Abstract: The invention provides a laser medium having improved photodynamical properties. The medium includes the condensed phase, namely solid or liquid phase, of a mixture of one or more rare gases and a halogen donor. The gases are first combined and then condensed to form the laser medium. A solid state rare gas crystal laser is also provided.

Abstract: A laser diode array in which a conductive layer is provided over a nonconductive or insulating layer, grooves being formed in the conductive layer, and laser diodes being disposed in the grooves. In one embodiment, the layers are separate; in another embodiment, the conductive and nonconductive layers are provided in the same monolithic substrate, which may be undoped semiconductor material such as silicon, with a highly doped upper portion in which the grooves are formed. In another embodiment of the array, the diodes are mounted in the grooves such that at least a portion of their light is emitted towards a bottom of the array.

Abstract: The life expectancy of a ring laser gyroscope has been greatly extended by the addition of a gas capsule (24) which holds a large quantity of lasing gas at high pressure in a very small volume. The gas is selectively admitted to the triangular tunnel (12) through a membrane (32). In a preferred embodiment, permeability of the membrane (32) varies with temperature and a platinum heating element (36) is deposited on the membrane (32) for the purpose of regulating the diffusion of the lasing gas through the membrane. A pressure sensor (44) is connected to the triangular tunnel (12) for sensing a decrease in lasing gas pressure therein. A servo control (46) utilizes information supplied by the pressure sensor (44) to regulate the energization of the heating element (36). In one arrangement, a silicon substrate (50) is common to both the pressure sensor (46) and the gas capsule (24).

Abstract: Light input means inputs exciting pulse light beams to a parametric oscillator simultaneously in a plurality of directions. The parametric oscillator including a parametric element such as a urea crystal produces parametric pulse beams having different wavelengths. The parametric pulse beams are corrected into coaxial beams by a correcting optical means which includes an optical fiber, and then group dispersion of the coaxial beams are compensated for by a group dispersion compensating means which includes opposed diffraction gratings.

Abstract: A second-order predistortion circuit for linearizing a nonlinear device having a transfer function of the form F=C.sub.1 I.sub.1 -C.sub.2 (I.sub.1).sup.2, where I.sub.1 is a current applied to an input of the nonlinear device, and C.sub.1 and C.sub.2 are constants. The nonlinear device is typically a laser diode. The predistortion circuit includes a field effect transistor biased for square law operation. An input voltage is applied between the gate and source electrodes of the field effect transistor. An amplifier is connected between the drain electrode of the field effect transistor and the input of the nonlinear device. The gain of the amplifier is selected to minimize second-order distortion in the output of the nonlinear device as a function of the input voltage to the field effect transistor.

Abstract: A semiconductor laser apparatus comprises a DC power supply coupled with an RF source which generates a low-amplitude RF current which is injected into a diode laser source. An optical beam shaping system processes the laser beam and directs it to a nonlinear resonator having a plurality of longitudinal resonator frequencies with a fundamental spatial mode. The nonlinear resonator uses a phase-matched, second harmonic generation (SHG) process to generate a second laser beam by frequency doubling the central carrier frequency of the diode laser source, and further reflects a portion of the incident laser beam to an electronic resonance locking system. The electronic resonance locking system has a photodetector to receive the reflected portion of the incident beam from the resonator and generates an RF signal arising from the difference in phase shifts or amplitude losses experienced by the RF sidebands.

Abstract: Part of a laser beam, which is generated by a laser tube and reflected by a reflection surface of a high-reflectance mirror to travel while diverging at the predetermined angle, is divided by a dividing mirror. The spectral band width of the divided laser beam is narrowed by an etalon and a diffraction grating. The laser beam with the narrowed spectral band width is reflected by a high-reflectance return mirror, returned to the laser tube, and amplified in the laser tube. The laser beam with the narrowed spectral band width is amplified in substantially the same space within the laser tube where the laser beam was generated.

Abstract: A compact RF excited annular laser system has a stable resonator with a high quality output beam. The stable resonator has internal axiconical and annular mirrors to conform with the annular lasing medium, and to convert the annular beam into a compact cylindrical beam. Mode control is achieved by a combination of diffractive effects in both the annular beam and the compact beam.

Abstract: A process for reducing energy losses in crystals is disclosed which comprises:a. heating a crystal to a temperature sufficiently high as to cause dissolution of microscopic inclusions into the crystal, thereby converting said inclusions into point-defects, andb. maintaining said crystal at a given temperature for a period of time sufficient to cause said point-defects to diffuse out of said crystal.Also disclosed are crystals treated by the process, and lasers utilizing the crystals as a source of light.

Abstract: A gas replenishment system for a gas laser utilizes a gas metering device between a gas reservoir and the gas laser tube which operates at a pressure below the gas reservoir pressure. The metering device incorporates a body of gas entrapping material. The tube pressure is detected and when low an electrically controlled valve is energized for a predetermined time which allows gas to flow from the reservoir, into the gas entrapping material and from there to the tube. If the tube pressure is not restored to its proper level, the system recycles for another equivalent period of time.

Abstract: In order to so improve a high-frequency-excited, diffusion-cooled waveguide laser comprising a folded, unstable laser resonator with a first resonator axis branch and a second resonator axis branch, a folded, optical waveguide with a first waveguide branch and a second waveguide branch penetrated by the first and the second resonator axis branch, respectively, in their longitudinal direction, and each having two spaced, optical waveguide surfaces, and at least one reflection element with a reflection surface coupling the waveguide branches with one another, that as low reflection losses as possible occur with the folding and that the laser is as compact as possible, it is proposed that the two waveguide branches be coupled with one another at a first end by a single, first reflection surface, each with single beam reflection thereat, in that the two resonator axis branches intersect at their point of impact on the first reflection surface and that the two waveguide branches be curved in the direction towards

Abstract: A high electrical power is input in a gas-swept electrical discharge for gas laser by controlling with a high electrical efficiency and without dissipative resistance. A discharge chamber is swept through with a gas at a high velocity wherein transverse to the flow direction, the gas discharge burns as a steady-field discharge between an anode and several cathodes opposite the anode. These are disposed in tandem in the flow direction. Power is supplied to each individual cathode by means of a fast, independently controlled switched-mode power supply unit constant current characteristics wherein the current is supplied to the switched-mode power supply unit by series-connected partial voltage sources of the cathodes. A pre-ionization device is provided on the flow bounding surface of the discharge chamber.

Abstract: The invention comprises a laser light source for a raster laser display. The laser light source comprises a laser cavity, a lasing medium within the cavity, a lasing light source and a series of mirrors within the cavity arranged to reflect the beam of laser light repeatedly through the lasing medium. An acoustic modulator is included having an acoustic medium within the path of the beam within the cavity. Video information on each pixel of the display is converted to an RF signal and fed to a piezoelectric crystal which is coupled to the acoustic medium. The acoustic medium is arranged within the laser cavity with respect to the incident laser beam such that, in response to the acoustic information, the laser beam is either directed towards the screen, or when not needed for the display is directed towards one of the mirrors such that the beam can continue to propagate through the lasing medium.

Abstract: Ultra short (pico second and shorter) laser pulses having components of different frequency which are overlapped coherently in space and with a predetermined constant relationship in time, are generated and may be used in applications where plural spectrally separate, time-synchronized pulses are needed as in wave-length resolved spectroscopy and spectral pump probe measurements for characterization of materials. A Chirped Pulse Amplifier (CPA), such as a regenerative amplifier, which provides amplified, high intensity pulses at the output thereof which have the same spatial intensity profile, is used to process a series of chirped pulses, each with a different central frequency (the desired frequencies contained in the output pulses). Each series of chirped pulses is obtained from a single chirped pulse by spectral windowing with a mask in a dispersive expansion stage ahead of the laser amplifier. The laser amplifier amplifies the pulses and provides output pulses with like spatial and temporal profiles.

Abstract: A birefringent quartz plate is inserted in the laser cavity to generate two orthogonal polarized beams with different frequencies, and with the amount of frequency difference depending upon the angle of orientation of the crystalline axis of the quartz plate with respect to the longitudinal axis of the laser beam in the cavity. Frequency differences between the generated dual frequency beams can be varied from tens of MHz to more than 1000 MHz, with tuning or variation being effected by a mechanism for rotating the quartz plate. This apparatus provides a dual-frequency laser for interferometry, laser Doppler velocimeters and other applications.

Abstract: The field of the invention is that of power lasers pumped by coherent optical sources, such as laser diodes. The aim of the invention is to provide a structure of illumination of a laser rod enabling both efficient removal of the calories released by the coherent optical pumping sources and high homogeneity of the rod pumping operations. The structure is characterized in that the optical sources of at least one set of optical sources are arranged on one and the same delocalized support and in that said structure comprises reflecting means for the transmission, towards the rod, of the illumination beam from said set of delocalized optical sources.

Abstract: In response to fundamental laser light, a LiNbO.sub.3 crystal emits second harmonic laser light. A phase matching angle of 90 degrees is obtained at room temperature by using a LiNbO.sub.3 crystal doped with MgO at a proper concentration. In the case where fundamental laser light of 1064 nm is applied from a Nd-YAG laser, the concentration of MgO should be about 1.0 mol % or about 7.5 mol %.

Abstract: Apparatus and method for scaling solid-state devices to higher power using multiple sources each of which are separately collimated, followed by focusing of the pump radiation into gain medium colinear to laser mode using a moderated focus. A modularized system is also described.

Abstract: Disclosed is a power laser in which several laser diodes emit pump beams towards amplifier media. The beams coming from these amplifier media are combined by an optical system to give a common beam transmitted to an output mirror. The mirror and a reflecting face of each amplifier forms an optical cavity.

Abstract: An axial flow gas transport laser comprising an excitation tube through which gas flows along an axis of the tube, an inlet arrangement to feed gas towards the excitation tube and an outlet arrangement to discharge gas from the excitation tube. At least one of the inlet and outlet arrangements comprises a circumferential opening arrangements evenly distributed along the periphery of the excitation tube, substantially in a cross-section plane of the tube. A gas flow channel arrangement to the opening arrangement is directed at least substantially in the direction of the excitation tube axis and into the excitation tube at the opening arrangement for preventing wide-areal turbulances of the gas flowing in the excitation tube.