:YAG slab crystal, 1

[0008] Preferably, the slab crystal assembly further comprises a passive Q-switching crystal, the passive Q-switching crystal is bonded at the end of the Nth Nd:YAG slab crystal; the output mirror is arranged at one end of the passive Q-switching crystal away from the Nth Nd:YAG slab crystal.

[0009] Preferably, the longitudinal section of the slab crystal assembly is isosceles trapezoidal or parallelogram-shaped, and the contour size of any longitudinal section of the slab crystal assembly is completely the same.

[0010] Preferably, the oscillation laser wavelength anti-reflection films are arranged on both end faces of the plate crystal assembly in the length direction.

[0011] Preferably, the light-reflecting medium films are arranged on both end faces of the plate crystal assembly in the height direction, and the refractive index of the light-reflecting medium films is less than the refractive index of the Nd:YAG plate crystal.

[0012] Preferably, each of the pump modules comprises at least one laser diode array, each of the laser diode arrays comprises a plurality of laser diode bars arranged in sequence and at intervals, and the light emitting faces of each of the laser diode bars are directed towards one side face of the plate crystal assembly in the width direction.

[0013] Preferably, each of the pump modules further comprises a plurality of heat dissipation strips, one of the heat dissipation strips is arranged on each side of each of the laser diode bars, and each of the heat dissipation strips is provided with a reflective layer on the side face close to the plate crystal assembly.

[0014] Preferably, the backward reflector is a corner cube prism, each of the turning prisms is a corner cube prism, the output mirror is a Gaussian output mirror, and the passive Q-switching crystal is a Cr4+:YAG crystal.

[0015] Preferably, the Nd:YAG plate crystal is three, and the YAG plate crystal is two.

[0016] The present application has the following technical effects relative to the prior art: The present application provides a solid-state laser, wherein the pump source comprises two pump modules, the two pump modules are arranged on the two sides of the plate crystal assembly, the non-light emitting area of each of the pump modules is provided with a reflective surface, each of the pump modules is used for emitting pump light to the plate crystal assembly, at least part of the pump light emitted by each of the pump modules can be absorbed by the plate crystal assembly, and the reflective surface of each of the pump modules can reflect the pump light not absorbed by the plate crystal assembly back to the plate crystal assembly.

[0017] The part of the pump light emitted by each of the pump modules and not absorbed can be reflected back and forth between the reflective surfaces of the two pump modules until all of the pump light is absorbed by the plate crystal assembly, so that the solid-state laser has a longer absorption length of the pump light, even when the wavelength of the pump light changes due to the change of the ambient temperature, most of the pump light can be absorbed by the plate crystal assembly, so that the temperature of the pump source does not need to be precisely controlled, which is beneficial to the temperature control-free operation in a wide ambient temperature range. BRIEF DESCRIPTION OF DRAWINGS

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 The optical schematic diagram of the solid-state laser provided by this invention; Figure 2 This is a schematic diagram of the structure of the slab crystal assembly provided by the present invention; Figure 3 A front view of the slab crystal assembly provided by the present invention; Figure 4 for Figure 3 Top view; Figure 5 for Figure 3 The back view; Figure 6 This is a schematic diagram of the laser diode array of the present invention; In the diagram, 100 is the solid-state laser; 1 is the pump source; 101 is the pump module; 102 is the laser diode bar; 103 is the heat sink; 104 is the light-emitting area; 2 is the slab crystal assembly; 201 is the Nd:YAG slab crystal; 202 is the YAG slab crystal; 203 is the passively Q-switched crystal; 204 is the antireflection coating for the oscillating laser wavelength; 205 is the optically rarefied dielectric film; 3 is the back reflector; 4 is the deflection prism; and 5 is the output mirror. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that in the description of this invention, the terms "upper," "lower," "left," "right," "inner," "outer," "front," "rear," "center," "longitudinal," "transverse," "length," "width," "thickness," "vertical," "horizontal," "top," "bottom," "clockwise," and "counterclockwise," etc., indicating directional or positional relationships, are based on the directional or positional relationships shown in the accompanying drawings. These are merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Additionally, it should be noted that in the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or a connection within two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] The purpose of this invention is to provide a solid-state laser to solve the problems existing in the prior art, which is conducive to achieving temperature control-free operation in a wide range of ambient temperatures.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figures 1-6As shown, the present invention provides a solid-state laser 100, including a pump source 1, a slab crystal assembly 2, a back reflector 3, a deflector prism 4, and an output mirror 5; the back reflector 3, all deflector prisms 4, and output mirror 5 can form a resonant cavity, and the slab crystal assembly 2 is disposed within the resonant cavity; the pump source 1 includes two pump modules 101, which are respectively disposed on both sides of the slab crystal assembly 2, and each pump module 101 has a reflective surface in its non-emitting region 104; each pump module 101 is used to emit pump light to the slab crystal assembly 2, and at least part of the pump light emitted by each pump module 101 can be absorbed by the slab crystal assembly 2, and the reflective surface of each pump module 101 can reflect the pump light that is not absorbed by the slab crystal assembly 2 back to the slab crystal assembly 2. The unabsorbed portion of the pump light emitted by each pump module 101 can be reflected back and forth between the reflective surfaces of the two pump modules 101 until it is completely absorbed by the slab crystal assembly 2. This gives the solid-state laser 100 a longer pump light absorption length. Even if the pump light wavelength changes due to changes in ambient temperature, most of the pump light can still be absorbed by the slab crystal assembly 2. Therefore, there is no need to precisely control the temperature of the pump source 1, which is beneficial for achieving temperature-controlled operation in a wide ambient temperature range.

[0025] In some embodiments, the slab crystal assembly 2 includes at least three Nd:YAG slab crystals 201 and at least two YAG slab crystals 202. All Nd:YAG slab crystals 201 and all YAG slab crystals 202 extend in the same direction and are alternately bonded. The two outermost slab crystals in the width direction of the slab crystal assembly 2 are the first Nd:YAG slab crystal 201 and the Nth Nd:YAG slab crystal 201, respectively, where N is an integer greater than or equal to three. The rear reflector 3 is disposed opposite to the head end of the first Nd:YAG slab crystal 201. There are at least two deflecting prisms 4, with one deflecting prism 4 disposed at each end of the Mth Nd:YAG slab crystal 201. 1 < M < N, where M is an integer; the output mirror 5 is positioned opposite to the end of the Nth Nd:YAG slab crystal 201; at least a portion of the pump light emitted by each pump source 1 can be absorbed by the Nd:YAG slab crystal 201 to generate photons; a bend prism 4 at the end of the Mth Nd:YAG slab crystal 201 can cause some photons in the (M-1)th Nd:YAG slab crystal 201 to be reflected from the (M-1)th Nd:YAG slab crystal 201 to the Mth Nd:YAG slab crystal 201; another bend prism 4 at the end of the Mth Nd:YAG slab crystal 201 can cause some photons in the Mth Nd:YAG slab crystal 201 to be reflected from the Mth Nd:YAG slab crystal 201 to the (M+1)th Nd:YAG slab crystal 201.

[0026] Pump source 1 emits pump light into slab crystal assembly 2. Nd:YAG slab crystal 201 serves as the laser gain medium, acting as energy storage and stimulated laser emission. YAG crystal acts as an intermediate crystal, connecting the other crystals in slab crystal assembly 2 together. Pump source 1 emits pump light from the side. The pump light enters the first Nd:YAG slab crystal 201, where some is absorbed. The unabsorbed pump light passes through YAG slab crystal 202 to the next Nd:YAG slab crystal 201 and is partially absorbed. Based on this principle, pump light can be transmitted through multiple Nd:YAG slab crystals 201. 3+ After absorption, the ion transitions from the ground state to an excited state (resulting in population inversion). The excited-state ion then undergoes spontaneous emission, generating initial photons. These photons are reflected back and forth within a resonant cavity consisting of a back reflector 3 (acting as a total reflection mirror), an internal prism 4, and an output mirror 5. Specifically, when the laser beam from the first Nd:YAG slab crystal 201 is emitted to the back reflector 3, it is reflected back along the same path, initiating the first round trip. The laser beam from the first Nd:YAG slab crystal 201 is reflected by the prism 4 to the second Nd:YAG slab crystal 201, and the laser beam from the second Nd:YAG slab crystal 201 is reflected by the prism 4 to the third Nd:YAG slab crystal 201. The laser light from the Nd:YAG slab crystal 201, up to the (N-1)th Nd:YAG slab crystal 201, is reflected by the deflecting prism 4 to the Nth Nd:YAG slab crystal 201, and finally transmitted to the output mirror 5. A portion of the light (e.g., 50%) is output as useful laser light through the output mirror 5 and exits the resonant cavity, while the other portion (e.g., 50%) is reflected back into the resonant cavity for the next cycle. Based on this principle, photons can be reflected multiple times within the resonant cavity (in a zigzag pattern among multiple Nd:YAG slab crystals 201). During transmission within the resonant cavity, photons extract energy from each Nd:YAG crystal (stimulated emission). The heat source (pump light energy) is distributed across multiple independent Nd:YAG slab crystals 201, rather than concentrated in a single Nd:YAG slab crystal 201, thus dispersing the heat load and increasing the heat dissipation area. The solid-state laser 100 of this invention can operate without temperature control over a wide ambient temperature range.

[0027] In some embodiments, the slab crystal assembly 2 further includes a passively Q-switched crystal 203, which is bonded to the end of the Nth Nd:YAG slab crystal 201; the output mirror 5 is disposed at the end of the passively Q-switched crystal 203 away from the Nth Nd:YAG slab crystal 201, that is, the output mirror 5 is disposed opposite to the end face of the passively Q-switched crystal 203 away from the Nth Nd:YAG slab crystal 201.

[0028] In some embodiments, the longitudinal section of the slat crystal assembly 2 is an isosceles trapezoid or a parallelogram, and the outer contour dimensions of any longitudinal section of the slat crystal assembly 2 are exactly the same.

[0029] In some embodiments, an oscillating laser wavelength antireflection film 204 is provided on both end faces of the slab crystal assembly 2 along its length.

[0030] In some embodiments, an optically rarefied dielectric film 205 is disposed on both end faces of the slab crystal assembly 2 in the height direction. The refractive index of the optically rarefied dielectric film 205 is lower than that of the Nd:YAG slab crystal 201. The optically rarefied dielectric film 205 can perform total internal reflection of the pump light incident on it, causing part of the pump light to return to the laser medium, thereby improving the absorption efficiency.

[0031] In some embodiments, each pump module 101 includes at least one laser diode array, each laser diode array including a plurality of laser diode bars 102 arranged sequentially at intervals, the light-emitting surface of each laser diode bar 102 facing one side of the slab crystal assembly 2 in the width direction.

[0032] In some embodiments, each pump module 101 further includes multiple heat sinks 103, and each laser diode bar 102 has a heat sink 103 on both sides; each heat sink 103 has a reflective layer on the side near the slab crystal assembly 2.

[0033] In some embodiments, the back reflector 3 is a cornerstone prism, a total reflection mirror, each of the transition prisms 4 is a cornerstone prism, and the output mirror 5 is a Gaussian-type output mirror 5, using a passively Q-switched 203Cr4+:YAG crystal. Because cornerstone prisms have self-collimating reflection characteristics—that is, regardless of the direction from which the incident light enters the cornerstone prism, the reflected light is parallel to the incident light—the laser uses a cornerstone prism as a total reflection mirror and two cornerstone prisms as transition prisms 4, resulting in extremely high resonant cavity stability. The resonant cavity is insensitive to casing deformation caused by changes in ambient temperature, casing deformation caused by impact and vibration, and casing deformation caused by localized heating. The laser can maintain the resonant cavity in a collimated state in various extreme environments, ensuring stable output laser energy. The output mirror 5 of the laser uses a Gaussian-type output mirror, which can effectively improve the beam quality of the laser output.

[0034] In some embodiments, there are three Nd:YAG lath crystals 201 and two YAG lath crystals 202.

[0035] In some embodiments, the slab crystal assembly 2 is composed of two longer Nd:YAG crystals of the same size, one shorter Nd:YAG crystal, two YAG crystals of the same size, and one Cr4+:YAG crystal bonded together as a single unit using a bonding process. The Nd:YAG crystal serves as the laser gain medium, storing energy and stimulating laser emission. The YAG crystal acts as an intermediate crystal, connecting the various crystals together. The Cr4+:YAG crystal performs passive Q-switching. The two longer Nd:YAG crystals have a light-transmitting cross-section of 5mm × 5mm and a small bottom surface (…). Figure 2 The top surface (shown) is 40mm long with a 45° chamfer on the end face. A shorter Nd:YAG crystal has a light-transmitting cross-section of 5mm × 5mm and a small bottom surface length of approximately 35mm. When the shorter Nd:YAG crystal is bonded to a Cr₄⁺:YAG crystal of approximately 5mm length, its length along the optical axis is the same as that of the longer Nd:YAG crystal. The YAG crystal has a cross-sectional dimension of 8mm × 5mm perpendicular to the optical axis, a small bottom surface length of 40mm, and a chamfer on the end face similar to that of the longer Nd:YAG crystal.

[0036] One side of the first, longer Nd:YAG crystal is polished, and this side is bonded to one side of another first YAG crystal, both of which are polished. The other polished side of this YAG crystal is then bonded to one side of a second Nd:YAG crystal, both of which are polished. The other polished side of this Nd:YAG crystal is then bonded to another second YAG crystal, both of which are polished. A shorter Nd:YAG crystal is bonded to the end face of a Cr4+:YAG crystal. After bonding, one side of the bonded assembly is polished, and this polished side is then bonded to the second YAG crystal. This completes the fabrication of the slab crystal assembly 2.

[0037] The two sides of the slab crystal assembly 2 are machined to have a rough surface, the two end faces are coated with an antireflection film 204 with an oscillating laser wavelength incident at 45°, and the two bottom surfaces are polished and coated with a photosensitive dielectric film 205, preferably a SiO2 film. Then, the two bottom surfaces of the slab crystal assembly 2 are welded together with two copper heat sinks to quickly dissipate the waste heat generated in the crystal.

[0038] The laser's output mirror 5 is a Gaussian type. The laser employs two sets of laser diode arrays to pump the crystal from two sides of the slab crystal assembly 2. The heat sinks of the laser diode arrays are mounted on the laser housing, conducting the generated waste heat to the housing and dissipating it into the air.

[0039] The heat sink 103 is preferably a tungsten-copper heat sink. The pump laser diode array does not require a collimating micropillar lens, meaning the fast axis divergence angle of the pump light pumped into the crystal is large, approximately 40°. The emitting areas 104 of the pump laser diode array are spaced 0.6 mm apart, and each laser diode bar 102 (single bar) is 10 mm long. A set of laser diode arrays consists of 3 columns of bars, each column containing 8 bars, with a 2 mm gap between the 3 columns. The total emitting area of ​​the laser diode array is approximately 34 mm × 4.2 mm. A set of laser diode arrays has 24 non-collimated bars, each bar with a peak power of 200 W, for a total peak power of 4800 W. Each bar's emitting area 104 is 1 μm wide, and a tungsten-copper heat sink approximately 0.6 mm thick absorbs the waste heat of the bar (the emitting areas 104 of the laser diode bars are spaced 0.6 mm apart, with a tungsten-copper heat sink between two laser diode bars). A reflective layer, preferably gold-plated, is deposited on the 0.6 mm thick tungsten copper heatsink to make it highly reflective of the pump light. Since the area of ​​the bar light-emitting region 104 is very small, 1 μm × 10 mm, almost the entire 34 mm × 5.4 mm pump area of ​​the laser diode array is a gold-plated reflective region.

[0040] The emitting surface of the laser diode array is 1 mm away from the side of the slab crystal assembly 2. When the pump light emitted by the laser diode array enters the slab crystal assembly 2, light rays with smaller divergence angles propagate directly forward, while light rays with larger divergence angles propagate forward a distance before incident on the bottom surface of the crystal, undergoing total internal reflection and continuing to propagate forward. During its propagation within the crystal, if the pump light encounters an Nd:YAG crystal, some energy is absorbed, while the unabsorbed pump light continues to propagate. If the pump light encounters a YAG crystal during its propagation within the crystal, no energy is absorbed, but after total internal reflection by the YAG crystal, the pump light becomes more uniform; one of the functions of the YAG crystal is to homogenize the pump light. The pump light propagates to the other side of the crystal, during which it is absorbed by three Nd:YAG crystals with a cross-section of 5 mm × 5 mm, for a total absorption length of 15 mm. The unabsorbed pump light exits from the side of the crystal and is incident on the laser diode array opposite. The laser diode array is mostly gold-plated. Unabsorbed pump light is reflected back to the crystal by the gold-plated surface of the laser diode array, where it is transmitted and absorbed again, continuing until it reaches the end face of the laser diode array that emits the pump light. At this point, the absorption length of the pump light by the slab crystal assembly 2 has reached 30mm. The pump light is then reflected back to the crystal by the gold-plated surface of the laser diode array that emits the pump light, and the transmission and absorption continue. This process repeats until the pump light is completely absorbed.

[0041] The pump light emitted by the laser diode array placed on the other side of the slab crystal assembly 2 also undergoes the same process, and the pump light is continuously absorbed.

[0042] This design of the laser diode array and slab crystal assembly 2 allows for a long pump light absorption length. Even if changes in ambient temperature cause variations in the laser diode temperature, resulting in a change in the wavelength of the emitted pump light, most of the pump light will still be absorbed by the slab crystal assembly 2 even if it falls within the trough region of the Nd:YAG crystal absorption spectrum. Therefore, this laser does not require precise temperature control of the laser diode. Regardless of the ambient temperature, the emitted pump light can be efficiently absorbed by the laser crystal, achieving wide-range, temperature-controlled operation of the laser.

[0043] In summary, this laser invention incorporates a slab crystal assembly 2, which allows pump light to propagate repeatedly within it, achieving efficient absorption of the pump light. Furthermore, the slab crystal exhibits minimal thermal effect, enabling the laser to operate at a high repetition rate. A gold-plated, all-reflective laser diode array is also invented, allowing pump light incident upon it to be efficiently reflected back into the laser crystal for continued propagation and absorption, effectively increasing the absorption length of the laser crystal. A resonant cavity consisting of an all-reflective corner prism, a corner prism for the deflecting optical path, and a Gaussian output mirror 5 is invented. This achieves the resonant cavity's insensitivity to the deflection of the cavity mirror and corner prism, ensuring the resonant cavity remains collimated in various extreme environments, guaranteeing stable output laser energy and high output laser beam quality. Moreover, the optical path, after being deflected by the corner prism, passes through the three Nd:YAG crystals in the slab crystal assembly 2, effectively extracting the internal energy stored in the three Nd:YAG crystals and achieving high-energy laser output. The Q-switched crystal (Cr4+:YAG crystal) of the laser is directly bonded to the interior of the slab crystal assembly 2, making the laser structure compact, reducing the size and weight of the laser.

[0044] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A solid-state laser, characterized in that: The system includes a pump source, a slab crystal assembly, a rear reflector, a deflector prism, and an output mirror. The rear reflector, the deflector prism, and the output mirror form a resonant cavity. The slab crystal assembly is disposed within the resonant cavity. The pump source includes two pump modules, which are respectively disposed on both sides of the slab crystal assembly. Each pump module has a reflective surface in its non-emitting region. Each pump module emits pump light into the slab crystal assembly. At least a portion of the pump light emitted by each pump module can be absorbed by the slab crystal assembly, and the reflective surface of each pump module can reflect the pump light that is not absorbed by the slab crystal assembly back to the slab crystal assembly.

2. The solid-state laser according to claim 1, characterized in that: The lath crystal assembly includes at least three Nd:YAG lath crystals and at least two YAG lath crystals. All Nd:YAG lath crystals and all YAG lath crystals extend in the same direction and are alternately bonded. The two outermost lath crystals in the width direction of the lath crystal assembly are the first Nd:YAG lath crystal and the Nth Nd:YAG lath crystal, respectively, where N is an integer greater than or equal to three. The rear reflector is positioned opposite to the head end of the first Nd:YAG lath crystal. There are at least two folding prisms, with one folding prism at each end of the Mth Nd:YAG lath crystal, where 1 < M < N. The value is an integer; the output mirror is positioned opposite to the end of the Nth Nd:YAG slab crystal; at least a portion of the pump light emitted by each pump source can be absorbed by the Nd:YAG slab crystal to generate photons; one of the turning prisms at the end of the Mth Nd:YAG slab crystal can cause a portion of the photons in the (M-1)th Nd:YAG slab crystal to be reflected from the (M-1)th Nd:YAG slab crystal to the Mth Nd:YAG slab crystal; the other turning prism at the end of the Mth Nd:YAG slab crystal can cause a portion of the photons in the Mth Nd:YAG slab crystal to be reflected from the Mth Nd:YAG slab crystal to the (M+1)th Nd:YAG slab crystal.

3. The solid-state laser according to claim 2, characterized in that: The slab crystal assembly also includes a passively Q-switched crystal, which is bonded to the end of the Nth Nd:YAG slab crystal; the output mirror is disposed at the end of the passively Q-switched crystal away from the Nth Nd:YAG slab crystal.

4. The solid-state laser according to claim 1, characterized in that: The longitudinal section of the slat crystal assembly is an isosceles trapezoid or a parallelogram, and the outer contour dimensions of any longitudinal section of the slat crystal assembly are exactly the same.

5. The solid-state laser according to claim 1, characterized in that: An antireflective coating with an oscillating laser wavelength is provided on both end faces of the slab crystal assembly along its length.

6. The solid-state laser according to claim 2, characterized in that: A light-diffuse dielectric film is disposed on both end faces of the lath crystal assembly in the height direction. The refractive index of the light-diffuse dielectric film is less than that of the Nd:YAG lath crystal.

7. The solid-state laser according to claim 1, characterized in that: Each of the pump modules includes at least one laser diode array, and each laser diode array includes a plurality of laser diode bars arranged sequentially at intervals, with the light-emitting surface of each laser diode bar facing one side of the slab crystal assembly in the width direction.

8. The solid-state laser according to claim 7, characterized in that: Each of the pump modules further includes multiple heat sinks, and each of the laser diode bars has a heat sink on both sides; each of the heat sinks has a reflective layer on the side near the slab crystal assembly.

9. The solid-state laser according to claim 3, characterized in that: The rear reflector is a corner cube prism, each of the aforementioned turning prisms is a corner cube prism, the output mirror is a Gaussian output mirror, and the passively Q-switched crystal is a Cr... 4+ YAG crystal.

10. The solid-state laser according to claim 2, characterized in that: There are three Nd:YAG lath crystals and two YAG lath crystals.

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