Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J65/00—Lamps without any electrode inside the vessel; Lamps with at least one main electrode outside the vessel
  • H01J65/04—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/025—Associated optical elements
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/36—Seals between parts of vessels; Seals for leading-in conductors; Leading-in conductors
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/54—Igniting arrangements, e.g. promoting ionisation for starting

Definitions

• the present invention relates to high-brightness broadband light sources with continuous optical discharge.
• a stationary gas discharge sustained by laser radiation in pre-created relatively dense plasma is known as continuous optical discharge (COD).
• COD continuous optical discharge
• a COD, sustained by a focused beam of a continuous wave (CW) laser is realized in various gases, in particular, in Xe at a high gas pressure of up to 200 atm (Carlhoff et al., “Continuous Optical Discharges at Very High Pressure,” Physica 103C, 1981, pp. 439-447).
• COD-based light sources with a plasma temperature of about 20,000 K (Raizer, “Optical Discharges,” Sov. Phys. Usp. 23(11), Nov. 1980, pp. 789-806) are among the highest brightness continuous light sources in a wide spectral range between about 0.1 pm and 1 pm.
• pulsed lasers with a high pulse rate may be used as well, also in combination with CW laser with a power of not lower than the threshold value required to stably sustain the COD, for example, as described in RU Patent 2571433 published on 20.12.2015.
• COD-based light sources Compared to arc lamps, COD-based light sources not only have a higher brightness, but also a longer lifetime, making them preferable for a variety of applications.
• COD plasma has an elongated shape along the laser beam axis, and plasma radiation is collected in the longitudinal direction, that provides for high brightness of the source.
• the shape and design of the chamber as well as COD sustaining conditions may not be optimal to achieve the highest possible brightness of the light source, in particular, due to optical aberrations introduced into the path of radiating plasma rays by the transparent walls of the chamber.
• the light source has no provisions to eliminate optical aberrations introduced into the useful beam of plasma radiation when it passes through the transparent walls of the chamber, reducing brightness of the light source.
• disadvantages caused by electrodes used for starting plasma ignition are inherent in the light source.
• Another disadvantage of this design is the propagation through the transparent chamber walls of both plasma radiation and unabsorbed laser radiation passing through the plasma, which requires special measures to block it.
• the technical problem and technical result of the invention refers to the creation of broadband light sources with the highest possible brightness and stability, also characterized by compensation of aberrations, both when laser radiation is incoming into the chamber and when broadband plasma radiation is outcoming from it.
• a laser-pumped plasma light source containing: a chamber filled with high-pressure gas, a region of radiating plasma sustained in the chamber by a focused beam of a continuous wave (CW) laser; at least one beam of plasma radiation exiting the chamber, and a means for plasma ignition.
• CW continuous wave
• the laser-pumped light source is characterized in that the chamber comprises or consists of a tube, a bottom and a cap; one end of the tube is hermetically connected to the bottom, while the other end of the tube is hermetically connected to the cap; the tube and the bottom are made from an optically transparent material; the bottom is arranged for introducing the focused beam of the CW laser; the tube may be configured to allow the beam of plasma radiation to exit from the chamber over at least 70%, 80%, 90% or even 100% of the full azimuthal angular range.
• the azimuthal angle may refer to a plane (azimuth plane) that is perpendicular to the axis of the beam of the CW laser (e.g.
• the tube excluding its end parts may be arranged for exit of the beam of plasma radiation from the chamber in all azimuths (e.g. with respect to the azimuth plane).
• the cap may be made from a metal and/or may be equipped with a gas inlet.
• the means for plasma ignition is a pulsed laser system generating at least one pulsed laser beam focused in the chamber.
• the bottom of the chamber may be arranged for introducing the one or more, preferably each, pulsed laser beam into the chamber.
• a portion of the tube arranged for exit of the beam of plasma radiation has an axis of symmetry, a center of symmetry, a cylindrical shape of an internal surface, a barrel-like or a toroidal shape of an external surface, and said center of symmetry is located at the region of radiating plasma.
• the beam of the CW laser is focused in the chamber by means of an optical system comprising the chamber bottom and a focusing optical element with a surface minimizing total aberrations of the optical system.
• the focusing optical element is an aspherical lens.
• the focusing optical element e.g. a lens
• the focusing optical element is fixed in a rim, which in turn is fixed on an end part of the tube at the end at which the bottom is provided.
• bottom of the chamber is in the form of a lens.
• a part or a detail of the cap is designed as a concave spherical mirror with a center in the region of the radiating plasma.
• the concave spherical mirror radius is not more than 5 mm.
• the focused beam of the CW laser is directed into the chamber vertically upwards.
• a part of the cap is made of a refractory material such as tungsten, molybdenum or alloys based thereof.
• a radius of the internal surface of the tube is not more than 5 mm, preferably not more than 3 mm.
• the radius may in particular be a radius perpendicular to the symmetry axis of the tube, e.g. perpendicular to the tube’s longitudinal axis.
• the tube and/or the bottom of the chamber are made from a material belonging to a group of sapphire, leuco sapphire, fused quartz, crystalline quartz.
• the end parts of the tube are used.
• the tube and the bottom of the chamber may be sealed with glass cement.
• the cap and tube of the chamber may be sealed using soldering.
• the cap is equipped with a gas inlet arranged for filling the chamber with the gas or/and controlling a pressure and a composition of the gas in the chamber.
• the cap of the chamber is equipped with a heater.
• the means for plasma ignition is a solid- state laser system generating a pulsed laser beam in Q-switching mode and a pulsed laser beam in free-running mode.
• the chamber is located in an external bulb that is external to the chamber, in particular surrounds or encloses the chamber.
• the laser-pumped plasma light source further comprises an optical collector.
• the optical collector is multichannel, comprising at least three channels.
• the invention in another aspect, relates to a method for reducing aberrations in a laser- pumped plasma light source, characterized by sustaining a radiating plasma in a gas-filled chamber by a focused beam of a continuous wave (CW) laser and exiting a beam of plasma radiation from the chamber.
• CW continuous wave
• the method may include the use of the chamber comprising or consisting of a tube, a bottom and a cap, while the cap is equipped with a gas inlet, the bottom is arranged for introducing the focused beam of the CW laser into the chamber, the tube is arranged for exit of the beam of plasma radiation.
• the tube may be arranged to allow the beam of plasma radiation to exit from the chamber over at least 70%, 80%, 90% or even 100% of azimuthal angles in a plane (azimuth plane) that is perpendicular to the axis of the beam of the CW laser (e.g. corresponding to the tube’s longitudinal axis or axial direction, e.g. the symmetry axis) and passes through said region of radiating plasma.
• the tube may in particular be arranged for exit of the beam of plasma radiation in all azimuths.
• the method may further include reducing aberrations which distort a path of rays of beam of plasma radiation passing through a tube wall, by making use of a tube that has an axis of symmetry, and a center of symmetry, which may be located at the region of radiating plasma.
• the tube may have a cylindrical shape of an internal surface and/or a barrel or a toroidal shape of an external surface.
• the axis of symmetry may correspond to a cylinder axis of the cylindrical shape.
• the beam of the CW laser is focused by means of an optical system including the bottom and an aspherical lens with a surface minimizing total aberrations of the optical system.
• the beam of plasma radiation exits the chamber in a solid angle of not less than 9 sr.
• Ignition of continuous optical discharge (COD) without the use of igniting electrodes allows to significantly increase the solid angle of the output beam and the power in the useful beam of plasma radiation.
• the cap serves to suppress turbulence of convective gas flows in the chamber, and also blocks the laser radiation transmitted through the plasma, that provides both high output stability of light source and highly effective elimination of laser radiation in a beam of plasma broadband radiation.
• Using a metal cap equipped with a gas inlet provides the possibility to optimize the gas pressure and temperature in the chamber to obtain maximum brightness and stability of the light source.
• placing the gas inlet on the cap provides optimization of the light source design, since it provides unimpeded output of the beam of plasma radiation from the chamber in all azimuths.
• Making a part of the cap of the chamber in the form of a concave spherical mirror with its center in the region of radiating plasma allows an additional increase the brightness of the light source.
• the proposed light source provides for sharp focusing of the laser beam in the radiating plasma region.
• the proposed shape of the chamber reduces aberrations introduced into the beam of plasma radiation when it exits the chamber. All of these, together with optimization of gas temperature and pressure, increase brightness of the light source.
• chamber material which allows for expanding the variety of applied gas compositions, in particular, metal-halide additives when used with sapphire, is also realized.
• the invention provides for a possibility to increase brightness, power capacity, and quality of radiation of the laser-pumped light source, substantially improves its spatial and power stability, and expands options to control the plasma radiation spectrum.
• FIG. 1 Schematic diagram of laser-pumped plasma light source in accordance with an embodiment
• FIG. 2A and Fig. 2B Illustration of reduction of the light source brightness due to aberrations caused by the tube wall (Fig. 2A) and of the mechanism of their suppression (Fig. 2B),
• FIG. 3A and Fig. 3B Schematic diagram of the focusing optical system (Fig. 3 A) and calculated laser power distribution in the focal spot (Fig. 3B),
• Fig. 4 Schematic diagram of the light source in accordance with embodiments
• Fig. 6 Schematic view of the light source with three-channel optical collector.
• FIG. 7 Schematic diagram of the light source chamber, equipped with an external bulb.
• the laser-pumped light source comprises chamber 1 filled with high-pressure gas, typically higher than 10 atm.
• Chamber 1 contains radiating plasma region 2 sustained by focused beam 3 of CW laser 4.
• the optical collector comprises, according to an embodiment of the invention, a parabolic mirror 6 that forms a beam of plasma radiation 7, which is transmitted, for example, via an optical fiber or a system of mirrors to optical consumer system 8, which uses broadband plasma radiation.
• the light source is characterized in that the means for plasma ignition is a pulsed laser system 9 generating as least one pulsed laser beam 10 focused in chamber 1, namely into the region intended for sustaining radiating plasma 2.
• chamber 1 comprises or consists of a tube 11, a bottom 12 and a cap 13. One end of tube 11 is tightly connected to bottom 12, and the other end of tube 11 is tightly connected to cap 13. Cap 13 is intended for filling the chamber with gas, for example, through a tube 14 sealed off after the filling. Tube 11 and bottom 12 of the chamber are made from optically transparent material.
• the bottom is intended for introducing focused beam 3 of CW laser 4 into the chamber, as well as one or more, preferably each one of pulsed laser beams 10 used for plasma ignition.
• Tube 11 of the chamber is intended to output beam 5 of plasma radiation from chamber 1.
• the shape of tube 11 incorporates the function of reducing aberrations, which distort the path of rays of plasma radiation when they pass through the tube walls.
• Complete elimination of aberrations is achieved when the parts of external and internal surfaces of the chamber, through which beam 5 of plasma radiation exits the chamber, are the parts of two concentric spheres, that may be difficult to implement.
• a part of the internal surface of tube 11 is cylinder-shaped, as shown in Fig. 1.
• a significant reduction in aberrations is achieved in preferred embodiments of the invention, in which a portion of the tube 11 arranged for exit of the beam of plasma radiation 5 has an axis of symmetry, a center of symmetry, a cylindrical shape of an internal surface, a barrel-like or a toroidal shape of an external surface and said center of symmetry is located at the region of radiating plasma 2, Fig. 1.
• aberrations are reduced by using a relatively simple and easy-to-fabricate chamber 1.
• Fig. 2a shows a schematic diagram of a homocentric beam from quasi-zero- dimensional radiating plasma region 2, passing through the walls of circle-and-cylinder-shaped tube 11.
• the beam opening angle immediately near radiating plasma region 2 is designated with optical rays 15.
• the rays are refracted in accordance with Snell’s refraction law:
• ni sinOi n 2 sinO 2 (1)
• ni refraction index of the medium, from which the light falls on the interface
• n 2 refraction index of the medium, to which the light spreads after having passed the interface
• 0i light incidence angle, i.e. the angle between a ray incident on the surface and a normal to the surface
• 0 2 light refraction angle, i. e. the angle between a ray passed through the surface and a normal to the surface
• rays 15’ after passing through the tube walls, are not only displaced from rays 15, but also inclined to the propagation direction of rays 15 near radiating plasma region 2.
• a beam with opening angle designated with rays 15’ remains almost homocentric, and radiating plasma region 2’ visible from the side of rays 15’, which have passed the tube of the chamber, remains quasi-zero-dimensional.
• the light source remains quasi-zero-dimensional for optical consumer systems using the beam passed through accordingly shaped tube 11 of the chamber, Fig. 2b.
• This provides evidence of efficient elimination of the aberrations, which may significantly reduce brightness of the light source in the tube configurations shown as an example in Fig. 2a.
• the external surface of the tube is shaped in such a way that eliminates chromatic and spherical aberrations.
• R F * r * (1 + r/d), wherein the factor F lies within the range of 2 to 4.
• the laser-pumped plasma light source operates as follow. Focused beam 3 of CW laser 4 is directed into chamber 1 comprising tube 11, the ends of which are tightly connected to bottom 12 and cap 13 of the chamber, Fig. 1. Cap 13 is intended for filling the chamber with high-pressure gas, for example more than 10 atm. Xenon. Other inert gases and their mixtures may be used for filling, including those containing metal vapors, for example, mercury, or various gas mixtures, including those containing halogens.
• Pulsed laser system 9 generates at least one pulsed laser beam 10 focused in region 2 of the chamber which region is intended for sustaining radiating plasma 2.
• the beams of CW laser 4 and pulsed laser system 9 are introduced into chamber 1 through a focusing optical element 16 and bottom 12 of the chamber.
• Pulsed laser system 9 provides for the optical breakdown and generation of an initial plasma with a density higher than the threshold plasma density of the continuous optical discharge (COD) having a value in the order of 10 18 electrons/cm 3 .
• Concentration and volume of the initial plasma are sufficient to stationarily sustain the COD with a focused beam 3 of CW laser 4 of a relatively low power, not exceeding 300 W.
• high- brightness broadband radiation is output from radiating plasma region 2 of the COD by at least one output beam 5 of plasma radiation intended for subsequent use. Beam 5 of plasma radiation exits the chamber through tube 11, the external surface of which is shaped to reduce aberrations that distort the path of rays of plasma radiation when they pass through the tube wall.
• Fig. 1 shows that according to present invention tube 11 of the chamber, except for its near-end parts used to seal the chamber, is intended for exit of beam 5 of plasma radiation from the chamber in all azimuths.
• the beam of plasma radiation exits the chamber in all azimuths from 0° to 360°.
• the opening angle (in the plane of the drawing in Fig. 1) of beam 5 is not less than 90°.
• the beam 5 of useful plasma radiation exits from chamber 1 to optical collector 6 in a solid angle, which is not less than 9 sr or more than 70% of the full solid angle.
• beam 3 of CW laser 4 is focused in chamber 1 by means of an optical system comprising bottom 12 of the chamber and focusing optical element 16.
• a mirror for example, off-axis parabolic mirror or, preferably, a lens 16 due to its small size, as shown in Fig. 1, may be used as a focusing optical element.
• the bottom 12 is, preferably, made in the form of an optical element, quite a simple to make it commercially available, for example, in the form of a plate with spherical and/or flat surfaces.
• the optical element 16 located outside the chamber and having a more complicated shape than the bottom of the chamber incorporates the function of minimizing total aberrations of the optical system comprising optical element 16 itself and the bottom 12 of the chamber.
• Fig. 3a shows a schematic diagram of the optical system intended for focusing the laser beam, which comprises bottom 12 of the chamber in the form of a flat-convex spherical lens and focusing optical element 16 in the form of a flat-convex aspherical lens.
• the bottom of the chamber and the aspherical lens are made of different materials, which allows for optimizing characteristics of the optical system of these two elements more flexibly.
• FIG. 3b show that an optical system realized in accordance with the present embodiment, in general, allows for focusing about 90% of the laser beam power in a spatial region with a radius of as small as 2.5 pm at a distance d of « 4 mm from the bottom of the chamber.
• the present invention admits other embodiments, in which the sharp focusing of beam 3 of the CW laser is provided by only one focusing lens, in particular, aspherical, which is the bottom 12 the chamber.
• the axis of the focused beam 3 of CW laser 4 is directed close to vertical or vertically upward, that is, against the force of gravity 17, FIG. 4. If implemented according to the proposed embodiment, the highest radiation power stability of the laser-pumped light source is achieved. This is associated with the fact that radiating plasma region 2 is typically displaced from the focus towards focused beam 3 of the CW laser up to that cross-section of the focused laser beam where the intensity of focused beam 3 of the CW laser is still high enough to sustain radiating plasma region 2.
• radiating plasma region 2 containing the highest-temperature and low mass density plasma, tends to float under the action of the buoyant force.
• Radiating plasma region 2 when rising, ends up in the location closest to the focus where the cross-section of focused beam 3 of the CW laser is smaller, and the laser radiation intensity is higher. On the one hand, this increases brightness of the plasma radiation, and on the other hand, it equalizes the forces acting on the radiating plasma region, which ensures high stability of radiation power of the high-brightness laser-pumped plasma light source.
• chamber 1 is axially symmetric, and the axis of focused beam 3 of the CW laser is aligned with the axis of symmetry of the chamber.
• the turbulence of convective flows in the chamber is suppressed, in particular, by means of reducing its dimensions. This is easily realizable in the proposed design of the laser- pumped light source, the embodiments of which are characterized in that the radius of the internal cylinder-shaped surface of the tube is less than 5 mm, preferably, not exceeding 3 mm.
• Stability of output parameters of the laser-pumped light source is also influenced by a value of momentum acquired under the action of the buoyant force by the gas heated in radiating plasma region 2. The closer the region of plasma radiation 5 to the upper wall of the chamber, the smaller the momentum acquired by the gas and the turbulence of the convective flows.
• a part or part 18 of cap 13 of the chamber is located close to the radiating plasma region 2 at a distance less than 3 mm, minimum possible in order to avoid sensible negative effect on the light source lifetime.
• part 18 of the cap may be made of a refractory material such as tungsten, molybdenum or alloys based thereof.
• Part 18 of the cap may also be made with the function of reflecting and focusing in radiating plasma region 2 of laser radiation passed through the radiating plasma region, and broadband plasma radiation. This increases the plasma temperature, and brightness and efficiency of the light source.
• part 18 of the cap is made in the form of a concave spherical mirror 19 with a center (of the spherical mirror surface) in the radiating plasma region 2.
• tube 11 and bottom 12 of the chamber may be fabricated as an integral unit from a single piece of material, Fig. 4.
• tube 11 and bottom 12 of the chamber are tightly sealed using refractory glass fiber reinforced cement ensuring long lifetime of the light source at high temperatures, above 900 K.
• cap 13 and tube 11 of the chamber are tightly sealed by means of brazing with the use of a high-temperature braze, preferably, with a melting point not less than 900 K.
• the near-end part of the tube 11 of the chamber is metalized.
• the cap of the chamber may include or consist of several pieces or parts made of either metal or ceramics.
• tube 11 and bottom 12 of the chamber are made of a material from the group comprising sapphire, leuco-sapphire, fused and crystalline quartz, which have the most distinguished optical, physical, chemical and mechanical properties.
• a detailed example of the light source according to the present invention is shown as a schematic diagram in Fig. 5.
• a solid-state laser system comprising first laser 20 to generate first laser beam 21 in the Q-switching mode and second laser 22 to generate second laser beam 23 in the free-running mode.
• the pulsed lasers with active elements 24, 25 are equipped with optical pumping sources, for example, in the form of flash lamps 26 and, preferably, have common mirrors 27, 28 of the cavity.
• First laser 20 is equipped with a Q-switch 29.
• Two pulsed laser beams 21, 23 are focused in the chamber, in the region intended to sustain radiating plasma 2, Fig. 4.
• First laser beam 21 is intended for starting plasma ignition or optical breakdown.
• Second laser beam 23 in intended to create plasma, the volume and density of which are enough to stationarily sustain radiating plasma region 2 with focused beam 3 of the CW laser.
• a high-efficiency near-infrared diode laser with the output to an optical fiber 29 is used as a CW laser 4.
• the expanding laser beam is directed to collimator 30, for example, in the form of a collecting lens.
• expanded parallel beam 31 of the CW laser is directed to focusing optical element 16, for example, in the form of an aspherical collecting lens.
• the focusing optical system comprising optical element 16 and bottom 12 of the chamber ensures sharp focusing of beam 3 of CW laser 4 required to achieve high brightness of the light source.
• the wavelength of the CW laser Aw is different from wavelengths Xi, X 2 of first and second pulsed laser beams 21, 23.
• dichroic mirror 32 to introduce laser beam 31 of the CW laser and beams 21, 23 of the pulsed lasers.
• a rotating mirror 33, Fig. 5 may also be used.
• the cap of the chamber is equipped with a heater, which includes or consists of, for example, a heating coil 36, a current source 37, which is connected to the former through a temperature bridge 38 intended to provide a temperature difference between heating coil 36 and current-carrying busbars 39.
• currentcarrying busbars 39 may be equipped with a heat exchanger (not shown), for example, in the form of air-cooled radiators.
• Cap 13 of the chamber may also be equipped with a thermocouple 40 to measure the chamber temperature.
• cap 13 of the chamber with heating coil 36 may be placed in a heat-insulating enclosure (not shown).
• Heater 36 is intended for pre-start heating of the chamber up to an operating temperature, that facilitates the starting plasma ignition and ensures fast onset of the steady running mode of the light source with the preset optimally high temperature of the chamber, which is, preferably, in a range of 600 to 900 K.
• the high-brightness light source contains a control unit 41, which incorporates the function of automated maintaining the preset power in beam 7 of plasma radiation directed to the consumer system, Fig. 5.
• the light source is equipped with a power meter 42, to which, using a coupler (not shown), a small part of the luminous flux from beam 7 of plasma radiation directed to the consumer system is supplied.
• the control unit is connected with heater 35, thermocouple 40, power meter 42, pulsed laser system 9, and the power supply unit of CW laser 4.
• the preset power in beam 7 of plasma radiation is maintained by control unit 41 via a feedback circuit between power meter 42 and the power supply unit of CW laser 4.
• control unit 41 may incorporate the function of temperature stabilization of the chamber at an optimally high temperature. In this embodiment of the invention, high stability of power and brightness of the laser-pumped light source is achieved.
• the light source according to the present invention is not limited to this embodiment.
• plasma radiation can be collected by a multichannel optical collector, comprising at least three channels 6a, 6b, 6c, as shown in Fig. 6, where the light source cross-section is located in the horizontal plane passing through radiating plasma region 2.
• the laser beams in Fig. 6, which produce the ignition and maintain the continuous optical discharge, are located below the drawing plane.
• the use of a multichannel optical collector for one light source is required for a number of industrial applications.
• chamber 1 of the laser-pumped plasma light source may be placed in a casing 43, which is equipped with optical collector comprising three channels 6a, 6b, 6c, each of which receives the corresponding parts 5a, 5b, 5c of the beam of plasma radiation.
• the channels 6a, 6b, 6c of optical collector form the beams of plasma radiation 7a, 7b, 7c transferred, for example, via an optical fiber to optical consumer systems 8a, 8b, 8c, which use broadband plasma radiation. This allows for the use of one light source for three and more optical consumer systems, ensuring small size of the system and equivalence of the parameters of broadband plasma radiation in all optical channels.
• the chamber 1 is placed into an external shell 44 with a socket 45.
• the socket may be used to attach chamber 1 and may be partially filled with a sealing material 46.
• the tightly sealed connections are shown in Fig. 7 with solid lines.
• the external shell preferably, has a spherical part with a center in radiating plasma region 2.
• Focusing optical element 16 which, in the particular case, is a lens, is, preferably, also placed into the external shell.
• focusing lens 16 is fixed in a rim 47, which in its turn is fixed, for example, by means of glass fiber reinforced cement or brazing on the nearend part of tube 11 of the chamber 1, Fig. 7.
• the external shell is, preferably, evacuated.
• the external bulb may be made from optical material which incorporates the function of filter cutting off the radiation with wavelengths below 240-260 mm, which produces ozone, i. e. may be used in ozone-free modifications of the laser-pumped light source.
• the proposed invention allows for creating electrode-free high-brightness broadband light sources with highest spatial and power stability and capability of collecting plasma radiation in a solid angle exceeding 9 sr.
• a laser-pumped plasma light source comprising: a chamber filled with high- pressure gas, a means for plasma ignition, a region of radiating plasma sustained in the chamber by a focused beam of a continuous wave (CW) laser, at least one beam of plasma radiation exiting the chamber, means for igniting the plasma, characterized in that the means for plasma ignition is a pulsed laser system generating at least one pulsed laser beam focused in the chamber; the chamber consists of a tube, a bottom and a cap; one end of the tube is hermetically connected to the bottom, while the other end of the tube is hermetically connected to the cap, which is equipped with a gas inlet; the tube and the bottom are made from an optically transparent material; the bottom is arranged for introducing the focused beam of the CW laser and each pulsed laser beam into the chamber
• a laser-pumped plasma light source comprising: the chamber filled with high- pressure gas, the means for plasma ignition, the region of radiating plasma sustained in the chamber by the focused beam of the continuous wave (CW) laser, at least one beam of plasma radiation exiting the chamber, means for igniting the plasma, characterized in that means for plasma ignition is a solid-state laser system that contains a first laser for generating a first laser beam in a Q-switched mode and contains a second laser for generating a second laser beam in a free-running mode the chamber consists of the tube, bottom and cap; one end of the tube is hermetically connected to the bottom, and the other end of the tube is hermetically connected to the cap, which is equipped with a gas inlet; the tube and the bottom of the chamber are made of optically transparent material; the bottom is arranged for introducing the focused beam of the CW laser and each pulsed laser beam into the chamber and the tube, excluding of its end parts, is arranged for the exit of the beam of plasma radiation from the chamber.
• a laser-pumped plasma light source comprising: the chamber filled with high- pressure gas, the region of radiating plasma sustained in the chamber by the focused beam of the continuous wave (CW) laser, at least one beam of plasma radiation exiting the chamber, means for igniting the plasma, characterized in that the means for plasma ignition is a pulsed laser system generating at least one pulsed laser beam focused in the chamber, the chamber consists of the tube, a bottom and a cap; one end of the tube is hermetically connected to the bottom, while the other end of the tube is hermetically connected to the cap, which is equipped with a gas inlet; the tube and the bottom are made from an optically transparent material; the tube and the bottom of the chamber are made of optically transparent material; the bottom is arranged for introducing the focused beam of the CW laser and each pulsed laser beam into the chamber, the tube is arranged for the exit of the beam of plasma radiation from the chamber, and the chamber is located in an external bulb.
• the means for plasma ignition is a pulsed laser system generating at least one pulsed
• High-brightness high-stability laser-pumped plasma light sources designed according to the present invention can be used in a variety of projection systems, for spectrochemical analysis, spectral microanalysis of bio objects in biology and medicine, microcapillary liquid chromatography, for inspection of the optical lithography process, for spectrophotometry and for other purposes.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Plasma & Fusion (AREA)
• Electromagnetism (AREA)
• Plasma Technology (AREA)
• Lasers (AREA)

Applications Claiming Priority (4)

Publications (1)

Family

ID=77358267

Family Applications (1)

Country Status (5)

Families Citing this family (3)

Family Cites Families (16)

• 2021
  • 2021-08-04 EP EP21755458.3A patent/EP4193384A1/de active Pending
  • 2021-08-04 JP JP2023508052A patent/JP2023536367A/ja active Pending
  • 2021-08-04 KR KR1020237007938A patent/KR20230044314A/ko not_active Ceased
  • 2021-08-04 WO PCT/EP2021/071788 patent/WO2022029187A1/en not_active Ceased
  • 2021-08-04 CN CN202180056769.3A patent/CN116235277B/zh active Active
• 2024
  • 2024-02-27 JP JP2024000549U patent/JP3246482U/ja active Active

Also Published As

Similar Documents

Legal Events