Abstract: Free electrons laser with gaseous medium wiggler and method to use this laser. The laser includes a chamber (22) designed to be traversed by a beam of previously accelerated electrons, a wiggler (44) which creates in this chamber a periodic magnetic field interacting with the beam of electrons, and means (54) to fill the chamber with a gas formed of atoms or molecules having at least one resonance line at a determined frequency. The laser is tuned on this resonance line, which enables the laser to produce a frequency light close to this determined frequency.

Abstract: To produce a medium for the emission of coherent radiation, i.e., a laser-active medium, using a complex of metastable helium and ammonia, it is proposed that it comprise a complex of metastable helium and ammonia as well as a radiation-active component, that the complex and the radiation-active component both be in the condensed, solid phase, and that the complex be present in the laser-active medium in condensed form with its dipole moment aligned substantially in one direction.

Abstract: A method for the frequency stabilization of a laser oscillated from an internal mirror type helium-neon laser device and having an oscillation wavelength of 543 nm is disclosed, wherein a static magnetic field satisfying the following conditions (1)-(3):(1) the direction of the static magnetic field is perpendicular to the axis of the capillary tube and the angle between the direction of the static magnetic field and the direction of a characteristic polarization of the laser tube is equal to 30.degree.-42.degree.;(2) the magnitude of the static magnetic field is such that each Zeeman frequency in .pi. and .+-..sigma. transitions equals an axial mode spacing when the static magnetic field is applied into the laser capillary; and(3) the magnitude of the static magnetic field is almost even along the longitudinal direction of the laser capillary,is applied into a laser capillary so as to prevent polarization flipping.

Abstract: A stabilized helium-neon laser emits radiation in the ranges of ultra-violet, infra-red and visible other than red in at least two modes. A stabilizing system consists of an alignment heater (19) which bends the laser tubes toward optimum alignment, a coil heater (20) which cyclically varies the tube length and permanent magnets (24,25) which reduce instability of mode polarizations and to optimize relative intensities of the modes. The transmitted output is stabilized in frequency by control of the laser tube length, with the stabilization signal derived from the steady or varying intensity of intensities of one or both of two orthogonally polarized optical outputs. There are many potential uses for non-red helium-neon lasers in applications where non-red light is required, for example, in multi-wavelength interferometry.

Abstract: Efficient impedance-matched gas laser excitation circuits integrally employ prepulse power generators. Magnetic switches are employed to both generate the prepulse and switch the prepulse onto the laser electrodes.

Abstract: A tunable laser includes a laser medium (24), a resonant cavity (27, 28), at least one Faraday rotation element (26), and a polarization sensitive attenuator (25). Waves of laser energy produced by the laser medium resonate in the resonant cavity between a 100% reflective surface (27) and a partially transmitting mirror surface (28). The waves pass through the attenuator (25) and are linearly polarized. The linearly polarized waves pass through the Faraday rotation element (26) and the polarization sensitive attenuator (25) on each pass through the resonant cavity. The Faraday rotation element includes a permanent magnet (54) and a trim coil (56) for generating both fixed and variable components of a magnetic field. The polarized wave is rotated by an amount proportional to the intensity of the total magnetic field and the wavelength of the polarized wave. The polarization sensitive attenuator allows only waves of a prescribed polarization angle to pass therethrough without attenuation.

Abstract: An ion laser is constructed with means for generating a magnetic confinement field operating in the cathode transition region of the laser. The magnetic confinement field is preferably generated by first and second magnetic windings, each axially aligned with the laser volume, but disposed so as to generate first and second magnetic fields which are of opposite polarity. The first and second magnetic fields of opposite polarity combine to create a region of zero axial magnetic field, which in a preferred embodiment is located substantially within the cathode transition region of the laser. In an alternate embodiment, the first and second magnetic fields are of the same polarity, and therefore generate a region of minimized axial magnetic field, preferably located substantially within the cathode transition region of the laser.

Abstract: An improved free electron laser is described. The laser comprises an accelerator arranged in order to emit an electron beam along a laser emission line and a circuit loop including a curved line which traces a periodic function along a line parallel with said laser emission line in order to produce a periodic magnetic field along said laser emission line. The periodical circuit is made of a superconducting material, so that the periodical length thereof is made as short as 100 microns without compromising the strength of the magnetic field induced by the circuit.

Abstract: A green diamond has a nitrogen content in its crystals within the range of 5.times.10.sup.16 to 3.times.10.sup.19 atoms/cm.sup.3, an absorption coefficient of H2 centers at a wavelength of 800 nm within the range of 0.3 to 6 cm.sup.-1, an absorption coefficient of the Ib type nitrogen at a wavelength of 500 nm within the range of 0.05 to 1.5 cm.sup.-1, and absorption coefficients of H3 centers, H4 centers, N-V centers and GR1 centers in the visible region of not more than 0.2 cm.sup.-1. Such green diamonds are produced by preparing a clear-yellow Ib type diamond having a nitrogen content in crystals within the range of 5.times.10.sup.16 to 3.times.10.sup.19 atoms/cm.sup.3, irradiating this diamond with an electron beam having not less than 1.times.10.sup.18 electrons/cm.sup.2 at an accelerating voltage of 2 to 4 MeV, and subjecting the diamond to a heat treatment at a temperature of 1500.degree. C.-1800.degree. C. in a vacuum of not more than 10.sup.-3 torr.

Abstract: A modified laser tube including a second pinch off tube or port for flowing argon and krypton gas through the laser for processing to remove contaminants to improve performance of new and used tubes such as ALC 60X argon ion lasers. Lasing discharge is maintained during processing to release contaminants for removal by plasma scrubbing of the laser bore. A magnetic field is applied and rotated in a plane perpendicular to the laser during discharge to enhance contamination release during plasma scrubbing. Preliminary cathode activation, control of gas flow rates and tube power as well as alternating of argon and krypton gas controls the contaminant release rate to prevent recontamination of the laser by released contaminants before removal.

Abstract: An optical pickup apparatus is disclosed which comprises an optical detector formed on a substrate for detecting light reflected by a recording medium, a pattern formed on the substrate, a first block on which the substrate is fixed, a first reference surface formed on the first block substantially in parallel with an optical axis of the light to be detected, a second block arranged to be movable so as to be adjusted in a plane perpendicular to the optical axis and to support the first block, a second reference surface formed on the second block so as to correspondingly contact with the first reference surface; and a relay substrate fixed on the second block and electrically connected to the pattern.

Abstract: An unstable ring resonator employing grazing incidence telescopic mirrors to expand a high power laser beam after it emerges from the wiggler. The grazing incidence mirror is used to increase the footprint of the laser beam on the mirrors surface to decrease the laser's intensity on the surface of the mirror, and thus increase the power of the laser which can be handled in a ring resonator. The ring resonator consists of a scraper mirror 12, a turning mirror 13, a grazing incident beam reduction telescope 101 comprising mirror components 1 and 2, a wiggler 4, a grazing incident beam expansion telescope 102 comprising mirror components 6 and 7 and a second turning mirror 14. The grazing incident telescopes can have mirror components which are of the cone/cone, hyperbola/parabola, cylinder/cylinder or hyperboloid/paraboloid type. The telescopes may also have three or more optical elements.

Abstract: A cyclotron autoresonance maser includes an evacuated drift tube with a first end, a second end and an axis. An electron gun introduces a beam of relativistic electrons to the drift tube first end and, for example, a wiggler magnet causes the electrons to gyrate with the gyrations having relatively small radii. A magnetic field generator is provided which forces the beam of relativistic, gyrating electrons to spiral about the axis of the drift tube. The radii of the spirals is large relative to the radii of the gyrations so that the effective interaction length of the electron beam and a maser beam, having an axis substantially coincidental with the axis of the electron beam, is substantially greater than that of a relativistic electron beam and a maser beam which simply cross. A method of generating coherent radiation is also disclosed.

Abstract: The present invention relates to an analog frequency modulatable laser. The radiation of the lasing medium is analog frequency modulated by change of the optical path length by movement of reflective mirrors forming the resonant cavity at the frequency of radiation of the laser in a manner corresponding to an information signal. In one embodiment, a magnetostrictive material is deposited on and bonded to the outer periphery of an active lasing medium having appropriate mirrors on the ends thereof. The magnetostrictive material is exposed to an information encoded magnetic field and physically expands or contracts the physical length of the lasing medium along the optical axis of the lasing medium corresponding to the modulated information of the magnetic field.

Abstract: The generation of soft x-ray and/or extreme untraviolet laser radiation is accomplished in a capillary plasma generated by a fast discharge. The method yields laser action at short wavelengths in a discharge created plasma having a large length-to-diameter ratio.

Abstract: An approach is shown for eliminating the expense of a plurality of linear accelerators as used in a multiple electron beams free electron laser system. A single linear accelerator is used to simultaneously accelerate a plurality of electron beams by using an electron beam deflection means such as a bending magnet to cause multiple beams to converge to a single stream of electrons for acceleration by the linear accelerator and then using a similar beam deflection means to re-define the accelerated beams in accordance with their repsective enery levels into a similar plurality of output beams.

Abstract: The invention relates to improved gas lasers with an increased power output compared with conventional lasers of a similar size. There is established an axial magnetic field and an electric field either parallel therewith or perpendicular thereto, the interaction of such fields resulting in a substantially increased convective instability of the gas discharge, resulting in an increased heat transfer to the walls of the laser. The laser discharge is in the axial direction parallel with the magnetic field. The components of the laser, except for the means of establishing such magnetic and electric fields of predetermined strength, are of a conventional nature. The invention further relates to a method of operating a gas discharge laser in such a manner that there is established an axial magnetic field and an electric one either orthogonal or parallel therewith, resulting in a strong convection, heat transfer to the walls and dramatically increased power output.

Abstract: An improved drive coupling and bearing assembly for a recirculation fan in a long-life gas laser unit includes a plurality of frictionless gas bearings which allow journals supporting the recirculation fan to ride on a cushion of compressed laser gas. Mechanical power is transmitted from an external source to the recirculation fan through a magnetic coupling assembly, so that the walls of the sealed laser unit do not have to be breached. Additional structure is provided for spacing the driven magnet in the magnetic coupling assembly from the interior wall of the long-life laser unit.

Abstract: Path length error is computed from the output frequencies for the two states of magnetization of the magnetic mirror. The path length error signal is used to adjust the location of a path length control mirror to drive the path length error signal to zero. A table is provided for computing the path length control error signal for different regions in the graph of frequency versus gyro angular rate. In effect, the error signal is the difference between a reference frequency which depends on the temperature of the laser structure and an average of the output frequencies corresponding to the two magnetization states of the magnetic mirror.

Abstract: An optimized design for a resonator for a laser housing and assembly is disclosed, comprising a concentrically arranged plasma tube, magnet and resonator tube with the mirrors and associated optics housed at opposing ends of the resonator tube, mounted on rods extending from respective ends of the resonator tube.

Abstract: A free-electron laser has a wiggler for a linear electron beam comprising two sets of magnetic polepieces 26, 28 periodically spaced along opposite sides of the beam. The polepieces of one set 28 are displaced along the beam from the other set 26 by one-half period. A uniform longitudinal magnetomotive force generates fields between polepieces having transverse components 22 alternating between the sets 26, 28, providing a very short periodicity and hence, high frequency wave radiation.

Abstract: A static periodic field device for a free electron laser has a plurality of holes therethrough to allow the interaction of electrons flowing therethrough to interact with either an electric or a magnetic fields as desired. The device is composed of a plurality of conducting layers separated by insulating layers and appropriately connected to provide either an electric or a magnetic field therein. The separation of the conducting layers determines the raidated energy wavelength.

Abstract: A laser system having a high power output and a large volume gaseous discharge has a plurality of electrodes at each end of a channel to establish a plurality of discharges and a housing arranged to provide a continuous recirculating lasing gas flow through the channel. An ejector connected to a main circulating pump is fixed to discharge into the recirculating lasing gas flow adjacent the channel to mix lasing gas streams and cause diffusion of the gas and thereby provide a uniform plasma flow in the channel. In one embodiment, magnets are arranged to surround the channel to eliminate thermal instabilities, if they arise, and to further homogenize the lasing gas streams and insure their uniformity.

Abstract: An ion laser includes a magnetic field source to generate an axial magnetic field in one region and transverse field components outside the region, the magnetic field source being shorter than the discharge channel of the laser. Axially spaced permanent magnets in the proximity of the discharge channel are adapted to the laser structure and can include magnetic rings or ring structures. The magnets are preferrably adjacent the cathode end of the discharge channel.

Abstract: Light relative to non-modulated output light emitted from a semiconductor laser is applied to an absorption cell. Frequency modulating signals are converted into amplitude modulation signals of the output light through a modulating means by utilizing absorptive properties of the absorption cell. Transmissive light outputs of the absorption cell are synchronously rectified by a lock in amplifier, and an electric current supplied to the semiconductor laser is controlled so that the output signals of the lock in amplifier are arranged to be a predetermined value. The wavelength of the output light is locked to the absorption line of the standard substance in the absorption cell. Advantageously, the invention stabilizes the instantaneous value of the oscillation frequency.

Abstract: An energy generator (10) that converts matter in the form of a gas into an energy source. The generator functions by injecting a gas, such as hydrogen, into a confined chamber (12). The chamber includes an annular permanent magnet (30) and a rotating magnetic assembly (32) that includes a plurality of magnetic fins (36) that form a funnel shape. The combination of the magnets (30), (36) serves to accelerate and centrifugally confine and cause the gas molecules to collide with one another until they acquire sufficient energy to cause lasing.

Abstract: An optical resonator, preferably of a solid state laser, is tuned by one or more sheets of piezo-electric material bonded to one or more tuning facets of an optically transparent solid state member portion of the resonator. A tuning voltage applied across the piezo-electric sheet tends to change the area of the bonded interface of the sheet to generate a set of tuning forces predominantly in the plane of the surface of the tuning facet. These tuning forces are transmitted through the tuning facet into the solid state portion of the optical resonator to produce a change in its refractive index and dimensional change which tunes the frequency of the optical resonator and the laser using same, if any. In a preferred embodiment, the piezo-electrically tuned optical resonator is an optically pumped ring resonator made of a lasant material such as Nd:YAG for tuning the output frequency of the ring laser.

Abstract: A free electron laser (FEL) is described which is used for generating high ower radiation in a region of increasing guiding magnetic field before injection into an undulating low magnetic field. It includes an electron beam propagating along a guiding magnetic field B.sub.0 (approximately 10 kilo gauss) inside a hollow metallic tube used as a wave guide. Around the path of the beam, an undulator in the form of a bifilar helical winding or the like produces a periodic magnetic field B.sub.1 (approximately 0.5 to 1.0 kG). The electron motion accordingly has a substantial transverse component and the motion at the cyclotron and undulator frequencies occurs. Due to the energy exchange between the gyrating component of electron motion and an electromagnetic wave already present in the hollow tube, radiation of a calculable frequency is amplified.

Abstract: Frequency stabilization is disclosed for a laser device, wherein the laser tube is provided with end mirrors which are mounted in extensions at the respective ends of the laser tube. The laser tube extensions have reduced sections which are movable to allow adjustment of the end mirrors in the laser device. The reduced sections are preferably made of metallic material. The means to stabilize frequency provided is the application of heat or current or both to and around a reduced metallic section in the laser tube extension. This may be accomplished by the passing of current through a wire wrapped around the reduced metallic section. The passing of such current causes the reduced metallic section to contract and expand along an axis in line with the laser tube, and as well as a magnetic field is induced upon the gaseous medium within the laser tube. By such means controlled by suitable circuitry, laser frequency stabilization is accomplished.

Abstract: A free electron laser (FEL) is disclosed in which the phase of the output electromagnetic beam is inherently adjustable without the use of any extraneous optical phase shifting materials. This is accomplished by implementing the FEL as a pair of series-connected wiggler cavity sections, and varying the relative phases of the bunched electron flow in the first cavity section relative to the second. In a preferred embodiment a series of electrodes are provided in a transition region between the two cavity sections, and variable voltages are applied to the electrodes to electrostatically control the electron transit time through the transition region, and the electron velocity upon exiting from that region. This translates into a control over phase and frequency.

Abstract: A low-laser-noise semiconductor driver device is provided for use in an optical information processing device which is recordable or erasable and which oscillates a semiconductor laser with a high output when it is recorded or erased. A semiconductor is generally oscillated with a rated maximum output during a recording and erasing operation. Therefore, when high frequency superposition is made in such a high output oscillation state, an oscillation output exceeds the rated output, which badly influences the life of the laser. To obviate this drawback, the high frequency superposition is stopped at the mode of recording or erasing in which the high output oscillation is made by a switching circuit which is controlled by a mode control signal. This reduces the laser noise at the mode of reproducing and also lengthens the life of the semiconductor laser.

Abstract: There is disclosed herein several gas resupply valves for replenishment of lost gas in gas lasers in general and argon ion lasers in particular. The first embodiment uses a valve which controls flow of gas into a metering volume. The metering volume has an aperture therein which is microscopically small and which has a diffusion constant for gas moving through the aperture which is less than the time the valve is held open. The second embodiment uses the same general structure, but separates the soft sealing member of the valve from the solenoid core which moves to open and close the valve. The soft sealing member is attached to the valve body and supported above a valve seat surrounding the opening of the metering volume. The third embodiment uses a thin diaphragm which overlies a flat surface of the valve body in which are formed an input port and an output port. A solenoid applies pressure against the diaphragm to cause it to flatten against the flat surface thereby sealing the valve.

Abstract: The laser has three regions p-n-n+ or n-p-p+ of magnetic element alloyed Group II-VI elements such as Cd, Hg, and Te doped with an element having a high atomic radius such as Sb or In. The magnetic element may be Mn or Fe. Vapor phase epitaxy is used to create a substrate having graded energy band gap characteristic across its thickness. A two-step liquid phase epitaxy process is used to grow an active layer and a passive layer to create the laser heterostructure. The index of refraction of the active region is higher than the indexes of refraction of the substrate and passive regions. The graded energy band gap and high doping of the substrate region results in a very low resistance which minimizes a temperature rise resulting from joule heating at high current densities. The relationship of the indexes of refraction of the layers result in double sided optical confinement to support lasing. In a semimagnetic semiconductor such as HgMnTe, the coefficient dE.sub.

Abstract: A gas laser having a housing terminated vacuum-tight and having magnets that are located in proximity to a capillary, in which excellent action of the magnets is achieved. The housing contains a housing tube and housing parts that are soldered vacuum-tight to the housing tube. At least one part of the magnets are located in the housing tube. The solder that joins the housing tube to the housing parts in a vacuum-tight fashion has a soldering temperature below 500.degree. C. The invention can be advantageously utilized in helium-neon lasers.

Abstract: A device for the preparation of a gas mixture includes a closed circuit. Mixture components of a gas mixture are fed with greatly differing partial pressures ranging from low to highest partial pressures to the closed circuit. The gas mixture is circulated in the closed circuit. At least one of the mixture components with low partial pressure is replenished at increasingly shorter intervals. The gas mixture is completely exchanged when a given minimal length of the intervals is reached. At least one branch parallel to a section of the closed circuit conducts the gas mixture substantially completely free of flow losses.

Abstract: In a monolithic optical ring resonator an optically transparent member is faceted so that the input and output beams of the resonator are coupled through a common facet at widely divergent angles in excess of 45 degrees and preferably 90 degrees. In this manner the resonator is miniaturized. The ring resonator member is contained in an evacuated housing to eliminate time-varying convective thermal detuning effects. The ring resonator is coupled in heat-exchanging relation with heating and temperature sensing film resistors deposited upon a major face of a substrate member.

Abstract: A gas-laser arrangement in which the laser medium is optically pumped. An arc or spark discharge is formed to a helix, particularly by an axial magnetic field. The volume surrounded by the helical arc or spark discharge is optically excited, unimpeded by a physical wall, by radiation from the discharge, especially in the vacuum-uv spectral region, or by resonance lines. Due to the temperature difference between the helical discharge and the gas column along the helix axis, an inversion may be produced in the vicinity of the axis by appropriate choice of gas and the gas composition.

Abstract: The present invention comprises a method and means for stabilizing the frequency difference between the component frequency modes in the beam of a gas laser influenced by Zeeman splitting. Stabilizing the frequency difference makes constant the frequency of the beat signal obtained from heterodyning the component modes. Stabilization is obtained by accurately controlling the difference in frequency between the component frequency modes to provide a selected separation, preferably 250 KHz, with deviation maintained at less than two KHz. The difference in frequencies is controlled independently of the individual frequency or intensity of either of the component frequency modes, or of their relative position within the "Doppler broadened" spectral profile characteristic of the lasing material.

Abstract: An enhancement of approximately 100 of stimulated emission over spontaneous emission of the CVI 182 Angstrom line was obtained in a recombining magnetically confined plasma column. The plasma was formed by focusing a CO.sub.2 laser beam on a carbon disc. A magnetic solenoid produced a strong magnetic field which confined the plasma to the shape of a column. A single thin carbon blade extended parallel to the plasma column and served to make the column axially more uniform and also acted as a heat sink. Axial and transverse measurements of the soft X-ray lasing action were made from locations off-set from the central axis of the plasma column. Multiple carbon blades located at equal intervals around the plasma column were also found to produce acceptable results. According to another embodiment 10 a thin coating of aluminum or magnesium was placed on the carbon disc and blade. The Z of the coating should preferably be at least 5 greater than the Z of the target.

Abstract: An arrangement for coupling a light waveguide, such as a monomode glass fiber to a laser diode and a method of forming the coupling characterized by the laser diode being an integrated part of a semi-conductor chip having a mirrored step projecting out of a seating surface for the monomode glass fiber. The mirrored step defines an end face of the diode from which the laser beam emerges and the seating surface extends parallel to the laser active layer of the diode and at such an interval from the layer that the light entry face of the one end of the waveguide laying flat on the seating surface lies at the same height as the exit point of the beam. The method includes securing the fiber forming the waveguide on the seating surface, and then applying an external magnetic field to the diode to displace and pivot the beam in the laser active layer to adjust the beam relative to the fiber.

Abstract: In laser apparatus, an amplification section of a laser apparatus, including a cavity bounded by first and second opposing surfaces, closely spaced relative to the dimensions of the surfaces, electrodes for generating an electric field within the cavity and magnetic devices for creating a magnetic field in a direction perpendicular to the surfaces, with provision for shaping the electric field so that the electric field is relatively narrow in the dimension parallel to the magnetic field compared to the dimension perpendicular to both the magnetic field vector and the electric field vector established between electrodes within the cavity. The electrodes extend over a distance greater than the spacing between electrodes. An electrical discharge is established with the magnetic field exerting a force on the discharge to move the discharge parallel to the surfaces with the predetermined magnetic field strength causing the discharge to become uniform and stable.

Abstract: An anomalous intensification of the infrared emission from n-InSb having a central wavelength almost equal to the energy gap has been observed, as a result of the cooperation of the magnetoconcentration effect and the photo-excitation, in the temperature range from 80.degree. to 300.degree. K. This suggests that a light amplifier which operates at room temperature can be realized through the process for photons with a wavelength corresponding to the energy gap of the semiconductor material forming the light amplifier concerned. Also the cooperation of the magneto-concentration with the photo-excitation has another useful application as a tunable light source controlled by varying the applied magnetic field through the interband Landau-level transitions at liquid helium temperatures.

Abstract: A method and apparatus for controlling an external cavity of a semiconductor laser to maintain its emission in a single longitudinal mode. The length of the external cavity is varied by an electromagnet acting on ferromagnetic material attached to a copper foil reflector. Total optical power output of the laser is monitored and single longitudinal mode operation is achieved by maximizing the power output. An active technique employs modulation of the reflector position about a mean value. The magnetic manipulation of the reflector may find application in other laser systems, e.g. gas lasers.

Abstract: A quasi-planar monolithic unidirectional ring laser is disclosed including an Nd:YAG crystal shaped so that a ring formed therein has an out-of-plane angle of about 1.degree.. The reflection opposite the output-coupling point on the front face is off the rear face. This arrangement provides for a very low pumping threshold and reduced magnetic field requirements. The disclosed laser can be pumped with a semiconductor laser and yield single mode 1.319 .mu.m and 1.338 .mu.m outputs suitable for fiber optic communications.

Abstract: A gas ion laser employs a direct current electron beam to create a rare gas ion density and a cylindrical magnetron to sputter a partial pressure of metal vapor density and to also create a rare gas ion density. Thermal energy charge transfer selectively pumps the upper metal ion laser transitions on a continuous wave basis.

Abstract: Free electron laser apparatus that provides a magnetic centering force to turn or focus a non-axial electron toward the longitudinal axis as desired. The focusing effect is provided by wiggler magnet pole faces that are approximately parabolically shaped.

Abstract: A solid state cyclotron laser device generate coherent electromagnetic radiation. A semiconductor configuration comprises an emitter region and a collector region separated by a base region and barrier layers on each side of the base. The semiconductor configuration is biased such that electrons enter the base region from the emitter region as hot electrons. A magnetic field applied by an external source to the base region causes the hot electrons to gyrate and quantize into Landau levels. An optical resonance cavity produces standing wave modes which stimulate the electrons to move from higher to lower Landau levels to generate conherent radiation. Electrons with decreased energy are removed at the collector in order to maintain the population inversion. The device is tunable by adjusting the magnetic field.

Abstract: An apparatus for preventing an optical element of a gas laser from being contaminated by vapor. This apparatus comprises pairs of magnets which apply magnetic fields to charged particles moving in the direction of the optical axis of the gas laser so as to deflect them transversely to the optical axis, and a screen for intercepting charged particles moving transversely to the optical axis of the gas laser.

Abstract: A single unitary structure for an ion laser in which the plasma tube with a surrounding electromagnet is integrated with the laser resonator tube. Cooling channels are formed by a pair of annular channels between the resonator tube, electromagnet and plasma tube. A helical, flow path in the annular channels provides uniform cooling around the resonator tube.

Abstract: Soft X-ray lasing action may be obtained by focusing a high power, picosecond laser pulse on a confined plasma column. The plasma column is created by focusing a CO.sub.2 laser pulse on a target such as carbon. A strong cylindrical magnetic field contains the plasma and causes it to assume the shape of a column. While the plasma column is cooling rapidly due to radiation losses, a second high power laser with a duration time of approximately 1 picosecond is focused along the central part of the plasma column. The powerful picosecond laser provides strong selective excitation of the ions for enhancement population inversion and the creation of high gain for X-ray lasing action. According to alternative embodiments, other multi-Z elements such as molybdenum, aluminum and krypton can be used to create a lasing medium in the plasma column.