Abstract: A superluminescent diode has an active layer confined in a channel cut into current blocking layers on a semiconductor substrate. This structure gives a small output beam diameter and high coupling efficiency, even when coupled into single-mode fiber. At the end of the channel distant from the output facet, the active layer makes slanting contact with a rough diffusing surface formed by the current blocking layers and substrate. This easily-manufactured diffusing surface reduces optical gain within the active layer, thereby preventing lasing without requiring an antireflection coating.

Abstract: An apparatus for generating a coherent combined laser beam including an array of laser elements for generating a Fresnel diffraction pattern in a plane at a distance D from the laser array, the Fresnel diffraction pattern having a non-uniform phase distribution, D being at least as large as the distance at which the beams generated by the laser array begin to substantially overlap; and an array of phase corrector elements located in the plane for reducing the degree of non-uniformity in the phase distribution; and a partially reflecting mirror for forming a resonant cavity for the laser array.

Abstract: In an optical semiconductor device which comprises a mount (52a) for holding an optical semiconductor element (40) and a lens holder (54a) which holds a lens (50) for converting a beam shape of a light emitted from the optical semiconductor element (40) and is fixed to the mount (52a) and a production method thereof wherein at least one of locations for shrinkage by laser irradiation (58a) are provided at least on one of the mount (52a) and the lens holder (54a), and the relative positions of the optical semiconductor element (40) and the lens (50) are adjustable in any desired direction by a laser irradiation on the location for shrinkage by laser irradiation (58a).

Abstract: Full duplex lightwave communications is achieved in a diplex transceiver realized in a semiconductor photonic integrated circuit having an inline interconnecting waveguide integral with the transmitting and receiving portions of the transceiver. Semiconductor lasers and detectors operating in different wavelength regimes permit diplex or wavelength-division-multiplexed operation. In the transceiver, lightwave signals from the laser propagate through the laser without interfering with the laser operation or the lightwave signals being generated.

Abstract: An improved nitrogen laser includes two oppositely disposed discharge electrodes contained within a resonant chamber that is supplied with a mixture of nitrogen gas and a substantially small amount of electronegative gas. The mixture used within the chamber makes it possible to operate the nitrogen laser at a high voltage output and a higher frequency rate.

Abstract: A high power injection-locked laser system (10) is disclosed which includes master and slave lasers (12, 14) both of which are solid state lasers having continuous wave outputs. The slave laser has an output power at least ten times greater than the master laser. In the preferred embodiment, the slave laser is at least one-hundred times as powerful as the master laser. In accordance with the subject invention, a servo-loop control system is used to maintain the injection locked condition. A discriminant signal is generated that is indicative of drift in the slave laser cavity. The discriminant signal is used adjust the length of the slave laser cavity to maintain the locked condition.

Abstract: An apparatus for coherent beam combining of lasers and for lateral mode control is disclosed, comprising a miniature Talbot cavity having at least a first and second surface. The first surface is to receive light from said lasers, and the second surface contains a reflecting mirror. In one embodiment, the mirror spaced apart from said first surface by a distance Z=nd.sup.2 /.lambda. where n is a nonnegative integer, .lambda. is the laser wavelength, and d is the laser aperture spacing. In this embodiment, the mirror is divided into reflecting and non-reflecting portions, the reflecting portions patterned to reflect only that portion of the light from said lasers having a half-period shift corresponding to a fundamental lateral mode. In another embodiment, the mirror is spaced apart from the first surface by a distance Z, such that nd.sup.2 /.lambda.<Z<(n+1)d.sup.2 /.lambda., where n is a nonnegative integer, .lambda. is the laser wavelength, and d is the laser aperture spacing.

Abstract: A laser light beam is processed in a first optical path to produce light indications in a plurality of free spectral paths. These light indications are introduced through slits to produce signals at spaced positions at the opposite peripheries of a linear detector array. The distances between correlated pairs of energized detectors at the opposite peripheries of the array indicate the relative value of the laser wavelength in the free spectral ranges. The laser light beam is also processed in a second optical path, simultaneously with the processing of the laser light beam in the first optical path, to produce light in a single path. The second optical path is dependent upon the wavelength of the laser light beam. The light produced in the second optical path may be introduced through another slit to energize centrally disposed detectors in the array. The particular detectors energized are dependent upon the wavelength of the laser light.

Abstract: Disclosed is an optical pumping-type solid-state laser apparatus in which a semiconductor laser device is used as a light source for optical pumping. The solid-state laser apparatus includes first and second photodetectors. The former detects the amount of light emitted from the semiconductor laser device, and the latter detects the amount of laser light transmitted through a filter plate which has the same light-absorbance characteristics as that of the solid-state laser. In accordance with the detected results, a driving circuit drives the semiconductor laser device to obtain a laser beam with an appropriate output level and a temperature regulator regulates the temperature of the semiconductor laser device so that the wavelength of the laser light to be emitted therefrom is accurately adjusted to be the same as that of the light to be efficiently absorbed by the solid-state laser. The laser beam with the accurately adjusted wavelength is used for optically pumping the solid-state laser.

Abstract: A large number of semiconductor laser sources coupled with tapered fibers provide a high energy density output for the purpose of longitudinal pumping of a solid state gain medium in an unstable resonator. Each semiconductor laser source generates a beam of radiation at the pump wavelength having characteristic lateral and transverse widths. A plurality of light transmitting fibers, each fiber having an input end and an output end, is coupled with the semiconductor laser sources for delivering the light from a remote location to pump the gain medium. The input end of each fiber has a cross-section substantially matching the transverse and lateral widths of the beams generated by the corresponding semiconductor laser source, and is coupled to receive the beam of radiation generated by a corresponding semiconductor laser source. The output ends of the light transmitting fibers are bundled to deliver the beams coupled into the fibers as a composite light source having a high energy density.

Abstract: This semiconductor laser driving apparatus for driving a semiconductor laser and to be used for an optical information recording and reproducing apparatus doing at least one of recording and reproducing information in an information recording medium by using a light from the semiconductor laser comprises an emitted light amount detecting device for detecting the emitted light amount of the semiconductor laser, an output controlling device for controlling the output of the semiconductor laser on the basis of the detected output of the emitted light amount detecting device so as to be kept constant, a driving device for feeding said semiconductor laser with an operating direct current, a high frequency superimposing device for superimposing a high frequency current on the operating direct current from the driving means, a measuring device for measuring the variation of the emitted light amount of the semiconductor laser with the variation of the operating current of the semiconductor laser in the absence of the

Abstract: A semiconductor laser drive device modulates optical output of a semiconductor laser in accordance with an externally provided modulation signal comprises a compensation circuit for calculating a compensation coefficient and for generating a compensation modulation signal, a threshold value current generation circuit for generating and a threshold value current to the compensation modulation signal and sending the added current as a drive current, and a current drive circuit for driving the semiconductor laser based on the drive current sent from the threshold value current generation circuit. In accordance with the semiconductor laser, the optical output error caused by the temperature change of the semiconductor laser is compensated.

Abstract: A tunable, singley-resonant optical parametric oscillator provides femtosecond light pulses in the infrared wavelength band. The oscillator includes an internally mounted thin crystal of KTiOPO.sub.4 which is synchronously pumped by femtosecond pulses from a colliding-pulse passively mode-locked dye laser. Rotation of the crystal varies the wavelength of the oscillator. Prisms within the oscillator cavity control group velocity dispersion to limit pulse width, and the oscillator as stabilized by a feedback network which varies the length of the cavity in response to spectral changes.

Abstract: A method and apparatus is disclosed that provides a laser output beam having a broad bandwidth and an intensity smooth over time. The bandwidth of the laser output can be varied easily by varying the intensity of a broadband source. The present invention includes an optical modulation apparatus comprising a narrowband laser that outputs a horizontally polarized beam (a "signal beam") and a broadband laser that outputs a vertically polarized beam (a "pump beam") whose intensity varies rapidly. The two beam are coupled into a birefringent laser material so that the respective polarizations coincide with the principal axes of the material. As the two beams travel through the material, the polarization preserving properties of the birefringent material maintain the respective polarizations of the two beam; however there is coupling between the two beams as a result of cross phase modulations, which induces a bandwidth change of the signal beam.

Abstract: A laser diode in the form of a chip with a heat sink connected to an electronic control circuit, is positioned in front of a light conductor for emitting light into the light conductor. The light conductor (103), such as a fiber (101) of a glass fiber cable (102), passes through a hole in the wall of a housing (100) for the electronic control circuit. The light conductor end is precisely adjusted in the Z-direction of an X-Y-Z-coordinate system, and rigidly held in the adjusted position in a bore or slot (17a) of a mounting block (17). The laser diode (10) with its chip (11) and its heat sink (12) are held in a roughly adjusted position in a milled recess (17c) of the mounting block (17) relative to the tip of the light conductor by a compression leaf spring (14) which permits an adjustment of the laser diode with its chip and heat sink in the X- and Y-direction for a precise adjustment. A displacement gripper tongue mechanism is then used for a precise position adjustment in the X- and Y-direction.

Abstract: A laser and method for producing a laser emission at a wavelength of substantially 2.8 microns is disclosed. In a preferred embodiment of the invention, the laser comprises laser diode means for emitting a pump beam at a preselected wavelength; a crystal; and a laser cavity defined by first and second reflective elements at opposing ends of the crystal to form a reflective path therebetween; the crystal having a preselected host material doped with a predetermined percent concentration of erbium activator ions sufficient to produce a laser emission at substantially 2.8 microns when the crystal is pumped by the laser diode means, a portion of the laser emission at substantially 2.8 microns being outputted from one of the first and second reflective elements at a slope efficiency of at least 5 percent, but preferably 10 percent, when the crystal is pumped by the pump beam.

Abstract: The output polarization of a twin guide semiconductor laser is switched either by controlling the operating current of both guides or by injecting an optical signal. Twin-stripe and twin-ridge lasers of InGaAsP are described. True polarization bistability is reported for a range of devices: the effect is temperature insensitive.

Abstract: The disclosure concerns an integrated circuit which forms an electronic power device. This integrated circuit has, supported by a substrate, at least one array of lasers and at least one flat bar of reflectors. The reflectors send back the laser beams, emitted parallel to the substrate, perpendicularly to the substrate. The cleaved faces of the lasers are obtained by the sub-etching of the arrays, then through breaking by ultrasound.

Abstract: A system for improved drive and matching between an RF power source and a plasma tube in a laser system. The system uses standard 50 or 75 ohm quarter wave transmission lines as the sole interconnect and matching elements between discharge electrodes and drive transistors. The drive transistos may be operated in deep saturation or as switches providing near square wave output to approach the 100 percent theoretical electrical efficiency of switching power supplies. The system features better initial breakdown, bettwer discharge uniformity and power stability under narrow drive pulse conditions, lower matching electrical losses, and extreme simplicity and low cost.

Abstract: An angled-stripe superluminescent laser diode (SLD) light source emits both coherent and incoherent radiation simultaneously, but the two beams are separated spatially. A method and apparatus for stabilizing the emission wavelength of a broadbent light source for a fiber-optic rotation-sensing gyro uses the coherent radiation from an angled-stripe SLD as the optical source in a large-optical-pathlength-difference interferometer to generate an error signal which is fed back to the current source of the SLD to stabilize the wavelength of the incoherent part of the SLD light output.