RussianPatents.com

Method and device for producing laser beam. RU patent 2244990.

FIELD: pulse-periodic lasers pumped with self-maintained spatial discharge.

SUBSTANCE: proposed method used for producing beam from pulse-periodic laser pumped with self-maintained spatial discharge with XeXl, KrF, CO₂, and HF base active means includes formation of at least one electrode of a number of plasma generations near effective surface with self-maintained spatial discharge producing repetitive plasma structure and generation of laser beam. Plasma generations are formed in any plane perpendicular to optical axis of laser near effective surface of at least one of electrodes, its size being smaller than maximal size of plasma generation at one repetition period of plasma structure and smaller than or equal to size of laser radiation beam produced in same plane near effective surface of mentioned electrode. Device implementing this method has at least two opposing electrodes connected to common buses of pumping source and optical cavity; at least one of electrodes is made of repetitive parts each having its respective effective surface. Repetitive electrode parts are installed either in planes parallel to optical axis of laser or in those disposed at acute angle to this axis, or in cylindrical surfaces with generating lines perpendicular to optical axis of laser and guides of these surfaces in the form of curves or broken lines. Such design ensures desired energy distribution for various processes.

EFFECT: minimized divergence of laser beam, enhanced repetition rate of laser pulses in different ranges of laser beam spectrum, reduced power requirement for pumping laser mixture.

19 cl, 17 dwg

IPC classes for russian patent Method and device for producing laser beam. RU patent 2244990. (RU 2244990):

H01S3/097 - Lasers, i.e. devices for generation, amplification, modulation, demodulation, or frequency-changing, using stimulated emission, of infra-red, visible, or ultra-violet waves (semiconductor lasers H01S0005000000)

H01S3/038 -

Another patents in same IPC classes:

High-frequency excited co<sub>2</sub> waveguide laser

High-frequency excited co₂ waveguide laser / 2244367
Proposed laser has two channels of which first one functions as discharge channel, as well as high-reflection and light-splitting mirrors installed at ends of discharge channel. Each channel is bound on opposite ends with extreme and central electrodes and on two other ends, with insulating wafers. One of extreme electrodes has rectangular longitudinal slot of depth L ≥ 1.5h and width H ≥ h + 1 to form insulating space together with closest second channel holding additional working gas supply, where h is discharge channel width.

Method and device for producing laser beam / 2244990
Proposed method used for producing beam from pulse-periodic laser pumped with self-maintained spatial discharge with XeXl, KrF, CO2, and HF base active means includes formation of at least one electrode of a number of plasma generations near effective surface with self-maintained spatial discharge producing repetitive plasma structure and generation of laser beam. Plasma generations are formed in any plane perpendicular to optical axis of laser near effective surface of at least one of electrodes, its size being smaller than maximal size of plasma generation at one repetition period of plasma structure and smaller than or equal to size of laser radiation beam produced in same plane near effective surface of mentioned electrode. Device implementing this method has at least two opposing electrodes connected to common buses of pumping source and optical cavity; at least one of electrodes is made of repetitive parts each having its respective effective surface. Repetitive electrode parts are installed either in planes parallel to optical axis of laser or in those disposed at acute angle to this axis, or in cylindrical surfaces with generating lines perpendicular to optical axis of laser and guides of these surfaces in the form of curves or broken lines. Such design ensures desired energy distribution for various processes.

Excimer laser / 2249282
Proposed excimer laser that can be used for intracavitary therapy in medicine, for microelectronics, laser chemistry, and processes using heavy-power ultraviolet rays has electrode system, pulse power circuit with storage capacitor, and switch in the form of thyratron. Electrode system has insulating plate that carries electrodes; thyratron is connected in series with storage capacitor and electrode system. Electrode system is designed to ensure pumping of excimer gas medium with discharge creeping over insulating plate surface.

High-frequency discharge excited gas laser / 2411619
Transverse pumped gas laser has a housing, an optical resonator, an electrode connected to a resonance-tuned high-frequency power supply, a cooling heat exchanger and a centrifugal compressor. The housing is formed by an outer cylindrical metal casing and an inner cylindrical dielectric casing placed eccentrically inside the said outer casing, hermetically joined to front flanges and forming a gas-dynamic channel for circulating the active medium. The centrifugal compressor creates a stream of gaseous medium which envelopes the inner cylindrical dielectric casing. The section of the gas-dynamic channel with the narrowest cross section forms a plasma chamber and has a symmetrical or asymmetrical profile which varies on the height and has an arc-like or flat shape with angular opening in the direction of flow of the active medium along the width of the zone of the optical resonator. The electrode adjoins the outer surface of the inner cylindrical dielectric casing with its surface. The inner surface of the outer cylindrical casing on the said section of the gas-dynamic channel is insulated from the gas stream and the plasma by a dielectric layer, and the outer cylindrical metal casing is earthed.

Pulse-periodic te-laser / 2419933
Laser includes gas-filled chamber with the main discharge electrodes installed in it, charging circuit and discharging circuit. Charging circuit includes pulse voltage source and peaking capacitors. Discharging circuit includes peaking capacitors and the main discharge electrodes, at least one corona pre-ioniser in the form of dielectric tube with inner and outer electrodes. Outer electrode of pre-ioniser covers part of surface of dielectric tube and is connected to the main discharge electrode. At that, outer electrode of corona pre-ioniser is current lead of charging circuit.

Method to stabilise volume charge in hf/df pulse-periodic chemical laser / 2465697
Method includes supply of pulse voltage to barrier electrodes joined with metal electrodes. Pulse voltage is supplied at current density of volume phase of discharge of at least 1 kA/cm2 to barrier electrodes, having semiconductor properties, combining active and capacitance resistances. Active resistance is determined by volume resistance of barrier electrode material equal to 48 - 52 Ohm·cm, and capacitance resistance is determined by the value of relative dielectric permeability of barrier electrode material equal to 1800 - 2200.

Two-dimensional intracavity radiation scanning gas laser / 2477913
Gas laser has a system for high-frequency excitation of the active medium with a scanning device, having two metal disc electrodes, one of which on the side of the interelectrode space is coated by a dielectric layer which current-conducting wedge-like metal tracks are deposited. The laser optical cavity is formed by two circular annular mirrors. On one half of the perimeter of the mirror, the coating provides partial reflection, and the other half of the surface of the circular annular mirror (3) is in form of an orthogonal array composed of n×m controlled mirrors (5), having a coating with a controlled reflection coefficient (6) such that the form of the common surface of the array repeats the form of half of the surface of the annular mirror which partially transmits radiation. There are additional actuating elements (19) in amount of n×m per controlled mirror of the array and an electronic switch (20) for elevation-angle deviation of output radiation which carries the deviation signal to the ij-th actuating element (19) for changing the reflection coefficient of the ij-th controlled mirror (1≤i≤m, 1≤j≤n) to a value closer to one.

Apparatus for generating volumetric self-sustained discharge / 2517796
Apparatus for generating volumetric self-sustained discharge has a discharge chamber in which are mounted three electrode pairs which are connected to a pumping source, each pair consisting of plate-like profiled electrodes. Each cathode plate is situated in the plane of the corresponding anode plate and electrode pairs are mounted either parallel to the longitudinal axis of the chamber or at an acute angle to said axis. The working edge of the central cathode plates has at the centre a straight portion to which portions with a Stepperch profile adjoin at both sides. The working edge of the central anode plates has an arched shape and faces the discharge gap with its convex surface. Portions of the working edges of the outermost anode and cathode plates, facing the centre electrodes, repeat the profile of the working edge of corresponding anode and cathode central plates. Outer portions of working edges of the outermost anode and cathode plates have an arched shape and a longer length than portions of working edges of the outermost anode and cathode plates facing the centre electrodes, wherein all portions of the working edges have smooth mating.

Apparatus for exciting spatial charge in dense gases / 2519657
Invention relates to quantum electronics and can be used to excite active media of gas lasers. The apparatus for exciting spatial charge in dense gases includes a high-voltage source connected to elongated, blade-shaped corona and current-collecting electrodes mounted along a dielectric cylinder which is capable of rotating. An electroconductive screen and a dielectric film are placed on the outer surface of the cylinder, wherein the corona electrode is placed along the radius of the cylinder with spacing from the cylinder. The screen is in form of two or more sections extending along the cylinder and electrically insulated from each other, wherein the section passing through the zone of the blade-shaped corona electrode is connected by a sliding contact to the grounded terminal of the source, and the section pass through the zone of the blade-shaped current-conducting electrode is connected by a sliding contact to the potential terminal of the source. Potential applied to a section of the screen can be controlled, for example, by a potentiometer.

Method and device for exciting self-restrained and self-heated metal atom junction pulsing lasers / 2251179
Proposed method includes generation of one additional delay pulse with each drive pulse at certain delay between pulses and constant energy insertion in laser active element. Lasing power characteristics at stabilized parameters of plasma are controlled by momentum changes of additional pulse location relative to drive pulse. For lasing mode additional pulse is generated past main drive pulse and for lasing pulse suppression mode it is produced in advance of main drive pulse; in this case energy of additional pulse should be sufficient only for populating metastable laser levels of metal atoms. Pulse advance time and pulse delay time of additional pulse counted from origin of drive pulse should be lower than lifetime of metastable laser levels. Stabilization of plasma parameters is additionally corrected by varying advance time and delay time of additional pulse with respect to drive pulse. Device implementing this method has laser tube whose cathode and grounded anode are shorted out by inductance coil; resonator; two switches; two energy storage capacitors whose leads are integrated and connected to laser tube cathode; adjustable high-voltage power supply whose common lead is connected to grounded cathodes of switches; trigger pulse generator; two adjustable delay lines; two anode reactors; two pulse modulator drivers; nonadjustable delay line; electronic relay; controller.

Space-saving pulsed gas laser and magnetic pulse compressing device for its excitation / 2254650
Proposed laser has coaxial sectionalized discharge cell forming low-inductance power transmission line with pulse shaping circuit connected to central electrode, and thyratron placed in conducting shell which is part of common low-inductance power transmission line. Pulse shaping circuit made in the form of magnetic pulse compressing device has saturating reactors inductively and capacitively coupled with discharge tube mounted in magnetic pulse compressing device. Laser has coaxial sectionalized discharge cell with gas gap between plates. Gas gap thickness to discharge tube wall thickness ratio is higher than dielectric constant of discharge tube material. Sheet-steel ballast capacitors are disposed coaxially to discharge cell and symmetrically to magnetic pulse compressing device. The latter uses parallel circuit arrangement for connecting magnetic compression power lines. Each line incorporates additional saturating reactor in first section. Parallel-connected to ground are limiting saturating reactor and peaking capacitor.

Chemical element vapor pulse-periodic laser / 2254651
Proposed laser has gas-discharge tube, high-voltage rectifier, resonant charging choke, charging diode, storage capacitor, thyratron, generator, feed-through capacitor, negative bias source, and power supply. Gas-discharge tube is placed in cavity. High-voltage rectifier is coupled through one of its outputs witch input of resonant charging choke. Generator output is electrically connected via feed-through capacitor to gate electrode that functions as thyratron grid. Negative bias source is connected to gate electrode. High-voltage rectifier is coupled through its other output with storage capacitor. Second lead of the latter is connected through charging diode to output of resonant charging choke. Common generator output is connected to thyratron cathode. Thyratron anode is electrically connected to storage capacitor and to charging diode. Thyratron cathode is coupled with gas-discharge tube anode and has decoupling filter and two storage capacitors. Decoupling filter is made in the form of two inductance coils.

Method and device for exciting gas molecules and atoms / 2255398
Proposed method intended for exciting molecules and atoms of working gas includes voltage supply to electrodes and organization of working gas flow in discharge gap so that working gas flow is fully passed through cathode layer of volume glow discharge; gas flow organizing means is disposed upstream of cathode so that gas mixture flow is passed through cathode , interelectrode space, anode, and radiation generation working area. Device implementing this method has flow organizing means, power supply, working gas, and discharge chamber incorporating anode and cathode made in the form of grids; at least cathode grid has regular pitch not to exceed thickness of cathode layer of normal gas volume glow discharge; peripheral regions of device electrodes are separated and protected against breakdown by means of electric insulator; flow organizing means is disposed upstream of cathode.

Method for transmitting optical pulses / 2262199
Method for transferring optical pulses by several laser beams includes forming a central laser beam and cover around it in form of tunnel. Tunnel is formed by one beam or a set of beams, contacting each other. Tunnel is made also with possible rotation relatively to central beam and consists of two portions, formed by set of oppositely directed beams.

Method and device for forming powerful laser pulse / 2267197
Method and device can be used at powerful multichannel laser installations with radiation power level higher than 1012 W. Operation of laser is based upon forming of partially coherent laser pulse. Characteristics of laser pulse are specified by design mutual coherence function. Values of the function are necessary and sufficient for optimal matching of laser-target system. Device for forming powerful laser pulse has master oscillator, system for forming space-time characteristics of laser pulse and amplifiers. Amplifiers are disposed in sequence along rising cross-section of beam to be amplified correspondingly to space-angle distribution of radiation intensity. Distribution is matched with design function of mutual coherence. High uniformity intensity distribution is provided in focus of laser.

Scheme of excitation of lasers on metal fume / 2269850
The scheme has n modules linked up to a power source through a charging inductance. Each module has one section of a multisectional high frequency transformer. Each section of the transformer has two primary windings coiled back-to-back and one secondary winding. Each module has also two accumulative condensers, two charging diodes and twp transistor commutators. The accumulative condenser is charged through a corresponding charging diode and a charging inductance from the power source and is discharged through corresponding transistor commutators and primary windings of the section of the multisectional transformer. The shutters of the transistor commutators are linked up through devices matching with the scheme of the starting. The secondary windings of all sections of the multisectional transformer are successively connected and linked up to the outputs of the gas discharge tube.