RU2525578C2 - Method of outputting and controlling energy/power of output laser radiation and apparatus therefor - Google Patents

Abstract

FIELD: physics, optics.

SUBSTANCE: invention relates to laser engineering. The method of outputting and controlling energy/power of output laser radiation includes mounting a reflecting element in a laser resonator at an angle to its axis, said reflecting element being mounted on a movable base, the position of which determines the level of the output energy/power after turning on the laser and setting the required level of pumping energy/power. In the resonator of a pulsed or continuous laser between the output mirror of the laser, which is replaced with an opaque reflecting mirror, and the end of its active element as a reflecting control element, an opaque reflecting mirror is mounted on a movable base which enables to move said mirror parallel to its reflecting surface in the range from its full exit from the light field established in the resonator to complete overlapping of said field after entrance of said movable mirror, with the possibility of not only outputting laser energy/power, but control thereof, and particularly gradual change of energy/power from zero to a maximum value and vice versa at a given pumping level and setting the output energy at the required level.

EFFECT: providing a stable spatial position of an output laser beam.

2 cl, 16 dwg

Description

The claimed technical solution relates to methods for controlled output of radiation from a laser cavity. The claimed method relates to methods and devices for outputting energy (pulsed) and power (continuous) lasers with resonators, between the output mirror and the active element of which there is some space.

The claimed method cannot be used in cases where the coatings of the mirrors of the resonators are applied directly to the ends of the active elements of the lasers, or in lasers having other similar solutions, i.e. when the resonators are one with the active elements (miniature laser devices). The claimed technical solution also does not apply to cases where the regulation of the output power of the lasers is provided by various electronic methods - for example, by controlling (changing) the energy / power of the pump source.

The claimed technical solution can be used to create any types of lasers that have a resonator, the mirrors of which are structurally separated from the active element. Moreover, this technical solution can be used in lasers of various types: lasers operating at a fixed frequency, tunable lasers, ultrashort pulse lasers, laser photometers and spectrometers. The claimed method can be applied in lasers that operate in various spectral ranges, including: medium infrared, infrared, visible, ultraviolet, vacuum-ultraviolet and soft x-rays.

Attempts to control the output energy / power in order to achieve the maximum at the selected level of pumping quickly and simply have been ineffective so far. The technical solutions of the regulation methods announced earlier, sometimes laborious and expensive, did not solve this problem to the full, and also these solutions often had highly specialized fields of application. In addition, devices implementing these solutions were structurally complex and technologically challenging.

The claimed technical solution consists in replacing the output (translucent) mirror of the laser resonator with a mirror with a reflection close to 100%, and introducing an additional movable output opaque mirror into the resonator, with which the optical energy / laser power is output. This output mirror is mounted to the axis of the resonator, in the general case, at an angle so that the radiation reflected from it is freely removed from the resonator without touching the elements and components of the laser. The output mirror itself is mounted on a special device that allows you to precisely, reciprocally move this mirror in the plane of its reflective surface.

When pumping the active medium of the laser, a standing light wave is established in its cavity. When moving the output mirror using a special device in the direction to the axis of the resonator from a certain position, the output mirror begins to partially overlap the field of this wave. This part of the blocked light wave is reflected from the surface of the mirror and is removed from the resonator as useful radiation. The part of the standing wave energy remaining inside the laser cavity is used for self-support. With further movement of the mirror in the same direction, the output energy / power of the useful radiation will first increase to a maximum, and with a further movement, decrease. Further, when a certain position of the output mirror is reached, when the energy / power of the standing wave remaining in the laser cavity is insufficient for self-maintenance, the generation of radiation breaks down.

Thus, the claimed method provides the possibility of a smoothly controlled output of energy / power from the laser cavity without turning off the laser itself. Using the inventive method for the selected level of energy / pump power of the laser using the device allows you to find the position of the output mirror at which the level of output energy / laser power will be maximum. Thus, the purpose of the device is to control the power / energy of the laser in order to:

1. finding and setting the maximum level of output laser energy / radiation power, at the selected pump level, promptly without turning it off;

2. Regulation of the energy level / laser radiation power in order to set the level necessary for the consumer in the range from minimum to maximum achievable under the conditions of paragraph 1.

When adjusting the output energy / laser power of the claimed method, the position of the spot of the laser beam on the target does not experience any displacement.

The applicant has analyzed the prior art at the filing date of the application and identified analogues of technical solutions that are directly related to the claimed technical solution in relation to both known methods and devices. Below, the applicant provides information on the identified methods of regulating the energy / power of the lasers and devices that implement them.

The problem of simply controlling the output energy / power of the lasers has been relevant since the creation of the lasers themselves.

The problem of creating a method and device that allows you to smoothly adjust the output power of the laser without turning it off is the most relevant and not resolved to date due to the presence of objective technical issues that are not fully resolved, as described, for example, in the following descriptions of inventions and patents.

Known technical solution (analogue 1) according to the patent US 3448404 from 1969, (H01S 3/05, Filed Dec. 22, 1965, Ser. No. 515, 791 Int Cl. H01S 3/05 US Cl. 331-94.5), claimed by Rose A. McFarlane et al. A method has been proposed for controlling the output power of a gas laser using a transparent plate 21 and a mirror 22 (FIG. 1). This method is based on the known dependence of the transmission / reflection of a transparent plate on the angle of incidence of radiation on it. In this method, the plate 21 is initially installed at a Brewster angle (parallel to the plates 12 and 13, they are the windows of the gas cell of the active element of the laser, and which are also installed on it at the Brewster angle). In this position of the plate 21, the radiation generated by the laser passes without loss. When this plate deviates from the Brewster angle, part of the radiation begins to be reflected from it (part of the power is taken from the generated radiation) and is directed by the mirror 22 to the absorber. Thus, at the laser output (mirror 16), the required radiation power level is selected. It should be noted that control of the laser output power by changing the pump power at that time was not possible due to the level of development of electronics at that time, and the need to control the laser output power was relevant even then (analogue 1).

The disadvantages of the known method and device are:

1. there is no way to find the maximum possible output power at the selected pump level due to the fact that the initial level of output power is determined by passing the output mirror (16) of the laser resonator, and in this method, ideologically and constructively, regulation is only set in the direction of decreasing (attenuation) from this initial output power level. And the reflection coefficient of this output mirror (16), which is optimal for one level of laser pumping, will not be optimal for another level of pumping;

2. applicable only to lasers operating in a narrow spectral region, due to the presence of structural elements that limit it, because this region is limited by the spectral transmission region of the transparent plate used in the laser cavity;

3. low accuracy of the retention of the laser beam spot on the target during regulation, which is a consequence of the design features of the device, because the spot of the laser beam on the target will experience displacement caused by the refraction of the beam in the control plate 21, which has a finite thickness. Moreover, this shift is greater, the larger the angle between the plane of the control plate and the axis of the resonator, and it also depends on the thickness of this plate;

4. a large number of optical elements and nodes for implementation in the device, which dramatically complicates the design, because for the implementation of the known device requires three additional elements: a transparent plate 21, a mirror 22 and an element that absorbs radiation, each with its own mechanical unit to hold them. Moreover, the angle between the plate 21 and the mirror 22 should be 90 degrees.

A known method (analogue 2) of the controlled output of radiation from the resonator, proposed in the work: “Eduardo Granados, David W. Coutts, and David J. Spence / Mode-locked deep ultraviolet Ce: LiCAF laser // OPTICS LETTERS / Vol.34, No .11 P.1660-1662. " In this work, a laser pumped laser is described, in which the useful part of the radiation is removed from the resonator using a transparent plate. Moreover, a smooth change in the output power of this laser for regulation is carried out by its rotation. Below in the description is presented a fragment from this article and a drawing with a diagram of this laser with a signature on it, as well as part of the text of the article, where its scheme is described. The applicant immediately provides the relevant translations into Russian.

In FIG. 2, the phrase related to the subject matter is marked in bold: “.... The three cavity mirrors had low transmission (<0.03%), and so a 6-mm-thick UV-grade silica plate placed in the cavity at close to Brewster's angle was used as a variable output coupler. The cavity lengths of the pump and cerium laser were matched for synchronous mode locking. Each time the chopper opened a stable mode-locked pulse train was produced after approximately 4 mks build up time. A maximum output of 52 mW was obtained, with an output coupling of 3% inferred by measurement of the coupler angle. All reflections from the plate were included in the power measurement; this power could be easily produced in a single output beam with a suitable transmissive cavity mirror. ... "Translation of the text:" ... Three resonator mirrors had low transmittance (<0.03%), and also a 6 mm thick wafer made of UV quartz placed in the resonator at an angle close to the Brewster angle was used as an output mirror with variable transmission. The length of the cavity for pumping the cerium laser was chosen to achieve mode locking. Each time the interrupter opened, a stable mode of the sequence of pulses generated after approximately 4 μs from the moment of its opening was established. The maximum power of 52 mW was obtained with an output coupling of the output from the resonator of about 3% (equivalent to an output mirror with a transmission of 3%), determined by a change in the angle of the coupler. All reflections from the plate were taken into account when measuring the output power; this power could easily be determined by a resonator with a single output beam with a mirror with equivalent transmission ... ”(analogue 2).

In the known method according to analogue 2, for regulating the output radiation as a physical principle, as well as in the analogue of regulation method 1, the dependence of the reflection coefficient of the transparent plate on the angle of incidence of radiation on it is used. Only in analogue 2 is the plate used to output useful radiation from the laser cavity, which is composed of their “deaf”, with a reflection equal to 100% of the mirrors. In this way, it is possible to smoothly control the output energy / power and during regulation, you can find a position of the plate at which the output energy / power of the laser with such a resonator will be maximum. However, in analogue 2, in accordance with the laws of optics, in the opposite direction from the direction of the output radiation indicated by the authors, the radiation will also be reflected on the opposite side of the plate, which will lead to additional losses. The last, very negative property of the analogue of 2 authors did not pay attention to the reader.

The disadvantages of the known method and device are:

1. narrow spectral range of its application due to the presence of structural elements that limit it, because this region is limited by the spectral transmission region of the used transparent plate;

2. the complexity of the regulation of the output power due to the features of the principle of operation of the device, because when regulating energy / power, the direction of the output radiation changes quite significantly, namely: the angle between the extreme positions of the output beam is tens of degrees. In this case, there is a need to move the "consumer" of the radiation of such a laser, for example, a target, and again direct the radiation to the same place where the radiation fell before the previous adjustment of the output energy / power;

3. low efficiency of the device due to the design of the device — the presence of reflection in the opposite direction to that shown in Figure 2 (not shown by the authors in the figure), this is a channel for additional losses, which reduces the efficiency (efficiency) of the laser as a whole;

4. the complexity of the construction of the known device due to the fact that for the device that implements this known method, in addition to the node for rotating the plate, with which the output energy / laser power is controlled, a special device will be needed to move the target, that is, the radiation receiver, which tracked would change the direction of the output laser beam.

A known method (analogue 3), in which to control the output energy / radiation power of the laser uses an interference mirror in the form of a wedge filter. This method is presented in US patent 4187475 dated February 5, 1980, claimed by Irwin Wieder (Irwin Wieder). (Int. Cl. H01S 3/08 U.S. Cl. 331 / 94.5 S; 331 / 94.5 C; 350/288). This wedge filter is an interference mirror in which the thicknesses of the layers of dielectric coatings vary from one edge of the mirror to the other. As a result, the transmission of such a mirror for a particular selected wavelength is a function of its position relative to the incident beam. This wedge filter is used as the output mirror of the laser cavity. Energy regulation is carried out by reciprocating movement of this mirror perpendicular to the axis of the resonator. By moving this output mirror, find its position at which the output of the laser output energy is maximum.

Figure 3 shows a wedge filter. Dielectric layers 4, 6, 8, 10, and 12 are applied to a glass or quartz substrate 2 sequentially with a large and a small dielectric constant so that the thickness of each layer increases linearly from one end of the substrate to the other. Thus, the transmission of such a filter for a selected wavelength will be a function of the position of the radiation beam relative to the edges of such a mirror (analogue 3).

The disadvantages of the known method and device are:

1. a narrow spectral range of application of this method, since it is limited by the transparency range of the base of the wedge filter, as well as the materials sprayed onto it;

2. sophisticated technology and high cost of applying dielectric coatings of variable thickness.

3. The complex design of the device, both in implementation and in use, since it performs two functions at once: the output mirror of the laser resonator and the control device. That is, in addition to the usual alignment screws required to configure this wedge filter as the output mirror of the laser resonator, this assembly must have a longitudinal displacement device, and it must be very precise, so that this alignment is preserved. Therefore, in the known method 3, when used for a wedge filter, automatic tuning with electronic control is used.

A known method (analogue 4), which allows you to adjust the output radiation of the laser through an additional intracavity device, is protected by patent US 3243724 from 1963, claimed by Arthur Wilstek (Arthur A. Vuylsteke). (U.S. Patents 3243724 1/1963 S.n. 250, 250 3 Claims (Cl.331-94.5)). The installation diagram implementing this method is shown in Fig.4. This method uses the division of intracavity circularly polarized laser light into ordinary and extraordinary waves by a birefringent crystal 20 introduced into the resonator, as well as a control element 18 introduced therein that can rotate the polarization of the radiation passing through it, for example, as a Kerr cell . By rotating the latter relative to the axis of the resonator, the radiation is regulated and, accordingly, the fraction of the output power of the laser radiation is changed.

The regulation principle is shown in Fig.4. As the active element of the laser, ruby 10 was used in the form of a cylindrical rod with plane-parallel ends 12 and 14, which were perpendicular to the axis of the rod. An end face 12 is coated with a reflection coefficient close to unity. This coating, together with the mirror 22, forms a “blank” (that is, both mirrors have 100% reflection at the generation wavelength) laser cavity. The butt 14 does not have a coating, therefore, all generated energy freely passes through it. The rod 10 is surrounded by a pulsed pump lamp made in the form of a spiral 16, which is connected to a power source 17. The output radiation beam is polarized perpendicular to the axis of the rod. In the path of a laser beam, i.e. coaxial to the rod, there is a polarization rotator 18, and behind it is a birefringent polarization selector 20, which divides the radiation beam into two - ordinary and extraordinary beams. An unusual beam emerges from the laser cavity as useful radiation, while an ordinary beam remains in it, reflected from mirror 22 to maintain a standing wave of laser generation.

The disadvantages of the known method and device are:

1. large losses of radiation on the surfaces and in the body of the additional elements 18 and 20 introduced into the resonator, which introduce additional losses in the latter, which negatively affects the output characteristics of the laser;

2. a narrow spectral range of application, which is limited by the spectral and optical characteristics of birefringent optical elements and elements for rotating the plane of polarization, in addition, polarization-active materials are known only for a narrow spectral region — visible and near infrared ranges;

3. the complex design of the device, which occupies a large intracavity space, because To implement the device, two optical elements are required, which are installed in the resonator one after another, each with its own alignment unit, while with the precision rotation of one of them.

A known method (analogue 5) for controlling the output power is described in the patent (RU 2150773, IPC H01S 3/08, application 98118589/28, 08.10.1998). For this, a stably-unstable resonator is used in a high-power laser (see Fig. 8), inside of which there is a “flat” extended active medium. A stable-unstable resonator having stability in a vertical plane (the resonator in this plane is shown on the lower part of Figure 5), and an instability plane is located perpendicular to it, in which the output power is controlled. A view of the resonator in this plane with the control device is shown on the upper part of FIG. 5. The output of radiation in the laser is carried out by reciprocating movement of the block of mirrors 4 along the direction of output. In the plane of instability, the resonator has a small magnification coefficient M, 1 <M <2. The technical result of the invention consists in the ability to control the level of output power with the possibility of finding its maximum level at a given pump level, which leads to an increase in the laser efficiency.

The disadvantages of the known method and device are:

1. low spatial coherence of the generated laser beam — it consists of two beams, so the angle between the mirrors in the block of mirrors must be kept equal to 90 degrees as accurately as possible, otherwise these halves of the beam will diverge at a great distance;

2. The resonator device is difficult to construct, because It requires precision units with adjustment both for each of the block mirrors and for moving the entire adjustment block.

A known method (analogue 6) output power / energy from the laser cavity. The essence of this method is described in the book: E.F. Ischenko, “OPEN OPTICAL RESONATORS SOME QUESTIONS OF THEORY AND CALCULATION”, MOSCOW: SOVIET RADIO. - 1980. On page 8 is shown Fig.1.2 (see Fig.6 of this application) with the following text: "... Sometimes use an element with a communication hole (Fig.1.2b); there may be several such holes. It is also possible to output radiation through the edges of one of the reflectors (Fig.1.2v) or using a translucent plate placed inside the cavity of the resonator (Fig.1.2g). "

The transmission of such a mirror, in turn, is determined by the transparency of the output mirror in Fig. 6 - Fig. 1.2a or by the ratio of the area of the hole in the output mirror to the area of the standing wave spot (in Fig. 1.2, the standing wave region is shaded) generated in the laser during generation - Fig.1.2b, or the area of a spot of a standing wave to the area of a mirror for the case 1.2c. It should be noted that in the cases shown in Fig.6 (Fig.1.2b and 1.2c), the radiation is output beyond the edges of the output mirrors. The size of a standing wave spot, in turn, is determined by the configuration of the resonator (with flat mirrors arranged confocal, concentrically, etc.). In the case of the resonator circuit shown in Fig. 6 (Fig. 1.2d), the level of output power / energy from the resonator is determined by the transparency (specularity) of the plate placed inside its cavity. We emphasize here that for the cases shown in Fig. 6 (Fig. 1.2a-c), each time the mirror is replaced, alignment of the resonator is required, and in the case shown in Fig. 6 (Fig. 1.2d), no adjustment required.

The disadvantages of the known method and device are:

1. the inability to quickly control the output power / energy without turning off the laser, because to change the ratio of the spot area of the emitted radiation to the area of the remaining part of the standing wave spot on the resonator mirror, a set of 3-5 mirrors with different hole diameters or a set of translucent plates with different transmittance (reflectivity) is required, for the case shown in Fig.6 ( fig. 1.2d);

2. the need for a new alignment of the resonator with each replacement of the mirror with a mirror with a different area ratio. But in the case shown in Fig.6 (Fig.1.2d), with translucent plates, alignment of the resonator is not required, however, for security reasons, the laser must be turned off to install a new plate and adjust its position in order to restore the direction of laser radiation to the target.

3. a large number of expensive mirrors for implementing the device according to any of the prototype schemes, because requires a set of 3-5 mirrors with different transmission (or a set of translucent plates) for each of the declared spectral ranges: medium infrared, infrared, visible, ultraviolet, vacuum-ultraviolet and soft x-rays, as well as the need for laser alignment when replacing one mirror to the other in all the ranges mentioned. In addition, to these inconveniences in the case of a laser operating, for example, in the vacuum-ultraviolet region of the spectrum, when replacing one mirror with another, the need for depressurization of the box in which this laser is placed is added, with evacuation of the box again after replacing the mirror, which ultimately leads to unreasonably high costs of material resources and time.

4. low efficiency due to reflection (loss) of part of the power / energy by the opposite side of the plate (not indicated by the author) in the direction opposite to the output radiation.

A device according to the invention "Laser", protected A. with. No. SU 884526, which implements a method for controlling the energy / power of the laser output radiation (prototype). The known device is distinguished by the fact that “the resonator in the proposed laser is formed by a roof-shaped and flat metal mirrors, between the active medium and a flat metal mirror there is a flat mirror diffraction screen made movable in a direction perpendicular to the optical axis and covering at least half of the aperture of the radiation beam, and the mirror surface of the screen faces the active medium and is parallel to the edge of the roof-shaped mirror.

Moreover, along the edge of the roof-shaped mirror, a slit of adjustable width is made "(Figs. 9, 10).

Common features between the compared solutions (prototype and the claimed solution) in relation to the method are:

- the output radiation of the laser cavity is output using the regulatory element;

- the regulatory element is arranged to move;

 regarding the device:

- output mirror with 100% reflection;

- a regulating element of the output radiation, placed between the active element and the output mirror;

- mechanism for moving the regulatory element.

Before describing the disadvantages of the known device and method, carried out using this device, implemented in the invention by AS, it should be noted that described in AS the laser and the control method apply only to pulsed lasers. Mention of the term “power” refers only to the peak power of the pulses, increasing due to the shortening of the duration of these pulses.

The disadvantages of the technical solution described in A.S. include:

- the operability of the method of output and regulation in lasers only pulse action;

- as a reflective element for output radiation output, which implements a method of energy and power output and regulation, a diffraction screen is used - a complex, expensive and not resistant to high radiation density element that is not considered as an independent regulatory element (since it works in conjunction with a roof-shaped mirror) and cannot be used in other types of lasers;

- the difficulty of installing a diffraction screen, the surface of which should be strictly parallel to the edge of the roof-shaped mirror;

- a small control range, since the control element is already inserted into the resonator field, by no less than half, and the task of this element is to compensate for energy losses by finding its maximum possible value (energy) after setting a different slot width in the roof-shaped resonator;

- losses at the edge of the screen and losses at the slit of the roof-shaped mirror, which lead to an increase in the generation threshold and a decrease in efficiency;

- the movement of the radiation spot on the target due to the movement of the control element and the presence of a diffraction fracture that changes when the control element is moved;

- to keep the radiation spot on the target, the need to use additional elements outside the laser structure;

- energy regulation is carried out by successive approximation, but not less than two stages: regulation of the slit of the roof-shaped mirror, adjustment of the output power with the help of a diffraction screen and the implementation of the duration control.

The claimed technical solution is illustrated by the following graphic materials:

Figure 1 presents the analogue of the US patent in the form of a three-dimensional image of a known device.

Figure 2 presents the analogue in the form of a diagram of the experimental setup with a schematic representation of a known device

Figure 3 presents the analogue of US patent in the form of a schematic representation of a known device.

Figure 4 presents the analogue of US patent in the form of a three-dimensional schematic image of a known device.

Figure 5 presents the analogue of the application for the invention in the form of a schematic representation of a known device.

Figure 6 presents an analogue from the book in the form of a schematic representation of a known device.

Figure 7 presents the analogue by AS selected as a prototype in the form of a schematic representation of a known device.

On Fig presents a diagram of a dye laser used in experiments.

Figure 9 presents a General view in the form of a schematic representation of the claimed method and device.

Figure 10 presents a detailed fragment of the claimed technical solution, an enlarged fragment of the circuit of the output part of the laser, shown in Figure 9.

The essence of the claimed technical solution lies in the method of regulating the energy / power of the output laser radiation, in which:

- the output mirror is replaced with a “deaf” one;

- an additional mirror is used, mounted in the resonator at an angle to its axis, on a device that provides smooth reciprocating movement of this mirror along its reflecting plane in order to smoothly control the energy / power of the laser output radiation.

Having made a significant simplification of the design, on the one hand, the authors managed to solve 11 problems, for the solution of which, by the methods of conventional design, it would be necessary to resolve practically insurmountable contradictions.

For example, to increase the efficiency for each pump level, you need to select an individual mirror. It should be noted that the number of steps for selecting mirrors for each pump level can be several (from 3-4 to tens).

The claimed technical solution provides an increase in the performance indicators of pulsed and cw lasers equipped with resonators in the form of separate mirrors, by elementary replacing the output mirror, usually used with a “blank” one, while using the claimed device with a mirror mounted in the resonator, 11 goals were achieved ( tasks), and this is a proof of non-obviousness for specialists in this field of technology.

This non-obviousness is proved by the fact that in this case there is a technical contradiction between the need to maintain the laser efficiency at the highest possible level at any pump levels. However, the output mirror of the resonator (for example, a pulsed or cw laser) with one reflection coefficient, which is optimal for one energy / pump power level, is not optimal for another level. Moreover, with an increase in the pump level, it is necessary for the laser to have an output mirror with a lower reflection coefficient, and with a decrease in the level, with a higher reflection coefficient.

Prior to the presentation of the claimed technical solution in most of the methods known from the prior art for the selected pump level, the regulation was carried out by selection, that is, by replacing one translucent mirror with another with a different transmittance, followed by its rearrangement. This action was a technically quite complicated procedure and quite an expensive process in the sense of the need for material costs for the acquisition, selection and adjustment of mirrors in lasers, while there was a strict need to turn off the laser. Thus, the main objective of the claimed technical solution is to realize the possibility of removing, regulating and maintaining the output energy / power at the level required by the user within the range provided by the selected level of laser pumping without turning it off.

When outputting and adjusting the output laser energy / power, the claimed technical solution ensures the stability of the spatial position of the output laser beam, which is a very significant (significant) factor determining the quality of controlled performance indicators and other significant indicators of the laser being developed (i.e., laser, in which the claimed method is implemented).

The basis of the claimed technical solution was the task of developing a method and device for outputting and controlling the level of optical energy / power output from the laser from the resonator (with the possibility of providing it (maximum level energy / power) of pulsed and / or continuous operation directly during its operation - without it stop and new alignment of the laser resonator.When using the claimed method due to the possibility of operational adjustment of the energy / power of the output radiation using the device, realizing about it, the efficiency of the laser can be maximally possible at any current level of pumping (since the transmission of the output mirror of the laser should be the greater, the higher the level of pumping, that is, it requires constant adjustment) .In the claimed embodiment, the design and dimensions of the laser, equipped with this device are not changed, and it can be built into almost any laser operating (used) in economic circulation, which has a free space between the output mirror and the active element something sufficient to install the inventive regulation device, through which the claimed method is implemented.

The claimed technical solution makes it possible to solve all of the listed disadvantages identified in the prior art for analogues and the closest analogue prototype through the use of a solution that is quite simple in terms of design and allows new lasers to be given a new quality (new consumer properties that are not currently known from the prior art of the device), namely:

1. providing the possibility of increasing the laser efficiency at the selected pump level;

2. providing the possibility of operational control of the output radiation at the current pump level directly during laser operation;

3. providing the ability to control the energy / laser power in the widest possible range of the spectrum from the average PC to soft X-ray (range 20 μm - 0.05 μm);

4. providing the possibility of expanding the tuning range of lasers tuned according to the wavelength (especially) at the edges of the tuning range by providing the possibility of operational regulation of the energy / power of the output radiation at the selected generation wavelength and current pump level without stopping (turning it off);

5. providing the possibility of simplified operation of the laser by eliminating the time-consuming process of alignment (adjustment) of the cavity mirrors after each replacement with the possibility of smooth regulation (increase and decrease, respectively) of the output power depending on the user's needs;

6. ensuring the stability of the spatial position of the output laser beam;

7. maintaining the operability of the claimed technical solution in various types of lasers - continuous, pulsed and ultrashort pulse-generating pulses;

8. the ability to derive the maximum laser energy / power for the current pump level for any type of laser without stopping (turning it off);

9. ensuring operability when used in lasers with resonators of any complexity: simple, two-mirror, with selector elements, annular, etc .;

10. ensuring economic efficiency during research and development;

11. ensuring economic efficiency in the operation of serial lasers.

The essence of the claimed technical solution lies in the method of output and regulation of the energy / power of the laser output radiation, which consists in installing a reflecting element on a moving base in the laser cavity at an angle to the resonator axis, the position of which determines the level of energy / power output after the laser is started, and setting the required level energy / pump power, characterized in that in the claimed method in the resonator of a pulsed or continuous laser between the output mirror of the laser, replaced by a non-transparent a conventional reflecting mirror, and an opaque reflecting mirror is mounted on the movable base as the reflective regulatory element, allowing this mirror to be moved parallel to its reflecting surface, from its complete withdrawal from the light field established in the resonator to the complete overlap of this field after entering this movable mirror, with the possibility of implementing not only the output of the laser energy / power, but also its regulation, namely smooth change nergii / power from zero to a maximum value and back to the pump at a predetermined level and positionable at a desired output energy level. A device that implements the method according to claim 1., Introduced into the laser cavity between the active medium and the output mirror of the laser, providing output and regulation of the energy of the output radiation of the laser, characterized in that it is made in the form of an opaque reflecting mirror mounted on a mechanical pair, a mechanism representing site for mounting the mirror and the base, interconnected by a screw-nut to provide reciprocating movement of this mirror parallel to its reflecting plane by installing this mirror on the mechanism at an angle to the axis of the resonator of a pulsed or cw laser.

In this case, a characteristic of the claimed technical solution is the originality (non-obviousness for the specialist) of the proposed solution due to the fact that it does not require a large set, usually consisting of 3-5 expensive individually made mirrors with different reflection coefficients, for the possibility of choosing from them mirrors with an optimal reflection coefficient for a given pump level to control the output laser energy / power with subsequent mirror alignment each time it is replaced by another for each of the spectral ranges: from medium infrared, infrared, visible, ultraviolet, vacuum ultraviolet and to soft x-rays, and the material and technical costs for optimizing the output energy / laser power are significantly minimized.

Schematically the claimed method is shown in Fig.9 and Fig.10. As an output mirror, a m2 mirror is installed in the laser resonator with the same characteristics as the mirror used in this laser as a “deaf” one, that is, like an M1 mirror, which has a reflection coefficient close to 100% at the laser generation wavelength ( or 0% transmission). Between the active element and the output mirror, a third flat opaque mirror m3 (hereinafter referred to as the output mirror) is introduced, the reflection plane of which is set at an angle to the axis of the resonator formed by the first two mirrors. The reflecting side of the output mirror must always face the active medium of the AC laser.

The radiation is output from the laser resonator by moving the output mirror along its reflection plane until it intersects with the region in which the standing wave of laser generation was generated, as shown in Fig. 10, where an enlarged fragment of the laser output part shown in Fig. 9 is shown.

Part of the radiation of a standing wave that hits the reflecting surface of the output mirror exits the cavity at an angle in accordance with the law of reflection. Further smooth movement of the output mirror in the direction of the cavity axis along the reflection plane will lead first to an increase in the output laser energy / power, and then, from some moment, to a smooth decrease until the generation fails. Thus, when moving this third mirror in the forward or reverse directions, one can find its position at which the output of the laser energy / power will be maximum for the current pump level.

The m2 and m3 mirrors form, as it were, the output mirror of the laser with a continuously variable transmission. Its transmittance is determined by the ratio of the area of the part of the spot of the standing wave of the laser on the m2 m2, covered by the mirror m3, to the remaining area of the spot of the standing wave on the m2 m2. By moving the m3 mirror, the transmission of the output laser mirror is smoothly adjusted to achieve the maximum possible level of output optical energy / power.

The use of this method of radiation output does not exclude the use of various devices on the other side of the resonator, i.e. from the side of the traditional installation of a blind mirror of a laser resonator. Here, as usual, you can use any elements - from just a blank mirror to mirrors with selective dispersion elements, which are traditionally used in tunable lasers, as well as various gate elements, often used to modulate the quality factor of laser resonators.

The claimed method of outputting radiation from the resonator can significantly expand the tuning range of tunable lasers. Moreover, the use of a device that implements the claimed method, allows you to quickly adjust the output radiation at a selected wavelength and the current level of pumping. This is especially true at the edges of the tuning range, when the gain of the active medium is lower, and in this case a more closed resonator is required, i.e. requires an output mirror with less transmission than in the middle of the range.

This method of outputting radiation from a blank cavity remains operational in various types of lasers that generate in a wide range of wavelengths from the mid-IR spectral region to vacuum ultraviolet (VUV) and even soft x-rays. Currently, the technology of applying dielectric coatings on substrates is well developed in the middle (visible and close to it) part of the indicated spectrum range. Thanks to this technology, until now, translucent mirrors have been manufactured for lasers emitting in this spectral region as output mirrors in laser cavities. At the edges of the range (middle IR and VUV as well as soft X-ray), the manufacture of translucent output mirrors is associated with a number of difficulties, in particular, the lack of materials for both the mirror base and coatings transparent in this area. That is why in lasers generating in these areas, special laser cavities are used that are designed for a specific task, for example, with holes of various diameters in metal optics (which is chosen as a prototype of this application). The claimed method allows you to solve this problem easily - two identical deaf mirrors, one of which is movable. The method is applicable to all types of lasers, both pulsed and continuous, and is also applicable to lasers emitting in all the spectral ranges of the spectrum mentioned here, including visible.

Experimental data

Embedding the output radiation control device into the laser cavity and its operation features

To prevent displacement of the beam of the output laser radiation during translational motion of the VZ mirror, it is necessary that the movement is carried out along its reflective plane (Figure 10).

Moreover, the angular orientation of this mirror relative to the axis of the resonator can be, within reasonable limits, any, however, each of these positions of the mirror B3 has its advantages and disadvantages. For example, when installing an OT mirror to the cavity axis at an angle of 45 °, when the radiation emitted from the cavity makes a right angle with the cavity axis, a relatively small mirror can be used for OT. To move such mirrors, precision nodes with a small limiting displacement are necessary (for example, operating on the basis of the piezoelectric effect). Moreover, if dielectric mirrors are used, then in this case mirrors with 100% reflection are best suited for an angle of incidence on them equal to 45 °. Mirrors with this characteristic, along with mirrors with other characteristics, are often offered by manufacturers.

In the case of the angle of incidence of radiation on mirror B3 close to 90 °, when the radiation practically slides along the surface of the mirror, a number of more significant advantages can be found. In this case, a longitudinal displacement unit with a significantly larger ultimate stroke is required. The spot of the laser beam on the moving mirror occupies a large area at the same energy as in the previous case, which means that the energy density on the mirror is significantly reduced, and therefore, mirrors with much lower radiation strength can be used. Defects of poor-quality processing of the mirror edge will make a smaller contribution to the diffraction loss of the resonator with this method of radiation output. Also in this case, instead of dielectric or metal mirrors, VZ can be used as a mirror, simple glass or quartz mirrors, etc. records. The transmission loss of the plates located at such an angle to the radiation is insignificant, however, these plates should be quite long.

Description of the experimental setup

The method of outputting radiation with an intracavity mirror described in this paper can be used in any laser that has some space between the active medium and the output mirror of the resonator. In this work, the study of the characteristics and properties of the output laser radiation using this method was carried out on a dye laser with quasi-longitudinal pumping, a diagram of which is shown in FIG. 10.

The active medium of this laser (Fig. 8) was the phenalemin 160 dye, dissolved in ethanol, which was pumped through a cuvette (3) with windows slanted relative to each other to prevent spurious generation on them. The active medium of the laser was pumped by the second harmonic of a YAG: Nd ³⁺ laser (1), which was focused into the medium by a lens (2). The resonator was composed of blind dielectric mirrors (6) and (10) and a blind mirror (5), brought with its edge to the axis of the resonator at an angle, with its dielectric coating facing the active medium. By moving the mirror (5) along its reflection plane when it intersects the resonator mode field, a controlled output of the laser generation energy was achieved. The prisms (7, 8) introduced into the laser cavity were dispersing elements, which made it possible to rearrange the laser radiation according to wavelengths. The dye laser was tuned by rotating the deaf mirror (10) around the axis normal to the plane of the figure. To ensure the generation of only one transverse mode, a diaphragm was introduced into the laser cavity (4). The wavelength was controlled by a spectrometer (13) by means of a fiber (12) by the fraction of the generated radiation passing through a deaf dielectric mirror (10), which was scattered by a frosted glass plate (11) to reduce the intensity of this radiation. The output laser radiation power was recorded using a meter (9) connected to the same computer. The data stream was processed by a computer (14).

Experiment Results

The results obtained with the intracavity device with mirror 5 (see Fig. 8) are shown in Figure 3, which shows that for each wavelength there is an optimal mirror position at which the value of the output power is maximum. Indeed, it corresponds to the optimal value of the intracavity losses corresponding to the gain of the active medium at the selected wavelength at a given pump level.

This figure also shows that there is a range of positions of the OT mirror at which it is possible to smoothly adjust the power output from the resonator from zero to maximum (i.e., solving goal 2).

In addition, the graphs (Fig. 11) show the maxima of the dependence of the output power of the dye laser with the intracavity device "output radiation" from the position of its mirror relative to the edge of the intracavity radiation beam. These curves were obtained as a result of measurements at each of the laser wavelengths: 585, 590, 600, 615, 630, 645, 660 nm, to which the laser wavelength was tuned before each series of measurements. The measurements for these curves were carried out without turning off the laser (i.e., solving goal 2). And accordingly, the level of output energy at the maximum can be found and installed without turning it off by simply moving the mirror (i.e., solving goal 1).

In total, the above described proves the solution to Problem 8 and Problem 2. In addition, from the description of the experiment, it is obvious that the operation of the laser is simplified, since there was no time-consuming process of alignment (adjustment), since there was no replacement of the cavity mirrors in the experiments (i.e., it corresponds to solving the problem 5).

To compare the results obtained in Fig. 11 with the data obtained by the traditional method of optimizing the output radiation, the laser output power was measured at the same wavelengths using a number of mirrors with different transmittance, which were alternately installed in place of the mirror (6) , - (6 ') as the output, see Fig. 8. In this case, the device with the mirror (5) was removed from the resonator. Accordingly, the energy meter (9) was rearranged in place (9 '). The obtained dependency graphs are presented in Fig. 12.

When comparing the dependencies shown in Fig.11 and Fig.12, we can note their identical nature of the changes. That is, the dependencies on both graphs have maximums and their intersections with zero.

For their explicit comparison, the authors constructed the dependences of the maximums on the wavelength obtained in both experiments. These dependencies are shown in Fig.13. The values of the intensities of the maxima taken from measurements with an output device over the edge, in comparison with measurements with interchangeable mirrors with different transmittance at each measured spectral point, differ on average by a constant value of ~ 0.2. This value can be defined as the value of losses when using the OT device.

These losses include several components, the main of which is the loss on the mirror, which was used in the control device. The dielectric coating of the mirror taken for these experiments was calculated for 100% reflection under normal incidence of radiation on it. It is known that at other angles, such mirrors become partially transmissive. Thus, the main losses include losses due to incomplete reflection of the dielectric coating of the used mirror — partial transmission of the radiation reflected from it. However, manufacturers currently offer dielectric mirrors with 100% reflection at a dip angle of 45 °. A metal mirror can also be used as such a mirror. Scratches on the surface of an arbitrarily taken mirror are not excluded from loss calculations.

In conventional lasers, a translucent mirror, which has a fixed reflection coefficient, is traditionally used to output radiation. The designers of each laser usually select this mirror from the conditions initially set for its operation and remain constant. And such a laser has a maximum efficiency only at a certain pump level, for all other pump levels, the efficiency will be lower than at this certain level.

While due to the fact that when using mirror 5 (Fig. 8), it is possible to smoothly change the output radiation with bringing it to the maximum at any level of the selected pump, it is possible to quickly bring the level of output radiation to a maximum, that is, achieving maximum efficiency at each pump level (i.e., the solution to problem 1).

To give an idea of the intensity distribution in the spot of the laser radiation emitted by the intracavity VZ device, Fig. 14 shows a photograph of this spot on the screen that did not experience any displacements on it, only its intensity changed (i.e., the solution to Problem 6). On Fig shows a graph of the distribution of intensity in the output beam in cross section.

It can be seen from the obtained data that, using the described method for extracting radiation from the resonator, the beam at the laser output remains Gaussian.

Application of the device in a tunable laser

The use of the device in the cavity of a tunable laser allows us to expand its spectral range of tuning. This becomes possible due to the fact that this method makes the cavity more closed for cases when the gain of the active medium is small, which occurs at the edges of the tuning curve for most tunable lasers.

On Fig presents two tuning laser curves obtained on the dye phenalemin 160. These curves were obtained on a tunable laser, a diagram of which was shown in Fig. 8.

The main part of the tunable laser optical schemes in both experiments was classical: a 60-degree prism was used as a dispersing element, and a dielectric mirror with a flat spectral characteristic corresponding to the spectral region of the dye luminescence was chosen as a highly reflecting “deaf” mirror. But the methods for outputting radiation from the resonator were different. In one of them, a traditional output mirror was used, which was optimal for a tunable laser at the maximum of the tuning curve. For the second implementation of the dye laser circuit, this optimal output mirror was replaced with a “dull” one with a reflection of 100%. To output the radiation from the laser cavity, we used a plane mirror with 100% reflection, which was mounted on a moving base and introduced into the cavity at an angle to its axis.

In experiments with a tunable laser, the energy at the laser output was measured at various points in the tuning curve for both laser designs. In the case when in the experiment a device with a moving mirror 5 was used to output laser radiation (see Fig. 8), after tuning to a new wavelength of the tunable laser, the output radiation using the device with a moving mirror 5 was adjusted to the position of the maximum possible output laser power. The pump energy of the tunable laser was unchanged in all experiments. On Fig shows that the adjustment curve in the case of applying the method of energy output using a moving mirror is a total wider by 7 nm compared to the curve obtained using the conventional method of outputting laser radiation. This became possible due to the fact that when using the new method of outputting radiation, it became possible to make the laser resonator more “closed” along the edges of the tuning curve of the laser during its operation. Thus, the result described above corresponds to the solution of Problem 4 and Problem 9 - a two-prism selection element was used in the experimental laser.

Thus, in contrast to the classical laser resonator using the described method, it is possible to correct the output power level output from the laser resonator at any time without turning off the laser itself. In addition, using the described method, it is possible to obtain any predefined shape of the tuning curve, for example, a flat curve with a constant level of laser output power when the radiation wavelength changes, which is important for laser spectroscopy (not stated in the list of 11 problems to be solved, but which may decide).

From the above report, the tasks of the claimed technical solution 3, 7, 10 and 11 remain unproven

In relation to these tasks, applicants report the following:

1. By solving Problem 3: When using metal optics, as in the case of a.s. SU 884526 A1, this task is easily performed.

2. By solving the problem 7. In contrast to the opposed A.S. SU 884526 A1 and patent RU 2239921 C1, which specifically specify the time parameters of the output radiation, in the claimed technical solution specifically stipulated: "energy / power regulation", technically this means: regulation of pulsed and continuous radiation. In addition, from the principle of operation of the claimed device in the claimed technical solution, it is obvious that it does not in any way affect the temporal characteristics of the laser, and the intracavity light field, part of which is output by the device, is installed in all types of lasers - pulsed, continuous, ultra-short duration and etc.

3. By solving problems 10 and 11, their implementation is obvious from the description of the above experiments, as well as a detailed description of the arguments given in the applicant's response to the expert opinion.

ADVANTAGES OF THE INVENTED METHOD is as follows:

AGAINST THE METHOD described in tax 1 (Figure 1):

1. In the inventive method, the regulation of the output power / energy of the laser can be carried out quickly and smoothly, from the mode of its operation in the dead cavity to the mode in the fully open resonator, passing through the mode with the maximum output power / energy without turning off the laser. Moreover, all the power output from the resonator is used as useful.

In method 1, the level of output power is initially determined by the transmission of the output mirror of the laser (16) and the power can ONLY be REDUCED from the level specified by the mirror 16, which has a fixed transmittance. Moreover, the removed part of the radiation is lost in the absorber;

2. The claimed method is applicable to lasers operating in a wide spectral range, from the middle infrared range of the spectrum, to the vacuum-ultraviolet, including the visible and ultraviolet ranges.

The application of method 1 is limited by the spectral transmission range of the used transparent plate;

3. In the claimed method, the spot of the output radiation does not experience any displacement when regulating its power / energy.

In method 1, the output radiation spot is displaced due to the refraction of the beam in the plate of finite thickness, which is used for regulation. Moreover, this shift depends on the thickness of the plate and the greater the greater its angle with respect to the axis of the resonator.

Design advantages of the node that implements the claimed method:

In the inventive method, only one element is added to the resonator - a third mirror with a moving device.

Method 1 requires three additional elements: a transparent plate 21, a mirror 22 and an element that absorbs radiation, and devices for each of them.

AGAINST THE METHOD described in analogue 2 (Figure 2):

1. The claimed method is applicable to lasers operating in a wide spectral range, from the middle infrared range of the spectrum, to the vacuum-ultraviolet, including the visible and ultraviolet ranges.

The application of method 2 is limited by the spectral transmission range of the used transparent plate;

2. When applying the inventive method, stability of the spatial position of the output laser beam is ensured when controlling the output laser energy / power over the entire output range.

In method 2, when controlling the energy / radiation power, the direction of the output radiation changes quite significantly: the angle between the extreme positions of the output beam is tens of degrees. In this case, it is necessary to move the “consumer” of the radiation of such a laser, for example, a target, and again direct the radiation to the same spot where the radiation fell before adjusting the output power.

3. the claimed method does not introduce additional losses when regulating the energy / radiation power in the laser - all the output radiation is used as useful.

In method 2, reflection will always be present in the direction opposite to that indicated in the diagram of FIG. 2 (not shown by the authors in the figure), this is a channel of additional losses, which reduces the efficiency of the entire laser.

Design advantages of the node that implements the claimed method:

In the claimed method, only one element is added to the resonator - the third mirror. Moreover, to control the power / energy of the laser in this way, you will need a node only for its longitudinal movement, otherwise the laser with this node can be used in the same way as without it.

In method 2, for a plate with which regulation is carried out, a node will be required for its rotation, which is structurally more difficult to implement. In addition, a laser with this control method will require a special rotary table for its irradiated objects.

AGAINST THE METHOD described in analogue 3 (Figure 3):

1. The application of the claimed method is possible in the entire optical range: from medium IR to soft x-ray, including visible UV and VUV ranges.

The application of method 3 is limited by the transparency range of the base and the sprayed materials in general and, even more, the spectral range is narrowed by the concrete implementation of the wedge filter - in particular.

2. In the inventive method, the mirror that removes the radiation does not participate in the process of generating laser radiation - it only selects part of it for output from the resonator. This means that when moving the output mirror, the laser cavity is not upset.

In method 3, the filter wedge is the output mirror of the laser and when it moves, the slightest deviation of the mirror plane from the normal to the axis of the resonator will lead to misalignment of the laser and, consequently, to the generation failure.

3. In the claimed method, even a simple polished plate mounted at a sliding angle can be used as an output mirror.

In method 3 there are no other options, and its implementation is due to the complex technology and the high cost of applying dielectric coatings of variable thickness.

Design advantages of the node that implements the claimed method:

The implementation of the design of the node for method 3, when it performs the role of the output mirror, is very problematic. That is, in addition to conventional adjustment screws, this assembly must have a device for extended movement, moreover, it is very precise, but even with that, maintaining the adjustment is problematic. That is why in the described method 3 in the patent, automatic adjustment of the electronically controlled wedge filter is used.

In the claimed method, a simple displacement unit can be used, since it does not affect the alignment of the resonator.

AGAINST THE METHOD described in analogue 4 (Figure 4):

1. In method 4, a large number of reflective planes is associated with a large number of optical elements that introduce additional losses into the resonator, which negatively affects the output characteristics of the laser.

In the claimed method, “extra” reflection planes are absent.

2. In method 4, the use of birefringent optical elements and elements for rotating the plane of polarization limits the application of this method to a narrow spectral range.

In the claimed method, such restrictions are absent.

3. In method 4, the range of regulation of the output fraction of radiation and the need to use polarized active elements are limited.

In the claimed method, such restrictions are absent.

Design advantages of the node that implements the claimed method:

In method 4, in comparison with the claimed method, an additional element with an alignment unit is required, moreover with precision rotation of the element.

AGAINST THE METHOD described in analogue 5 (Figure 5):

When applying method 5, the low spatial coherence of the laser beam — it consists of two halves, and therefore, in the block of mirrors, the angle between the mirrors must be kept equal to 90 degrees as accurately as possible, otherwise these halves of the beam will diverge at a large distance.

In the claimed method, this disadvantage is absent, one beam is extracted from the laser cavity.

Design advantages of the node that implements the claimed method:

In method 4, a structurally complex radiation output device requires 2 mirrors for output and 3 precision units with additional adjustments.

In the inventive method for outputting radiation from the resonator requires only one mirror with a device for moving it.

AGAINST THE METHOD described in analogue 6 (Fig.6):

1. The transmission of a device that implements the claimed method of outputting the laser radiation power / energy is determined, as in method 6, by the ratio of the area of the spot of the output radiation to the area of the remaining part of the standing wave on the mirror of the laser resonator. However, if in the case of method 6 this ratio is fixed, then in a device that implements the claimed method of outputting radiation power / energy, the transmission can smoothly change from 0 to 100% without disturbing the alignment of the resonator itself. In the case of applying the method of controlling the output of radiation / power according to one of the analogue 6 circuits shown in Fig.6 (Fig. 1.2b and 1.2c in Ishchenko’s book), if necessary, regulation to optimize the output power of such a laser requires a set of output mirrors. That is, mirrors with different hole diameters in the case of 1.2b or different mirror diameters in the case of 1.2.c, which are replaced (selected) in turn, and each time a mirror is replaced, a new resonator alignment is required. It leaves the mirror that gave the best result for the maximum output of radiation (moreover, for the pump level set at the current moment).

2. In addition, if regulation is necessary to optimize the output of radiation from a laser having a frequency tuning using method 6, a mirror optimized for one radiation frequency at the maximum output power will not be optimal for another radiation frequency. This is due to the non-uniformity of the gain spectrum of the active medium of any tunable laser. To achieve the maximum tuning range of a frequency-tunable laser, a separate optimization of the output mirror is required with the replacement of mirrors with different transmittance values (hole diameters) in the general case for each frequency, and especially for the frequencies at the edges of the range.

When applying the inventive method, the optimization of the output of the tunable laser radiation is carried out by simply turning the mirror adjustment knob 3 during laser operation.

3. The claimed method does not interfere with the laser generation process in the process of regulation - the cavity mirrors are not mechanically connected with the adjustable mirror, that is, the laser cavity is not upset.

Advantages in the constructive implementation of the claimed method:

To implement the regulation of the output of radiation / power according to one of the analogue 6 schemes, a set of 3-5 mirrors with different transmittance and alignment of the entire laser when replacing one mirror with another will be required. To these inconveniences in the case of a laser operating in the vacuum-ultraviolet region of the spectrum, when replacing one mirror with another, the need for depressurization and subsequent sealing of the box in which this laser is placed is added.

When applying the inventive method for controlling the output radiation / power of a laser emitting in the vacuum-ultraviolet region of the spectrum, the advantages of the inventive method of regulation become even more obvious, since in this case the regulation can be carried out using the handle on the roller connected to the node of the output mirror, the second end which is removed from the evacuated box through the seal. In this case, depressurization of the box during regulation is not required.

In comparison with the prototype in the claimed technical solution, the regulation is not the duration of the pulses, namely the output energy / laser power.

The claimed technical solution meets the criterion of "novelty" presented to the invention, because from the prior art examined by the applicant on the filing date of the application, there are no signs matching the signs of the claimed technical solution.

The claimed technical solution meets the criterion of "inventive step" for inventions, because for a specialist, it does not explicitly follow from the prior art.

The applicants made a prototype operating in the visible wavelength range, the tests of which confirmed the achievement of the set goals and the presence of these advantages compared to known devices, including significant advantages over the prototype, the claimed technical solution can be implemented in lasers with different operating principles produced and already in economic circulation, and does not require the use of special industrial equipment, which allows us to conclude that and the criterion of "industrial applicability" for the invention.

Claims (2)

1. The method of output and regulation of the energy / power of the output laser radiation, which consists in installing in the laser cavity at an angle to the axis of the resonator a reflective element on a moving base, the position of which determines the level of output energy / power after starting the laser and setting the required level of energy / pump power, characterized in that in the claimed method, into the cavity of a pulsed or continuous laser between the output mirror of the laser, replaced by an opaque reflective mirror, and the end of its active element an opaque reflecting mirror is installed as a reflecting regulatory element on a movable base, which allows this mirror to be moved parallel to its reflecting surface, ranging from its complete withdrawal from the light field established in the resonator to the complete overlap of this field after entering this movable mirror, with the possibility of not only the output of the energy / power of the laser, but also its regulation, namely the smooth change of energy / power from zero to maximum value and of inverse for a given pump level and the possibility of installing energy output at the required level. 2. A device that implements the method according to claim 1, introduced into the laser cavity between the active medium and the output mirror of the laser, providing output and regulation of the energy of the output laser radiation, characterized in that the device is made in the form of an opaque reflecting mirror mounted on a mechanical pair mechanism, representing a node for mounting the mirror and the base, interconnected by means of a screw-nut to provide reciprocating movement of this mirror parallel to its reflective plane, p Then we install this mirror on the mechanism at an angle to the cavity axis of a pulsed or cw laser.

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