Abstract: A coupled waveguide injection laser is provided with two waveguiding ridges (36,37 or 60,61) that are configured such that the coupling between them produces a first order supermode for which a signal current modulation produces optical amplitude modulation with substantially no attendant frequency modulation. In a related structure the configuration affords the facility of providing for the zero order supermode optical frequency modulation with substantially no attendant amplitude modulation.

Abstract: A resonant laser cavity system (10) is provided which is divided into three sections (20, 22 and 24). Sections (20 and 24) include a pair of opposing discharge tube members each including an outer discharge tube (28) and an inner discharge tube (26). On opposing ends of resonant laser cavity system (10) there is provided a mirror mounting mechanism (48) which includes a tubular mount housing (50) upon which is mounted a mirror member (58) positionally located through a plurality of metal clamp members (60) inserted within housing grooves (62) and resiliently coupled to the mirror members (58) through a coil spring (64). The inner discharge tube (26) is formed of a Pyrex composition and the outer discharge tube (28) is formed of an acrylic composition.

Abstract: A small closed loop antenna is formed by a flat metal member formed into a U-shape which also serves as the front, back and top surfaces, or parts thereof, of the housing for a portable communications receiver. Connected to the open (bottom) end of the arms is an isolation network providing an optimum antenna ground and a reactance network which applies a capacitive reactance across the antenna and isolation network so that the conductive member forms an antenna that detects the H-field of the electromagnetic wave to be received. The reactance network is tunable to adjust the antenna for reception at particular frequencies.

Abstract: A highly efficient light emitting semiconductor device which is stable at high speeds and has a low threshold current comprising a first semiconductor layer of a first conductive type; a second semiconductor layer of the second conductive type which is different from the first conductive type; an active layer composed of laminated semiconductor layers of the quantum well structure interposed between the first and second semiconductor layers and having a narrower effective energy band gap than the first and second semiconductor layers and a diffraction grading formed in either one of the first or second semiconductor layers.

Abstract: Apparatus for coupling radiation into a single-mode core of an optical fiber laser has a single-mode core disposed within a relatively large, multimode cladding at a location which is displaced from the center of the cross-section of the cladding. The cladding is surrounded by a further layer to prevent radiation from propagating out of the cladding. In addition, the apparatus preferably has slight bends to enhance the coupling of radiation from the cladding into the single-mode core. A further embodiment has a single-mode fiber laser disposed in a relatively large, multimode, slab cladding which, in turn, is surrounded by another cladding to prevent radiation from propagating out of the large cladding.

Abstract: A large scan antenna, particularly for embarked use on board a satellite and for operation in the ultrahigh frequency range, of the type formed of a feed and a main fixed secondary reflector, the antenna being readily foldable into a launching configuration with a minimum of component elements, and comprising at least one guide G each formed of a first and a second parabolic secondary reflectors (12, 13) aligned optically along the axis of the wave guide G between the feed (10) and the main reflector (15), said wave guide G being on the one hand variable in length by moving at least one (13) of said secondary reflectors with respect to the other (12) along the axis (14) of the wave guide G, and on the other hand, rotatable about the axis (11) of the feed (10).

Abstract: A laser generator with a catalyst for the laser gas is provided comprising a cavity which communicates with a housing receiving a catalytic cartridge, which communicates also with a laser gas reserve, and which is subjected to the action of the heat released by the laser effect. The cartridge contains, inside a mechanical filter, granules of zeolite on which a manganese dioxide catalyst has been fixed. The generator, whose output power is stabilized, has a long lifespan.

Abstract: A semiconductor laser array device with a waveguide structure comprising waveguides designed such that the widths thereof gradually increase from the center waveguide to the waveguides positioned at both sides of the array portions.

Abstract: A modulated laser beam emitted from a semiconductor laser is deflected by a rotating light beam deflector to scan a surface, without using an f.theta. lens. The light intensity of the laser beam is set to a first reference level by a reference signal, and to a second reference level by a corrected-width control signal. Each time the frequency-dividing ratio for a reference clock signal from an oscillator is changed, a digital correction signal is produced. The gain of a D/A converter for converting the correction signal is adjusted by the corrected-width control signal which has been converted to an analog signal. The reference signal which has been converted to an analog signal is modulated by the converted correction signal to generate an analog signal which varies in a step-like manner in proportion to a change in the scanning rate.

Abstract: Chromium doped colquiriite, LiCaAlF.sub.6 :Cr.sup.3+, is useful as a tunable laser crystal that has a high intrinsic slope efficiency, comparable to or exceeding that of alexandrite, the current leading performer of vibronic sideband Cr.sup.3+ lasers. The laser output is tunable from at least 720 nm to 840 nm with a measured slop efficiency of about 60% in a Kr laser pumped laser configuration. The intrinsic slope efficiency (in the limit of large output coupling) may approach the quantum defect limited value of 83%. The high slope efficiency implies that excited state absorption (ESA) is negligible. The potential for efficiency and the tuning range of this material satisfy the requirements for a pump laser for a high density storage medium incorporating Nd.sup.3+ or Tm.sup.3+ for use in a multimegajoule single shot fusion research facility.

Abstract: Method and device for correlating the spontaneous emission of photons into laser fields. Atoms of a common lasing medium of multiple laser fields are excited into a coherent superposition of upper levels. When photons are emitted into the laser fields, these emissions are coherent or correlated. The method and correlated emission laser of the invention utilize this correlation to quench the spontaneous emission noise inherent in active laser systems.

Abstract: A semiconductor laser array having a plurality of waveguides at least some of which are directly joined at Y-junctions. The region near the Y-junctions provides a phase boundary condition in which lightwaves propagating in adjacent waveguides are in phase. A combination of strong and weak waveguiding is provided, with strong waveguides that eliminate evanescent coupling from occuring at least in the Y-junction regions, and with weak guides near one or both end facets permitting evanescent coupling. The evanescent coupling between adjacent weak waveguides preserves the in phase relationship that was established in the Y-junction regions, resulting in a diffraction limited single lobe far field output. Alternatively, even without evanescent coupling, the modes can adjust their phases in the weak waveguides, where the propagation constant is less tightly specified by the geometry.

Abstract: A laser driver circuit is disclosed for operating an electrical current driven light emitting device or laser. The laser driver circuit is driven from external equipment by a modulated electrical signal and includes a laser biasing network arranged to provide a threshold current to the laser. The current is sufficient to bias the laser to an operating point just below the laser's turn on threshold. First and second transistors connected to the laser form a differential switching amplifier. The differential switching amplifier is disposed to switch drive current provided by a constant current source to the laser. The drive current is sufficient to drive the laser over the threshold set by the laser biasing network. On the application of the modulated electrical signal to the first transistor of the differential switching amplifier the drive current is switched from one side of the differential switching amplifier to the other effectively turning the laser on and off.

Abstract: A phase-locked ridge waveguide gas laser includes a body that circumferentially bounds an internal space extending along a central plane and containing a gaseous lasing medium. The gaseous medium is excited at radio frequency with attendant light emission from the gaseous medium. Mirrors are so positioned relative to the body as to provide lasing of the light emission. Respective ridges partition the internal space into a plurality of cylindrical laser resonator cavities each sustaining a guided mode of the lasing light emission. Each of the cavities extends longitudinally of the body and is spaced from an adjacent cavity by a predetermined distance in a width direction of the internal space. The ridges are substantially cusp-shaped and extend into the internal space along a height dimension in respective aligned pairs.

Abstract: A phase-locked ridge waveguide gas laser includes a body having two major and two minor limiting surfaces together circumferentially bounding an internal space within the body, which contains a gaseous lasing medium. The gaseous medium is excited at radio frequency with attendant light emission from the gaseous medium. Mirrors are so positioned relative to the body as to provide lasing of the light emission. Respective ridges partition the internal space into at least three laser resonator cavities each sustaining a guided mode of the lasing light emission. The ridges extend in an alternative fashion from one and the other of the major surfaces of the body into the internal space and terminate short of the respectively other of the major surfaces to provide respective gaps. Each of these gaps connects two adjacent ones of the laser resonator cavities for phase-locking the guided modes in such cavities.

Abstract: A distributed-feedback type semiconductor laser device having an active layer arranged between a pair of clad layers is provided with a stripe-shaped distributed-feedback mechanism, for example, having the configuration of a diffraction grating, and dummy regions of the same configuration as the distributed feedback mechanism arranged at opposite sides of the latter and being spaced from the distributor-feedback mechanism by relatively narrow plane regions, with the result that the distributed-feedback mechanism can be formed as a narrow stripe with good reproducibility so that it is possible to provide the semiconductor laser device with a long useful life and with the capability of operating in single longitudinal and transverse modes.

Abstract: A method for creating population inversions for use in stimulated emission devices which beam combine, beam clean-up, or frequency up-convert electromagnetic radiation. The invention comprises near resonantly enhanced multiphoton pumping of a multilevel quantum medium with pump beams of appropriate intensities and frequencies detuned from the transition frequencies of the medium. The intensities are orders of magnitude lower than those required for non-resonantly enhanced multiphoton pumping. The detuning is smaller for the maximum multiphoton resonance than for the single photon resonances. Appropriate medium decay constants are required for creating a population inversion between energy levels of the quantum medium. The population inversion exists between energy levels of the medium whose energy difference may exceed the energy of any single pump photon energy.

Abstract: A phase-locked staggered ridge array waveguide gas laser includes a body that circumferentially bounds an internal space extending along a central plane and containing a gaseous lasing medium. The gaseous medium is excited at radio frequency with attendant light emission from the gaseous medium. Mirrors are so positioned relative to the body as to provide lasing of the light emission. Two arrays of ridges extending into the internal space along a height dimension partition the internal space into two pluralities of laser resonator cavities each sustaining a guided mode of the lasing light emission. Each of the cavities extends longitudinally of the body and is spaced from an adjacent cavity in a width direction of the internal space.

Abstract: A high power gas laser and, in particular, a high power continuous wave gas laser. The discharge chamber of the laser has a plurality of first electrodes. The electrodes of opposite polarity take the form of a coil. The first electrodes take the form of a plurality of metal pins protruding from the wall of the discharge chamber. Gas is introduced into the discharge chamber tangentially which circulates with a vortex type motion from the upstream instroduction point to the exit chamber where it is split and exits by a conical flow divider. A portion of the gas travels from the flow divider upstream due to the back pressure of the flow divider resulting in improved vortex flow in the discharge chamber and exits at the upstream end. The discharge chamber of the laser may assume a conical configuration.

Abstract: A distributed feedback semiconductor laser device with a resonator comprising a multi-layered optical waveguide that contains an optical guiding area with a periodic corrugation, the optical guiding area being composed of at least two regions, a first region I and a second region II, wherein both the periodicity of the corrugation and the depth of each concave portion of the corrugation of the first region I of the optical guiding area are the same as those of the second region II of the optical guiding area, and moreover the thickness of the first region I of the optical guiding area is the same as that of the second region II of the optical guiding area, so that the effective refractive index of the first region I in the resonator direction becomes the same as that of the second region II in the resonator direction and the Bragg wavelength is maintained at a fixed level in the the resonator direction; and there is a difference in their refractive index at the interface between the first and second regions o