CZ37302U1 - A solid-state Q-switched laser system and a laser instrument - Google Patents

Description

In the registration procedure, the Industrial Property Office does not determine whether the subject of the utility model meets the conditions of eligibility for protection according to § 1 of Act. E. 478/1992 Coll.

Solid-state Q-switched laser system and laser instrument

Field of technology

The presented technical solution concerns a solid-state laser system suitable for use in laser-stimulated plasma spectroscopy and laser cleaning of material surfaces. The presented technical solution mainly concerns the construction of this laser system, which is a Q-switched laser system, while the cooling of this system is ensured by the surrounding atmosphere, so-called passive cooling.

In another embodiment, the presented technical solution relates to a laser device containing the solid-state Q-switched laser system mentioned above.

Current state of the art

Analytical methods for the characterization of materials are necessary in various manufacturing processes. In addition, advanced sensors are currently being developed that examine material composition in real time and in-situ. Laser-Induced Breakdown Spectroscopy (LIBS) is one of the most important methods for characterizing materials. This method allows material (elemental) analysis to be performed in real time and in-situ.

LIBS instruments inherently require pulsed laser radiation sources with high peak power. Price, size, reliability, stability and the laser parameters themselves are then the determining parameters for usability in practice. Among all types of lasers, solid-state lasers have long appeared to be the most favorable candidate for use in LIBS. These lasers contain a solid-state active environment, especially specially grown crystals with different doping of active ions (e.g. Nd:YAG).

A laser with sufficient power and pulse energy can also reach the ablation threshold of many materials. Thanks to this, it is used in the field of laser cleaning of some materials, especially metals. Since the radiation is absorbed much better in the impurity materials than the metal itself, it is possible to achieve selective removal of the impurity itself without damaging the substrate if the beam size is chosen correctly. Compared to traditional methods, laser cleaning has many advantages, especially higher selectivity, accuracy and does not require any cleaning substances, which are often toxic or corrosive.

The Nd:YAG crystal is capable of generating laser radiation at a wavelength of 1064 nm. The laser with this active environment is then operated in the active electro-optical Q-switching mode, which guarantees the generation of nanosecond pulses with high peak power and enables time synchronization of the system with other elements of the LIBS analytical setup. Pumping this crystal can be done with discharge lamps. However, with the rapid development of the semiconductor industry, there is a transition to pumping the crystal using laser diodes. This guarantees the lasers higher energy efficiency, stability and lifetime. However, diode pumping is usually more financially demanding, as it requires more complicated optical systems and a mechanical system solution. Diode pumping is typically mediated by a laser stack containing a plurality of laser diodes placed therein. However, a stack of laser diodes emits a highly divergent and inhomogeneous pump beam, which should be adjusted before entering the crystal. The laser diode emits a beam of coherent light that spreads unevenly in two axes: the fast axis (Fast Axis) and the slow axis (Slow Axis). The fast axis determines the direction in which the light is most concentrated. The fast axis beam is quickly scattered away from the laser diode. The slow axis determines the direction, with the optical beam diffusing more slowly than the fast axis beam. According to the current state of the art, laser systems overcome the inhomogeneity of the pumping beam with the help of a homogenizer or a combination of a cylindrical lens and a lens homogenizer (so-called "lens duct" in English). However, this solution

- 1 CZ 37302 U1 cannot eliminate the structure of the pumping beam and thus causes a worse quality of the generated laser beam.

With regard to the above-mentioned requirements of the industry, the aim of the presented technical solution is to create a solid-state diode-pumped Q-switched laser system suitable for use in laser-stimulated plasma spectroscopy and laser cleaning of material surfaces. Another goal of the presented technical solution is to create this laser system which is compact and which can be cooled by the surrounding atmosphere without the need to use cooling liquids such as water.

The essence of the technical solution

The above-mentioned goals are at least partially achieved by the presented technical solution. The first embodiment of the presented technical solution represents a solid-state Q-switched laser system.

A solid-state Q-switched laser system includes a stack of pump diodes. The reservoir is equipped with diodes that emit optical radiation and provide a source for pumping the active environment of the laser resonator. The diodes are designed for quasi-continuous operation. Quasi-continuous operation of the laser has the property that the pump diodes are switched on only for certain time intervals, which are short compared to the total operation time of the diodes. However, the operation of the pump diodes lasts so long that the process of amplification and emission approaches its steady state, i.e. the state when the laser radiation is optically in the state of a continuous wave. The use of a quasi-continuous diode ensures a more efficient use of the input energy and reduces the amount of heat input to the system. The reservoir of pumping diodes dissipates its heat into the mechanical structure, which is subsequently cooled, preferably by thermoelectric coolers. The solid-state Q-switched laser system also includes a collimator for collimating the pump beam from the diodes into the active medium. The active medium in the laser system according to the presented technical solution is a crystal. Examples of these crystals include the chromium-doped synthetic alumina crystal GrALO'; aluminium-garnet with neodymium doping Nd:YAG; yttrium-vanadate with neodymium doping Nd:YVO4, preferably Nd:YAG. The laser system according to this technical solution also contains a Q-switch, which further contains a polarizing cube, a quarter-wave plate and an electro-optical modulator, preferably a Pockels cell. These optical elements modulate the internal losses of the resonator. The polarizing cube is placed behind the active medium crystal; and the quarter-wave plate is placed behind the polarizing cube; and the electro-optical modulator is located behind the quarter-wave plate. The output mirror of the laser resonator is also located behind the electro-optical modulator.

The essence of the technical solution is that the collimator is a slow axis collimator. The slow axis collimator is located immediately behind the pump diode stack, being offset from this position so that its focus does not lie on the surface of the pump diode emitting zone. The laser system according to the presented technical solution further includes a homogenizer located between the collimator and the crystal of the active medium. The homogenizer is shaped like a tapering truncated prism. Alternatively, the homogenizer is in the shape of a tapering truncated body, with the face for the input of the pumping beam from the collimator being a quadrilateral and the face for the exit of the pumping beam from the homogenizer being circular. The pump diode stack and crystal are cooled by thermoelectric coolers to dissipate waste heat through the base plate. The motherboard is also cooled by additional thermoelectric coolers, preferably with fins.

The laser system further advantageously contains control electronics for overall control and communication between other modules, especially a high-voltage module for Q-switching, a module for controlling the pump diode current and a thermoelectric cooling module for temperature regulation on the crystal and pump diodes. The control unit provides power distribution, communication via the RS485 bus and protection by disconnection in the event of possible malfunctions or user inputs using an interlock.

- 2 CZ 37302 U1

The laser system according to the presented technical solution can be thermally regulated using a passive metal cooler with a fan. Heat removal from the entire laser system is directed to the bottom of the system with coolers. Beneath the main box of the device is advantageously placed the fins of the coolers, which are used for effective heat dissipation. Together, these elements create a compact unit that autonomously ensures optimal thermal stability of the device. In addition, the laser system according to the presented technical solution can be made as a compact, robust, easily adjustable and maintainable device. The laser system is capable of generating nanosecond pulses with energy in the order of tens of millijoules.

In a preferred embodiment, the crystal of the active medium is longitudinally segmented. Each crystal segment contains a different level of active ion doping. In this preferred embodiment, the crystal is pumped longitudinally. This advantageous design absorbs pumping radiation more evenly and can reduce the influence of thermomechanical and thermo-optical phenomena.

Another preferred embodiment is a solid-state Q-switched laser system generating nanosecond pulses with energy up to 60 mJ.

In another preferred embodiment, the solid-state active medium is a Nd:YAG crystal.

In another preferred embodiment, the solid-state active medium is a cylindrical crystal.

In another preferred embodiment, the crystal of the active medium contains a dichroic layer applied to the face of the crystal, this layer being adjacent to the homogenizer and being a dichroic layer reflecting optical radiation with a wavelength of 1064 nm back into the crystal and transmitting radiation with a wavelength of 808 nm. In another advantageous embodiment, the crystal of the active environment contains an anti-reflection layer applied to the face of the crystal for the emission of laser radiation, the anti-reflection layer transmitting laser radiation with a wavelength of 1064 nm.

In another preferred embodiment, the face of the crystal of the active medium is flat, and this face is adjacent to the homogenizer.

In an alternative preferred embodiment, the face of the crystal of the active medium is curved, this face being adjacent to the homogenizer. The curvature can be both convex and concave.

In another advantageous embodiment, the output mirror of the laser resonator is curved. However, the curvature is chosen so that the laser resonator is a stable laser resonator. A stable laser resonator is a configuration in which the output mirror has a size of the radius of curvature adjusted to satisfy the condition for the stability of the resonator. The optical beam inside the resonator does not leak out of the laser resonator. According to this preferred embodiment, the resonator operates in multimode mode and the laser output beam has a super-Gaussian profile at the exit of the resonator.

In another preferred embodiment, the laser resonator is an unstable laser resonator in the positive branch. This unstable resonator contains an optical lens to compensate for the temperature lens of the crystal. The optical lens is located between the crystal and the Q-switch. In this preferred embodiment, the output mirror is curved.

In another advantageous embodiment, the output mirror of the laser resonator is a mirror with variable reflectivity. Instead of a partially reflective exit mirror, it is possible to advantageously use a mirror with variable reflectivity (GRM - Graded Reflectivity Mirror), which serves as a soft aperture and reduces diffraction effects. A variable reflectance mirror is a mirror that exhibits spatial variation in its reflectance. Preferably, a mirror with radially symmetrical variable reflectivity is used, i.e. reflectivity depending only on the distance from the center of the mirror. As a result, the beam at the focus can be smaller, which is advantageous for applications in LIBS devices. In another advantageous embodiment, the input and output face of the homogenizer is equipped with an anti-reflective layer for optical radiation at a wavelength of 808 nm.

- 3 CZ 37302 U1

In another preferred embodiment, the laser beam is directed by a pair of mirrors through a telescope to adjust the radius and divergence of the super-Gaussian output beam.

In another advantageous embodiment, the main box also contains a pair of mirrors and a telescope for directing the output of the laser beam.

The second embodiment of the presented technical solution represents a laser device containing a solid-state Q-switched laser system according to the first embodiment. The laser device is preferably placed in a fixed mechanical structure for stabilization, while the resulting structure of the laser device consists of two boxes made of thermally conductive material, preferably aluminum or its alloy. The laser device consists of a main box containing a solid-state Q-switched laser system and an electrical box. The main box and electrical box are separate from each other. The main box and electric box are equipped with passive coolers, even more preferably passive coolers and a fan for cooling. Passive coolers can be even more advantageously equipped with fins. The main box and the electrical box are preferably cooled by the air flow provided by the fan.

The individual components located in the main box and electrical box can thus be easily replaced using common tools. The electrical box provides protection and ensures the correct placement of electrical components and electronics. Its construction is designed with electrical insulation and efficient heat dissipation in mind. The internal layout is optimized for easy assembly and connection of electrical components.

In another preferred embodiment, the base plate contains a thermoelectric cooler with fins cooling the crystal.

Temperature stabilization of the pump diode and crystal is ensured by a system of thermoelectric cells. Heat removal from the entire assembly is directed to the bottom of the device, where the other radiator cells are located. Beneath the main box and the electrical box, there are fins for heat sinks, which are used for effective heat dissipation. Together, these elements create a compact unit that autonomously ensures optimal thermal stability of the laser device. Therefore, there is no need to connect the laser device to a separate water cooler.

In another advantageous embodiment, the laser device includes an electrical box connector panel for supplying power connected to the control unit; wherein the control unit is connected to a fan for removing heat from the space and a current source for switching diodes and a high-voltage source, which is further connected to a high-voltage switch, and a regulator of a thermoelectric cooler, wherein the current source is connected by diodes through a grommet for power cables; and wherein the thermoelectric cooler controller is connected to the motherboard thermoelectric cooler via a cable gland; and wherein the high voltage switch is connected to the electro-optical modulator via a grommet for high voltage cables.

In another advantageous embodiment, the current source for switching diodes, the regulator of thermoelectric cells, the high-voltage switch and the high-voltage source are connected, controlled and powered from the control unit, while the communication between them takes place using the RS485 serial communication bus.

Clarification of drawings

Giant. 1 is a schematic representation of the optical system of a laser device comprising a main box and an electrical box, wherein the main box contains a solid-state Q-switched laser with a marked laser beam path according to the presented technical solution.

Giant. 2 represents a graph of the dependence of the output energy of the Nd:YAG solid-state Q-switched laser system according to the presented technical solution on the current passing through the diodes.

- 4 CZ 37302 U1

Examples of implementing a technical solution

The following implementation examples serve for a more detailed understanding of the presented technical solution. The embodiments below represent preferred embodiments of the technical solution and combine the essential and advantageous features of the solid-state Q-switched laser according to this technical solution and the laser device according to this technical solution. Advantageous features are listed in the essence of the technical solution. The scope of protection is determined by the claims for protection, especially claim 1.

According to the following implementation examples, it is possible to achieve a solid-state Q-switched laser system with the parameters listed in Table 1.

Table 1 - Desired Achieved Laser Parameters _____Parameter________________________________Value

Pulse energy >50 mJ

Repetition frequency 50 Hz

Divergence <1 mrad

Pulse length <10 ns

Bundle quality M ² < 2

Fig. 1 shows an example of the realization of a laser device containing a solid-state Q-switched laser system according to the presented technical solution. The solid-state Q-switched laser system includes an active medium module 1 that includes an Nd:YAG crystal 14, a stack of pump diodes with a slow-axis collimator 11 with an output wavelength of 808 nm, which is located on a thermoelectric cooler 12. The slow-axis collimator 11 is located immediately behind the stack of pump diodes. The focus of the collimator 11 of the slow axis does not lie on the surface of the pumping diodes. Typically, the distance between the surface of the pump diodes and the collimator 11 of the slow axis is from 50 μm to 200 μm. The radiation from the laser diodes is captured by the homogenizer 13, which is made of optical-quality glass and has the shape of a four-sided prism with a truncated tip and edges. The input and output walls of the homogenizer 13 are equipped with an anti-reflection layer for the passage of optical radiation with a wavelength of 808 nm. The transmittance of pumping radiation through the homogenizer 13 is around 80%. At a distance of 200 μm from the homogenizer 13, a YAG crystal 14 with a length of 40 mm and a diameter of 4 mm is placed, which consists of a short undoped segment and a longer segment with Nd doping of 0.4%. The use of the undoped segment improves heat removal from the front side of the crystal 14, where it heats up the most, and additionally reduces the effects of mechanical stress and deformation of the faces, which are caused by the thermal expansion of the crystal 14. On the side of the crystal 14 of the undoped segment, it is equipped with a dichroic layer 141, which is highly -reflective for optical radiation with a wavelength of 1064 nm and anti-reflective for optical radiation with a wavelength of 808 nm. The active medium crystal 14 has a cylindrical surface and is sandblasted to suppress enhanced spontaneous emission and other parasitic optical phenomena. The crystal 14 of the active medium can be wrapped with an indium foil with a thickness of 100 μm, placed in a copper holder and cooled by a thermoelectric cooler 142 of the crystal 14. A steel aperture 2 with a diameter of 4 mm is placed approximately 1 cm behind the crystal 14. This prevents damage to crystal 14 by melting indium caused by parasitic reflection from one of the other elements.

The modulation of the resonator losses is mediated by the Q-switch 3. It consists of a polarizing cube 31, a quarter-wave plate 32 and a Pockels cell 33. The Pockels cell 33 is placed in a holder that allows you to set the orientation of its optical axis. The quarter-wave plate 32 is set to rotate the polarization of the laser beam by 90° during a double pass.

The resonator is terminated by a spherical output mirror 4 with a reflectivity of 70% located in a kinematic holder. The total length of the resonator is 20 cm and the radii of the output mirrors 4 are chosen so that the resonator is stable and the diameter of the fundamental mode is approximately 2 mm after taking into account the effect of the thermal lens. The output mirror 4 is set to be plane-parallel

- 5 CZ 37302 U1 with the output end of the Nd:YAG crystal 14. The optical axis of the Pockels cell 33 is oriented parallel to the axis of the output mirror 4. The output beam is directed by a pair of 5 mirrors located on kinematic holders, thereby ensuring horizontal operation of the output beam. A telescope 6 is used for possible collimation and adaptation of the size of the output beam. The laser beam is taken out of the device through the window 71.

For the generation of the output laser pulse, a 250 μs long pulse is first generated by the pump diode, using the current source 9 for switching the diodes. Approximately 10 μs after the end of the pump pulse, a quarter-wave voltage is applied to the Pockles cell 33. The quarter-wave voltage is generated by a high-voltage source 17 and is closed by a switch 16 with a rising edge of <10ns. This will sharply reduce the losses inside the laser resonator and, thanks to the high amount of energy stored inside the crystal 14 of the active medium, the generation of a nanosecond pulse will occur. In this case, the pulse repetition frequency is 50 Hz, the length of the laser pulse is approximately 7 ns, and the pulse energy is up to 60 mJ.

In another implementation example, the radii of curvature of the layer 141 were chosen to be 5000 mm (convex) and of the output mirror 4 to 4400 mm (concave) so that the resonator, after accounting for the thermal lens, was a laser resonator in the positive branch of the unstable zone. In addition, the length of the resonator was precisely adjusted to make the resonator confocal. This has the advantage that the output beam is collimated, has an approximately Gaussian profile in the near zone, and has better focusability. Furthermore, thanks to better collimation, depolarization losses inside the Pockles cell are reduced, which slightly increases the achievable pulse energy.

In another exemplary embodiment, pumping the Nd:YAG crystal 14 with quasi-continuous diodes in pulses of microsecond duration, eg 150 μs, to milliseconds, eg 2 ms, may take. These light pulses are collimated and homogenized by the aforementioned slow axis collimator 11 and homogenizer 13. Fig. 2 also shows a graph of the dependence of the output energy on the current flowing through the laser diodes verified in the laboratory of the HiLASE Center. The Q-switching of the laser system according to the presented technical solution was tested, showing the ability of the system to generate nanosecond laser pulses at an energy of 60 mJ at a repetition rate of 50 Hz.

In another embodiment, the output mirror 4 is replaced by a variable reflectivity mirror (GRM) with the same radius of curvature and with parameters such that the mirror serves as a soft aperture 2 for the fundamental mode. This guarantees the generation of the fundamental mode, but at the cost of reducing the output power. Diffraction effects are reduced with this approach compared to using a conventional aperture of 2.

The entire solid-state Q-switched laser system is placed on a metal base plate, which ensures the mechanical stability of the entire laser. The metal base plate is placed inside the aluminum alloy main box 7 with an internal cavity milled to an accuracy of +/- 0.05 mm. Individual parts are placed on metal pegs. The entire module 1 of the active environment, containing the beam homogenizer 13 and the Nd:YAG crystal 14, can be replaced as a complete part. The homogenizer 13 of the beam is also positionally adjustable with respect to the crystal 14 for efficient binding of light to the crystal. The chamber containing the laser resonator is hermetically sealed. The atmosphere inside the chamber with the laser resonator consists of air or nitrogen.

The laser device according to the presented technical solution includes a solid-state Q-switched laser system connected to electrical and electronic parts that are located in the electrical box 8. The electrical connection between the main box 7 and the electrical box 8 is conducted through a grommet 83 for high-voltage cables, a grommet 84 for cables and a grommet 85 for power cables. Thanks to this, the stability of the output parameters is further increased and a longer lifetime of the laser is ensured. The box for the electrical and electronic equipment of the laser device is also made of aluminum alloy. The outer dimensions of the laser device can be 350x103x92 mm. The top and bottom plates can be 5 mm thick, the side walls can be made of 2 mm thick sheets. 8 distance posts can be used to secure the position of electrical components and also as cover holders. The internal arrangement of the box serves for the vertical assembly of electronic printed circuit boards for individual electronic modules

- 6 CZ 37302 U1 system. Effective cooling can be provided by an 80x80 mm fan with an air flow of 30 l/s or more. The control elements and the connector panel 82 can be located on the front of the electrical box 8. The power wires passing through the common side wall to the electrical box 8 of the laser device can be wrapped with insulating elements.

The electronics of the laser are designed in such a way that all electrical and electronic components are located in the electrical box 8 next to the main box 7. This reduces the risk associated with cable routing to only the supply of 24 V amplitude and the supply of control signals for interlock and emergency stop, timing (trigger) and the communication interface itself. Control of the laser is provided by the control unit 10, which distributes power and is connected to the control and communication bus to other electronic modules of the system. These modules are mainly a current source 9 with a peak power of >5500 W for switching diodes, a high-voltage source 17 with an adjustable amplitude in the range of 2200 to 5500 V, which is further connected to a high-voltage switch 16 with a fast rising edge of <10 ns. Furthermore, the control unit 10 is connected to the regulator 15 of the thermoelectric cooler 72, while the current source 9 is connected to the diodes through the grommet 85 for power cables; and wherein the thermoelectric cooler controller 15 is connected to the motherboard thermoelectric cooler 72 via a cable grommet 84; and wherein the high voltage switch 16 is connected to the electro-optical modulator via a grommet 83 for high voltage cables.

Communication between individual modules is ensured by a protocol that is transmitted through the RS485 serial bus. Part of the control unit is safety supervision implemented through an interlock and temperature sensing on crystal 14, a pumping diode. In the event of an evaluation of a dangerous condition, the laser immediately stops its operation.

Temperature stabilization of the pump diode and active crystal 14 is provided by a system of thermoelectric cells, the location of which was chosen based on numerical simulations of the heat dissipation of the entire assembly so that the location enables heat dissipation as efficiently as possible. Heat removal from the entire assembly is directed to the bottom of the device, where additional thermoelectric coolers 72 of the base plate are located. Beneath the case of the device is placed the ribbing of the base plate coolers 72, which are used for effective heat dissipation. Together, these elements create a compact unit that autonomously ensures optimal thermal stability of the device. Therefore, there is no need to connect the laser to a separate water cooler 72 of the base plate. The electric box 8 is cooled by air flow provided by a suitably located fan 81.

The cabinet is fixed using spring-loaded brackets that are screwed directly onto the cabinet body. This design allows for easy assembly and ensures a firm and stable attachment of the cabinet. The sprung mounts also provide protection against vibration.

Industrial applicability

The presented technical solution is mainly used in the design of a laser for the spectroscopy of laser-excited plasma or for laser cleaning.

Claims (17)

1 Module with an active environment 1. A solid-state Q-switched laser system comprising • a pump diode stack comprising diodes for pumping the active medium of the laser resonator, the diodes being quasi-continuous and steady-state; and wherein the stack of pump diodes is cooled; and • a collimator for collimating the pumping beam from the diodes into the active environment; where • the active environment is a crystal (14); and • Q-switch (3) containing a polarizing cube (31), a quarter-wave plate (32) and an electro-optical modulator for modulating the internal losses of the resonator, the polarizing cube (31) being placed behind the crystal (14); and the quarter-wave plate (32) is located behind the polarizing cube (31) and the electro-optical modulator is located behind the quarter-wave plate (32); and • the output mirror (4) of the laser resonator located behind the electro-optical modulator, characterized in that • the collimator is a slow-axis collimator (11) located immediately behind the stack of pump diodes, while the focal point of the collimator does not lie on the surface of the pump diodes; and wherein the system further comprises • a homogenizer (13) located between the collimator (11) and the crystal (14), wherein • the homogenizer (13) is in the form of — a tapering truncated prism, or — a tapering truncated body, while the face for the input of the pumping beam from the collimator (11) is a quadrilateral, and the face for the outlet of the homogenizer pump bundle (13) is circular; and wherein • the pump diode stack and crystal (14) are cooled by thermoelectric cells (12 and 142) to dissipate waste heat through the base plate; while • the base plate is cooled by thermoelectric coolers (72) of the base plate. 2 Aperture 2. A solid-state Q-switched laser system according to claim 1, characterized in that the crystal (14) is a longitudinally segmented crystal (14), each segment of the crystal (14) containing a different level of active ion doping; and wherein the crystal (14) is longitudinally pumped. 3 Q-switch 31 Polarization Cube 32 Quarter-wave plate 33 Pockels cell 3. A solid-state Q-switched laser system according to any one of the preceding claims, characterized in that it produces nanosecond pulses with an energy of up to 60 mJ. 4 Output mirror 4. A solid-state Q-switched laser system according to any one of the preceding claims, characterized in that the crystal (14) of the active medium is Nd:YAG. 5 A pair of mirrors to direct the output beam 5. A solid-state Q-switched laser system according to any one of the preceding claims, characterized in that the crystal (14) of the active medium is cylindrical in shape. 6 Telescope 6. A solid-state Q-switched laser system according to any one of the preceding claims, characterized in that the crystal (14) of the active medium contains a dichroic layer (141) deposited on the face of the crystal (14) adjacent to the homogenizer (13), wherein the dichroic layer (141) 7 Main box 71 Output window 72 Thermoelectric motherboard coolers 7. A solid-state Q-switched laser system according to any one of the preceding claims, characterized in that the crystal (14) of the active medium contains an anti-reflection layer deposited on the face of the crystal (14) for the emission of laser radiation, the anti-reflection layer transmitting laser radiation with a wavelength of 1064 n.m. 8 Electric box 81 Fan 82 Connector panel 83 Grommet for high voltage cables 84 Grommet for cables 85 Grommet for power cables 8. A solid-state Q-switched laser system according to any one of the preceding claims, characterized in that the face of the crystal (14) of the active medium is flat, this face being adjacent to the homogenizer (13). - 8 CZ 37302 U1 reflects optical radiation with a wavelength of 1064 nm back to the crystal (14) and transmits radiation with a wavelength of 808 nm. 9 Current source for switching diodes - 9 CZ 37302 U1 20. A laser device according to any one of claims 16 to 19, characterized in that the electrical box (8) contains a connector panel (82) for supplying power connected to the control unit (10); while the control unit (10) is connected to a fan (81) for removing heat from the space and a current source (9) for switching diodes and a high-voltage source (17), which is further connected to a high-voltage 5 switch (16) and a regulator (15 ) of a thermoelectric cooler (72), the current source (9) being connected to the diodes via a grommet (85) for power cables; and wherein the thermoelectric cooler controller (15) is connected to the motherboard thermoelectric cooler (72) via a cable grommet (84); and wherein the high voltage switch (16) is connected to the electro-optical modulator via a grommet (83) for high voltage cables. 9. A solid-state Q-switched laser system according to any one of claims 1 to 7, characterized in that the face of the crystal (14) of the active medium is curved, this face being adjacent to the homogenizer (13). 10 Control electronics 10 21. Laser device according to any one of claims 16 to 20, characterized in that the current source (9) for switching diodes, the regulator (15) of thermoelectric cells, the high-voltage switch (16) and the high-voltage source (17) are connected, controlled and powered from the control unit (10), while the communication between them is realized using the RS485 serial communication bus. 10. A solid-state Q-switched laser system according to any one of the preceding claims, characterized in that the output mirror (4) of the laser resonator is curved, and wherein the laser resonator is a stable laser resonator. 11 Slow axis collimator 11. A solid-state Q-switched laser system according to any one of claims 1 to 9, characterized in that the laser resonator is an unstable laser resonator in the positive branch containing an optical lens compensating the temperature lens of the crystal (14), the optical lens being placed between the crystal (14 ) and Q switch (3); and wherein the output mirror (4) is curved. 12 Thermoelectric cooler 12. A solid-state Q-switched laser system according to any one of the preceding claims, characterized in that the output mirror (4) of the laser resonator is a mirror with variable reflectivity. 13 Bundle homogenizer 13. A solid-state Q-switched laser system according to any one of the preceding claims, characterized in that the input and output face of the homogenizer (13) is provided with an anti-reflective layer for optical radiation at a wavelength of 808 nm. 14 Crystal 141 Dichroic layer, HR for 1064 nm, AR for 808 nm 142 Thermoelectric crystal cooler 14. A solid-state Q-switched laser system according to any one of the preceding claims, characterized in that the laser beam is directed by means of a pair (5) of mirrors through a telescope (6) to adjust the radius and divergence of the super-Gaussian output beam. 15 Regulator of thermoelectric cells 15 2 drawings List of relationship tags: 15. Solid-state Q-switched laser system according to claim 14, characterized in that the main box (7) further contains a pair (5) of mirrors and a telescope (6) for directing the output of the laser beam. 16 High voltage switch 16. A laser device, characterized in that it comprises a solid-state Q-switched laser system according to any one of the preceding claims, wherein the laser device is housed in a fixed mechanical structure for stabilization, the structure consisting of a main box (7) containing a solid-state Q-switched laser system; and from the electrical box (8), whereby the main box (7) and the electrical box (8) are separated from each other. 17. Laser device according to claim 16, characterized in that the main box (7) and/or the electrical box (8) is/are provided with a passive cooler (12 and 142) with a fan and the electrical box (8) ) is also equipped with a fan for cooling. 18. Laser device according to claim 16 or 17, characterized in that the passive cooler of the main box (7) and/or electrical box (8) is equipped with fins. 19. Laser device according to any one of claims 16 to 18, characterized in that the base plate contains a thermoelectric cooler (142) of the crystal (14) with fins. 17 High voltage source