Abstract: This invention relates to a laser amplifier system for amplifying a diverged laser beam to very high power levels, at constant flux density, over a very long optical path folded into a compact arrangement consisting of two rows of amplifier segments of progressively increasing diameter, the wide separation between each segment along the optical path being utilized to increase the self-oscillation of the system as a whole. The invention can also utilize only one row of amplifier segments with one or two rows of passive reflectors replacing the other row of amplifier segments, without changing its basic character. The invention is useful in thermonuclear reaction studies and optics studies.

Abstract: Light amplification for use in an optical amplifier or optical resonator can be obtained by exciting cadmium-mercury molecular dimer with an electron beam sustained discharge. Light amplification can also be obtained by exciting a mercury-ammonia complex with an electron beam sustained discharge or with mercury radiation at 2,537 Angstroms produced in an electron beam sustained discharge.

Abstract: A device is disclosed which is capable of amplifying optical signals. The absorptive and dispersive properties of a cavity-enclosed nonlinear medium are combined with the transmission properties of the cavity to yield an input-output characteristic curve that displays gain or bistability.

Abstract: A laser system employs a laser amplifier doped with Neodymium ions having a planar input surface receiving a laser beam having a wavelength of 1.06 microns from a laser generator also employing a Neodymium doped crystal. The laser amplifier provides an output face axially aligned with the input face and having a diameter of approximately one-fifth of the input face diameter. Approximately 88 percent of the axial length of the amplifier crystal is tapered to provide a continuously decreasing cross-section from a point near the input face to a point near the output face and forming a tapered spontaneous pumping zone of substantially reduced diameter adjacent the output face. A special retainer encloses the laser amplifier which direct output pulses from the output face through a bronchoscope to vaporize carbon and possibly other particles located on alveoli within a lung of a living mammal.

Abstract: The invention relates to a laser head and the application thereof to a laser generator device. The laser head comprises in particular a neodymium-doped glass rod, a light excitation source and laser rubies excited by this source, the beams emitted by the laser rubies being returned towards a zone of the glass rod which is insufficiently excited by the light source.

Abstract: 1. A pulsed repeater amplifier circuit comprising three traveling wave tu, each said tube having a helical coil disposed therewithin; an input antenna; an output antenna; means connecting the said antennas and the said tubes in cascade so that a wave received on the input antenna is conducted successively through the said three tubes to the output antenna; means for establishing a predetermined electrostatic field about the helical coil in each tube; and means responsive to an individual modulating signal on the control grid of each tube for amplifying the wave during perdetermined intervals as it travels through each tube.

Abstract: A traveling wave tube (TWT) has a slow wave structure (SWS) which is severed into two or more sections. A signal path, defined below, connects the end of an SWS section to the beginning of the following SWS section. The signal path comprises an impedance matching coupler (IMC), followed by an isolator, a variable phase shifter, and a second IMC. The aggregate band pass characteristic of the components in the signal path is chosen to reject, or strongly attenuate, all frequencies outside the desired operating frequency range of the TWT and yet pass, with minimal attenuation in the forward direction, all frequencies within the desired operating frequency range. The isolator is chosen to reject, or strongly attenuate, waves, of all frequencies, which propagate in the backward direction. The aggregate phase shift characteristic of the components in the signal path is chosen to apply signal power to the beginning of the following SWS section with the phase angle yielding maximum efficiency.

Abstract: The invention relates to a laser generator device emitting at a wavelength of 1.3 microns. This device includes a laser oscillator with a neodymium-doped glass, an iodine gas amplifier disposed at the output of the oscillator and means for causing the emission of the oscillator to take place at a wavelength close to 1.3 microns. Application to the production of plasmas.

Abstract: The invention relates to a gas laser generator. This generator comprises two flat energization lines having the shape of arcs of a half parabola, these lines being in electrical continuity along a common segment connecting the merged focusses of the half parabola arcs and a joint situated near the apexes of the half parabola arcs. Application to nitrogen laser generators.

Abstract: A variable sensitivity monitor circuit changes sensitivity for a period immediately following startup or turnon of the process or equipment being monitored. By changing sensitivity, the monitor circuit will not respond to the transient produced at startup or turnon but will respond to any abnormal condition greater than the transient without any decrease in response time of the monitor circuit.

Abstract: A free jet dye laser having a sheet of fluent laser material bounded along its edges by a pair of opposed guide members. An orifice injects the sheet of laser fluid into the region between the guide members where it flows towards a transparent portion of the guide members through which a beam of laser radiation to be amplified is directed. Pump excitation in the form of laser energy is applied through an exposed surface of the flowing laser material in the region between the transparent portions.

Abstract: A light-amplifying medium is pumped by an auxiliary excitation source and has a number of energy levels, the laser transition being intended to correspond to the laser pulse delivered by the oscillator and to take place between the upper laser level and the lower laser level. Mirrors placed around the amplifying medium reflect the laser pulse from one mirror to the next so that the time interval between two successive pulse traversals within the amplifying medium is longer than the time of population transfer between on the one hand the upper reserve level and the upper laser level and on the other hand the lower laser level and the lower reserve level. The amplifying medium is thus regenerated by population exchange at the lower and upper levels between each pulse traversal through the amplifying medium.

Abstract: An array of field emission cathodes is formed by a plurality of pointed cold cathode elements arranged in rows and columns along microwave transmission means such as a waveguide or transmission line, into which low power microwave energy to be amplified is fed. Arranged opposite the cathode array in spaced relationship therewith is an anode structure. Running along the anode structure is a second microwave transmission means for receiving and coupling out the amplified input energy. Positioned between the anode and the cathode are a plurality of grid members for controlling the electron flow between the cathodes and the anode.

Abstract: An improved laser system and method for implosion of a thermonuclear fuel pellet in which that portion of a laser pulse reflected by the target pellet is utilized in the laser system to initiate a succeeding target implosion, and in which the energy stored in the laser system to amplify the initial laser pulse, but not completely absorbed thereby, is used to amplify succeeding laser pulses initiated by target reflection.

Abstract: Noise in reentrant-stream crossed-field amplifiers is suspected of being generated by electrons re-entering the interaction region with large amplitude cycloidal motion near the slow-wave circuit. Means to increase the electric field in a portion of the drift region preceding the circuit lowers the noise, presumably by collecting these electrons. The field may be increased by decreasing the spacing between cathode and drift electrode or by applying a bias voltage on an insulated electrode.

Abstract: An externally moderated thermal nuclear reactor is disclosed which is designed to provide output power in the form of electromagnetic radiation. The reactor is a gaseous fueled nuclear cavity reactor device which can operate over wide ranges of temperature and pressure, and which includes the capability of processing and recycling waste products such as long-lived transuranium actinides. The primary output of the device may be in the form of coherent radiation, so that the reactor may be utilized as a self-critical nuclear pumped laser.

Abstract: A laser amplifier system is provided for amplifying laser beams of elliptical cross-section which includes one or more amplifying disc segments of circular cross-section, the diameter of these segments being much greater than their thickness and also equal to the major axis of the laser beam cross-section. The segment of circular cross-section is oriented at an angle to the minor axis of the elliptical beam cross-section given by the cosecant of the ratio of minor to major axes of the beam cross-section and symmetric about the axis of propagation of the laser beam.

Abstract: A flashlamp for exciting a laser medium having a vortex stabilized continuous low level DC discharge. The stabilized continuous discharge is periodically pulsed with a high energy discharge to provide pulses of excitation radiation that are focused into the laser medium to promote lasing thereof.

Abstract: A device is disclosed which is capable of amplifying optical signals. The absorptive and dispersive properties of a cavity-enclosed nonlinear medium are combined with the transmission properties of the cavity to yield an input-output characteristic curve that displays gain or bistability.

Abstract: Power laser chain. Two amplifying elements are separated by a linear polarizer placed between two polarization transformers such as a quarter wave plate or a Fresnel parallelepiped, this preventing auto-oscillators in the amplifying chain, it being possible to repeat that sequence several times in the chain.

Abstract: A delay line for traveling-wave tubes, particularly a wideband low-reflection attenuated line for millimeter waves, in the form of a hollow guide having successive transverse walls which define successive line cells, each of such walls having a central opening for the passage of the electron beam and at least one coupling opening, elongated attentuating members being disposed in the respective cells with their longitudinal axes extending parallel to the longitudinal axis of the delay line. The attenuating members are of like effective length and the matching cell lying immediately ahead of and/or behind the attenuating section of the tube contains, in each case, at least one matching member.

Abstract: A circuit to control the RF drive to a gridded traveling wave tube (GTWT) to operate the tube in saturation across the entire RF band and at all PRF's and pulse widths. Control is attained by sensing the GTWT output and using a feedback circuit to vary an input variable attenuator to the GTWT based upon whether the output is increasing or decreasing.

Abstract: An infrared laser system and method for isotope separation may comprise a molecular gas laser oscillator to produce a laser beam at a first wavelength, Raman spin flip means for shifting the laser to a second wavelength, a molecular gas laser amplifier to amplify said second wavelength laser beam to high power, and optical means for directing the second wavelength, high power laser beam against a desired isotope for selective excitation thereof in a mixture with other isotopes. The optical means may include a medium which shifts the second wavelength high power laser beam to a third wavelength, high power laser beam at a wavelength coincidental with a corresponding vibrational state of said isotope and which is different from vibrational states of other isotopes in the gas mixture.

Abstract: Methods and apparatus for directing radiation pulses to a region wherein either a pulse or a substance in the region is adversely affected by the presence of more than a given power density therein. A laser pulse is split into a plurality of portions and each portion is directed along a path of different length to provide in rapid succession a plurality of pulses each having less than the given power density. Each pulse is caused to arrive at the region at an angle differing by at least its divergence angle from the arrival angle of every other pulse (or, if at a smaller angle from another pulse, with opposite polarization therefrom) and at a time enough later than the arrival time of the preceding pulse that the total power density in the region at any instant is less than the given power density. Thus, the effective total power density of the radiation directed through the region may exceed the given power density without adversely affecting any pulse or substance in the region.

Abstract: A remote site optical transponder device which automatically amplifies an incident laser pulse and returns it to its source is described. The device is especially useful in high precision ranging e.g. determining the motion of planets accurately and in tracking space craft. The device is powered by a long life power source and has a steerable laser light collector / transmitter system. Other essential components are a laser amplifier medium whose excitation means is triggered by part of the energy contained in an incident pulse from a laser tracking system and also a reflector.

Abstract: An electric discharge gas dynamic laser in which excitation of one gas species is obtained in a plenum by use of a dc glow discharge. The gas present in the plenum is then accelerated through an array of supersonic nozzles where the laser species is injected and mixed with the primary flow. Energy transfer and lasing occur in the supersonic region of the flow. Brewster-angle windows which extend from 1 to 28 cm downstream from the nozzle exit plane enables a laser cavity or diagnostic apparatus to be positioned at a variable distance downstream from the injection point. The optics may be mounted on a motor-driven translation table so that continuous scans of the region downstream of the nozzle exit plane may be conveniently made. The present facility may easily be operated with a subsonic cavity, with an RF discharge to augment the dc plenum discharge, with all gases premixed, or with any combination of these configurations.

Abstract: Optically pumped laser amplifiers are disclosed. One type of such amplifier utilizes an excitable medium, the atoms, ions or molecules of said medium having well defined energy states including a lowest state, a lower state above said lowest state, and a higher state above said lower state, and a bright pumping light source composed of a radiative substance different from such medium which radiative substance emits energy in a spectral range which can be absorbed by such medium, and wherein the major portion of the energy absorbed by such medium causes transitions of the atoms, ions, or molecules thereof to populate the higher state.

Abstract: The optically pumped submillimeter wave lasers employing molecular gases having dipole moments are improved by employing as a polyatomic buffer gas a molecular gas or vapor of a hydrocarbon having a significantly large vibrational heat capacity in relation to its molecular weight. An example is C.sub.6 H.sub.14 added to such lasers as the methyl fluoride laser at 496 micrometers. Other examples of saturated hydrocarbon buffers are also given; and in each case the vapor molecule is complex enough to absorb many vibrational quanta from the active molecules, yet is small enough to move rapidly to the tube walls.

Abstract: An inert diluent such as N.sub.2, He, Ar, etc., is injected into the reactant streams emerging from the cavity nozzle of a CW, supersonic, laser to increase the cavity power and lower the cavity temperature by enhancing mixing of the reactant stream while maintaining high pressure recovery.

Abstract: An improved laser illuminator for target designation, such as for a target-seeking missile or object in flight or from a tracking target station, that simultaneously provides output pulses of high peak power at a low pulse repetition rate to meet the maximum range requirements of the designation or tracking system and provides output pulses of low peak power at a high pulse repetition rate to provide the high tracking error signal information rates needed at close ranges. The illuminator operates either for active or semi-active guidance of a missile to a target or for tracking an object or target from any suitable station in either an active or semi-active mode. In one arrangement in accordance with the invention, a laser oscillator is controlled in series with an amplifier arrangement to selectively provide the high power and the low power pulses which are transmitted as a common pulse train.

Abstract: An electron bombarded semiconductor amplifier with a simplified target construction where the common point of the diode array is returned to ground enabling the radio frequency bypassing capacitors to be made a smaller size and the dc blocking capacitors to be provided by separate capacitors outside of the vacuum envelope and also optimized.

Abstract: A high voltage glow discharge power source providing a plurality of glow discharges by gas ignition within at least one elongated electrically insulating member having a central bore along the axis of elongation of the member. Electrodes are positioned along the outer surface along the length of the member to which current sources and sinks are connected in alternation. A DC power supply provides the energy for the current sources and sinks. End plates covering the bore are transparent to optical frequencies. Glow discharges occur within the bore so that when a laser generator beam is diverted into the bore through the end plates, the gas in the bore being ignited to provide the glow, discharges and effects a power gain in the laser signal at the other end of the bore.

Abstract: A system for phase control of multiple high power microwave frequency amplifiers. A pilot frequency lower than the frequency to be amplified is used to modulate the microwave signal. The pilot frequency is detected at the output of the amplifier stage and phase compared with the original pilot frequency. Any difference is used to produce a phase correction signal applied to the amplifier. Phase modulatable traveling wave tubes are the power amplifiers. One alternate embodiment involves a steerable array employing an additional pilot frequency correction introduced into the pilot signal. In another embodiment a cross field amplifier is placed in series with a traveling wave tube amplifier in the phase correction loop.

Abstract: A uni-directional laser amplifier system including a diverged beam having either a single unstructured pulse or a train of such pulses amplified to a very high power level over a long, folded amplification path. The beam emerges via a large, elliptical, cross-section aperture. The system includes two spaced rows of amplifying segments of elliptical and progressively increasing cross-sectional area with each segment having two polished non-parallel flat end surfaces with the front surface of each being anti-reflection coated and the rear surface having a laser mirror attached thereto or separated in conjunction with it by at least half the length of the laser pulse to be amplified. The segments are oriented an an angle of approximately 45.degree. to the length of its row and at an angle of about 90.degree.

Abstract: A luminosity control device comprises a first semiconductor laser operable in a spontaneous mode to emit noncoherent light and in a laser mode different from its inherent laser mode to emit coherent light. The first semiconductor laser is electrically biased into its spontaneous laser mode. A second semiconductor laser is operated in a laser mode to emit coherent light which is applied to the first semiconductor laser to optically bias the first semiconductor laser into the laser mode of the second semiconductor laser. The second semiconductor laser is electrically biased into operating in its laser mode and the optical coupling between the two semiconductor lasers is such that the coherent light output from the first semiconductor laser varies exponentially with respect to the electrical energy input into the second semiconductor laser.

Abstract: A method for producing stimulated emission of radiation in the X-ray region comprising the steps of: selecting as an active medium a system having the following properties; two energy levels separated by an energy difference .DELTA.E corresponding to radiation of frequency .omega..sub.t in the X-ray region such that a transition from the upper to the lower of the two levels by one-photon emission is weakly allowed or strictly forbidden, one of the two levels having a nearly degenerate partner level optically coupled thereto such that a transistion therebetween by one-photon emission has a high probability; providing a resonator containing such an active medium; subjecting the active medium in the resonator to stimulating radiation at a frequency .omega..sub.1 that is preferably, substantially equal to the frequency of the optical coupling between the nearly degenerate levels but much smaller than the frequency .omega..sub.

Abstract: An electrodeless RF excited gas arc lamp for pumping a laser has a lamp envelope in the form of a loop having a continuous bore containing krypton, xenon or argon. Sufficient RF power to maintain a plasma in the gas in the loop is provided by a coil around its circumference so that it is linked by the flux generated by RF voltage through the coil. The laser rod to be pumped is mounted adjacent the loop. A diffuse reflector surrounds the lamp and laser rod to reflect back toward the rod light which does not impinge directly on the rod as well as any impinging light not initially absorbed by the rod.

Abstract: A laser device has a plasma discharge region for dissociating a diatomic gas into atoms. A nozzle connects the plasma discharge region with an optical cavity. The nozzle expands the plasma accelerating it to a supersonic velocity as it passes from the discharge region into the optical cavity. As the plasma passes through the nozzle, the dissociated atoms are recombined into molecules in a metastable energy state. The nozzle includes a gas injector for introducing a lasing gas into the plasma flow through the nozzle.

Abstract: A chemical laser having means for repeatedly circulating the gaseous working medium in a portable, self-contained system is disclosed. An excited laser species is formed by chemical means and after passing through the optical cavity, the working medium is purified by selective absorption and adsorption processes, increased in pressure, supplemented with makeup feed reactants and recycled. The operation of a system using deuterium and sulfur hexafluoride gases is discussed in detail although various combinations of other suitable reactants which provide a halogen and hydrogen or an isotope thereof are disclosed.

Abstract: The invention concerns a vibration energy transfer laser. Vibration energy which is transferred by molecular interaction to bromhydric acid which can then produce infra-red light by stimulated emission, is imparted to nitrogen. Application to the transmission of light through the atmosphere.

Abstract: A highly efficient, compact pulsed laser having high energy to weight and volume ratios is provided. The laser utilizes a cavity reflector that operates as a heat sink and is essentially characterized by having a high heat conductivity, by being a good electrical insulator and by being substantially immune to the deleterious effects of ultra-violet radiation. Manual portability is accomplished by eliminating entirely any need for a conventional circulating fluid cooling system.

Abstract: A high voltage glow discharge power source providing a plurality of glow discharges by gas ignition within an first elongated member, which member has a central bore along the axis of elongation of the member. A second member used in an E-gun application having a cavity with a soft vacuum in the cavity, and a third similar member parallel to the second member and a common interface boundary between the second and third members. Electrodes are positioned along the outer surface along the length of the first member to which current sources and sinks are connected in alternation. The second member has a common wire running its length with auxiliary wires connected to the common wire which are connected in turn to the sources and sinks. A DC power supply provides the energy for the current sources and sinks used with the first member. End plates covering the bore of the first member are transparent to optical frequencies.

Abstract: Optical radiation generation and detection using metal-to-metal diode junctions. Coherent optical radiation is generated by using an antenna connected to a metal-to-metal diode junction with non-linear current-voltage characteristics and by coupling to the junction electromagnetic radiation energy to interact with the junction, causing emission from the antenna at optical frequency absent from the input. Optical diodes are shown in the forms of a mechanically contacted cat whisker system and as single and multiple microscopic solid portions in an integrated solid mass, defining both the antenna and the junction, preferably as a deposit of solid layers upon a substrate, preferably as overlapping printed circuit line structures. Arrays of such junctions provide enhanced effects; useful arrays include Franklin-Marconi geometries, fish-bone antennas and row and column arrays.

Abstract: A laser amplification method for increasing the energy extraction efficiency from laser amplifiers while reducing the energy flux that passes through a flux limited system which includes apparatus for decomposing a linearly polarized light beam into multiple components, passing the components through an amplifier in delayed time sequence and recombining the amplified components into an in phase linearly polarized beam.

Abstract: There is disclosed a gaseous laser, whose cathode is a conductive coating upon the walls of a cathode volume, the geometric design of the cathode, cathode volume, and cathode-connecting volume being such as to impede sputtering of the cathode.

Abstract: An electron beam deflection amplifier having two spaced parallel electron ams and a pair of spaced collector electrodes for intercepting the beams to provide an output beam current. The beams are deflected in opposite directions by the input signal to be amplified but are deflected in the same direction by external undesired stray fields. The collector electrodes are dimensioned and relatively positioned such that variable portions of both beams will be collected at both electrodes. Each collector electrode will intercept a portion of each beam and the portion of each beam not intercepted by one collector electrode will be intercepted by the other collector electrode. For desired input signals, the collector current outputs are additive. A stray magnetic field will deflect the electron beams in the same direction in which case the output current due to one beam substracts and cancels the output current from the other beam. In this manner the effect of external fields are compensated for and nullified.

Abstract: A system for optically coupling an intense photon output from an explosively shock-heated gas to a laser amplifier for the generation of a very high power optical pulse. A laser amplifier element preferably a dye laser type is centrally located within and supported by an enclosed hexahedron housing filled with a visible or infrared absorbing solution. Each leg of the hexahedron has secured thereto a pyramidal shaped (a pyramid with the apex end cut off parallel with the base) gas filled lamp for pumping the laser amplifier element. Each gas lamp is provided with a liner of explosive material along the inside of the outermost surface which is ignited by an electrical detonator. Detonation of the explosive liner produces an imploding shock wave which raises the argon gas to incandescence to excite the liquid dye laser amplifier to produce a population inversion necessary for laser amplification.

Abstract: A laserable material with a host of non-gaseous, non-periodic atomic structure is provided. The host material is plastic and dispersed in solid solution within the plastic is a chelate of a rate earth metal. The material exhibits narrow-line fluorescence when excited by a high energy light source.

Abstract: A low pressure gas laser is provided with an aerodynamic window for the generated high power laser beam. The window comprises a duct with an oblique opening located in the supersonic part of and aligned with the axis of a Laval nozzle, having an atmospheric entrance. This permits extraction of the beam from the laser without any contact through a solid window.

Abstract: In a high-power laser system it is proposed that combustion or compressor gases be diverted from the normal flow path through a gas turbine engine into an auxiliary flowpath, and that their composition be subsequently adjusted by burning at least one hydrocarbon fuel in them and possibly also by adding other fuels and substances. Suitable aerodynamic expansion of the resultant gases produces a population inversion in the CO.sub.2 species, which can be utilized in a laser.