Abstract: A solid-state laser having a smoothly moving lasing material. A closely toleranced, fluid-bearing assembly extends around the slab of moving lasing material for both supporting and cooling the slab of material with a film of a thermally conductive fluid, such as helium. The lasing means, which causes a portion of the lasing material to heat, is immediately adjacent the fluid-bearing assembly, and the heated lasing material is moved into the fluid-bearing assembly for cooling as soon as possible after it has been heated by the lasing operation. The slab of lasing material can be in the form of a rectangular block or a ring with a rectangular cross section. In the first case, the slab of lasing material is moved through the fluid-bearing assembly in a back-and-forth motion by a transport mechanism. In the second case, the ring is cooled by driving it through the fluid-bearing assembly in a single direction.

Abstract: The aerodynamic window of the present invention provides a barrier between two different environments of a high energy laser device. The first environment is a transverse gas flow across the laser beam and the third environment is an axial flow beam path. The window having a second environment therein changes both the gas temperature and the gas pressure along the laser beam to minimize optical path differences between the first and third environments. The second environment has a thermal transition section and an injection section. In the thermal transition section before the injection section, a gas manifold provides a varying gas flow field. The thermal transition section changes the gas temperature while maintaining its pressure and velocity constant. A transverse flow is exhausted in a location opposite to the gas manifold. The axial flow enters into the injection section. Gas ejectors in the injection section mix the axial flowing gas and increase the gas pressure and velocity.

Abstract: A resonant quantum well laser incorporates semiconductor barriers on one or both sides of the quantum well to increase the charge density within the quantum well. The composition of the injection layers can be tailored in a manner that the energies of the charge carriers in the injection layers are about that of a resonant energy level for that type of charge carrier in the quantum well. The barrier layers on one or both sides of the quantum well enhance the probability of the charge carrier being in the well for a longer time and travelling a longer distance, increasing the chance of scattering. The charge carriers, electrons or holes, can move from their respective injection layers into nearly identical energy levels within the quantum well, by tunneling through the thin barrier layers. The number of carriers which are available to transfer into the lasting energy level is increased, thereby increasing the efficiency of the laser and lowering its threshold current.

Abstract: A laser system having a gaseous Raman cell incorporate methane (CH.sub.4) as the Raman scattering medium. The cell includes gaseous hydrogen to prevent deposition of carbonaceous material from decomposed methane on the windows of the Raman cell.

Abstract: A linear array of multimode laser diodes in a single wafer having a ratio of approximately one emitting stripe width to each non-emitting stripe isolation region width exhibits transverse lasing in a direction perpendicular to the normal laser output at input currents above a pre-determined transverse lasing threshold. Above the transverse lasing threshold, normal lasing is rapidly quenched.

Abstract: The laser device has a plurality of parallel index-waveguides. The intermediate regions of the waveguides are at an angle of inclination from a line perpendicular to each of both facets of the laser device. The ends of the waveguides are oriented orthogonally to the facets of the laser device.

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: The laser device has an Al.sub.x Ga.sub.1-x As (x.gtoreq.0.3) quantum well active region having a thickness of 200 angstroms or less. Al.sub.y Ga.sub.1-y As (y>x) carrier supplying layers sandwich the quantum well active region therebetween. An Al.sub.z Ga.sub.1-z As (z>y) cladding layer is disposed on each of the carrier supplying layers. Finally an Al.sub.w Ga.sub.1-w As (w>z) barrier layer is disposed between each of the carrier supplying layers and each of the cladding layers.

Abstract: An optically stable resonator producing a laser beam which by the use of a converging and of a diverging optical element is subdivided into an amplifier part with large beam diameter and small energy density and into a mode filter part with small beam cross section and correspondingly small Fresnel number all with a short structural length of the resonator. The advantage of the present invention resides in the high beam quality of the produced beam which contains predominantly only the fundamental mode, and in the small thermal load of the participating elements, especially of the decoupling window. The subdivision of the stable resonator according to this invention into an amplifier part and into a load filter part opens up to this resonator type power output ranges which were precluded heretofore by reason of a maximum permissive thermal load of the decoupling window.

Abstract: A device for driving a laser (2) includes a quiescent-current means (3) which supplies, under control of a negative feedback current (I.sub.D) from a photodetector (9), a quiescent current (I.sub.B) to the laser in order to stabilize the laser light output at a level corresponding to a logic one value of a digital input signal (D). A modulation device (10), which comprises a converter, is responsive to the digital input signal to supply a first drive current (i.sub.M1) to modulate the laser. The modulation device supplies a second drive current (i.sub.M2), complementary to the first drive current, to a compensation device (20) which, for a logic zero signal, applies a compensation current (I.sub.C) to the quiescent current means thereby to reduce the light level.

Abstract: A semiconductor laser device arranged so that at least one of cladding layers is formed of a thin AlGaInP layer having a larger energy band gap as compared with an active layer adjacent to the active layer and an AlGaAs layer having a high thermal conductivity as compared with that of the AlGaInP layer and the larger energy band gap as compared with the active layer, which is located between the AlGaInP layer and a heat sink, whereby a heat generated in the active layer is effectively radiated to the heat sink, thus the semiconductor laser being made capable of continuously emitting a laser light of a short wavelength at a room temperature.

Abstract: A laser device is disclosed having mirror heating to enhance performance of the device by minimizing induced light absorption to thereby improve mirror quality. The mirrors of a laser device are commonly made of a substrate having a coating thereon formed by alternating layers of high and low refractive index materials, normally classified as refractory oxide materials, which materials are susceptible to formation therein of color centers, such as formation of F-centers when exposed to ultraviolet light, which color centers reduce mirror quality due to induced light absorption losses. By heating the mirror, the F-centers are substantially eliminated to thereby improve mirror quality and enhance the longevity of the laser device.

Abstract: In a gas laser device according to this invention, a gas inlet having an electrode protrudes within each of expanded portions protruding on the side, where the gas inlet is disposed, of the principal portion of the discharge tube. Gas medium ejected from the gas inlet in the principal portion of a discharge tube collides with the inner surface of the principal portion of a discharge tube, while forming a flame extending along the ejected gas medium from the electrode and is divided into two partial flows. One of them flows along the wall of the expanded portion; collides with the gas inlet; and is divided further into two partial flows. Therefore it does not collide with the gas medium within the gas inlet. Consequently the gas medium and the flame fluctuate hardly and are stabilized. In this way it is possible to stabilize the laser output.

Abstract: A laser gas used in a rare gas halide excimer laser is efficiently refined with little loss of the essential rare gas such as Kr, Ar or Xe by contact of the laser gas with a solid alkaline compound, e.g. Ca(OH).sub.2, for conversion of acidic impurities and also the halogen source gas such as F.sub.2 or HCl into solid metal halides and contact of the remaining gas with zeolite which is adsorbent of the remaining impurities. When the halogen source gas comprises a highly oxidizing fluorine matter the laser gas is first brought into contact with a reactive metal, e.g. Si or Fe, to convert the oxidizing fluorine matter into metal fluorides to thereby prevent formation of O.sub.2, which is obstructive to the laser operation, by reaction of the oxidizing matter with the alkaline compound.

Abstract: A semiconductor laser includes a mesa-striped laser structure. A substrate has layered on it an active layer with a refractive index higher than that of, and with an energy gap smaller than that of the substrate. A first electrode is formed under the substrate. A cladding layer of a conductivity type different than that of the substrate overlays the active layer. A multilayered burying crystal includes, at the sides of the mesa-striped laser structure, successively first, second and third burying layers. The first and third burying layers are of the same conductivity type as the substrate. The second burying layer is of a conductivity type different from that of the substrate. A cap layer of a conductivity type different than the substrate covers the upper face of the mesa-striped structure and an upper face of the third burying layer. A second electrode is formed on the cap layer. Injected current flowing into a thyristor composed of the cap layer and the three burying layers can be suppressed.

Abstract: A comb-shaped polarizing device for use in a laser is compact, inexpensive and easily adjusted. The device includes an annular member having a number of comb-shaped teeth projecting opposite similarly shaped teeth from a rectangular aperture. The comb-shaped teeth are arranged in a plane transversing a laser beam which is under oscillation. Cooling water passages are formed in the annular member. In one embodiment the annular member is provided at its periphery with gear teeth which mate with a motor for selection of the direction of polarization of the laser beam.

Abstract: A relatively low-power but high-quality laser oscillator is coupled to a high-power laser amplifier. The amplifier includes a rectangular slab of laser active material, and a phase-conjugate end mirror.

Abstract: A monolithic external-coupled-diode laser structure uses high reflectivity facet coatings to reduce the operating current and to improve suppression of unwanted longitudinal modes.

Abstract: An optical resonator for a laser oscillating apparatus has an arrangement of folding mirrors facing one another across the lasing gas medium that radiates the laser beam. The arrangement includes a pair of reflecting surfaces that are approximately orthogonal to one another and effectively face the lasing gas medium as a whole. Also, the laser beam that is incident from the lasing gas medium is caused to be reflected successively from both reflecting surfaces to be emitted in the direction of the lasing gas medium.

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.