Abstract: A laser diode package includes a heat sink, a laser diode, and an electrically nonconductive (i.e. insulative) substrate. The laser diode has an emitting surface and a reflective surface opposing the emitting surface. The laser diode further has first and second side surfaces between the emitting and reflective surfaces. The heat sink has an upper surface and a lower surface. The first side surface of the laser diode is attached to the heat sink adjacent to the upper surface. The substrate is attached to the lower surface of the heat sink. The heat sink is made of heat conducting metal such as copper and the substrate is preferably made from gallium arsenide. The substrate is soldered to the heat sink as is the laser diode bar. Due to the presence of the substrate at the lower end of the heat sink, each individual laser diode package has its own electrical isolation. Several packages can be easily attached together to form a laser diode array.

Abstract: A laser beam generation apparatus includes a solid state laser medium having first and second optically polished planes provided opposed with each other to allow a laser beam to be pumped to pass out of one of the first and second optically polished planes. At least one third optical polished plane which is different from the first and second optically polished planes is also provided. A pumping beam source emits a pumping light beam to pump the laser medium and impinges the pumping light source to be incident on the at least one third optically polished plane. Further, the pumping laser beam is provided at an incident angle substantially equal to the Brewster angle.

Abstract: In a semiconductor-laser device: an n-type cladding layer, an optical-waveguide layer, an Inx3Ga1−x3As1−y3Py3 compressive-strain quantum-well active layer (0<x3≦0.4, 0≦y3≦0.1), an optical-waveguide layer, a p-Inx6Ga1−x6P etching-stop layer (0≦x6≦1), a p-Inx1Ga1−x1As1−y1Py1 etching-stop layer (0≦x1≦0.4, 0≦y1≦0.5), a p-InxGa1−xP layer (x=0.49±0.01), and an n-InxGa1−xP current-confinement layer are formed on an n-GaAs substrate. A stripe groove is formed down to the depth of the upper surface of the p-Inx6Ga1−x6P etching-stop layer. A p-Inx4Ga1−x4As1−y4Py4 cladding layer (x4=0.49y4±0.01, x−0.04≦x4≦x−0.01) is formed over the current-confinement layer and the stripe groove. A p-type contact layer is formed on the p-Inx4Ga1−x4As1−y4Py4 cladding layer. The absolute value of the product of the strain and the thickness of the active layer does not exceed 0.

Abstract: A solid-state laser rod pumping module has a stack-type semiconductor laser including a plurality of bar-shaped components that are stacked in a direction parallel to the axis of a solid-state laser rod. Each bar-shaped component includes a plurality of laser-light-emitting portions that are aligned and integrated in a direction orthogonal to the axis of the solid-state laser rod. The large divergence angle of the stack-type semiconductor can be compensated by including a light focusing component for focusing laser light emitted out of the stack-type semiconductor laser. The focused light is guided by a laser light guiding component disposed in a diffusive reflection tube. A light guiding component guides the focused light onto a solid-state laser rod located within the diffusive reflective tube, while maintaining the length of one side of the cross section of the guided light.

Abstract: Analog pulse position modulation of pulsed emission from a laser, which is actively and harmonically mode-locked. The laser requires: a body of an active gain medium; means for changing the gain as a function of a controllable parameter; harmonically and actively mode-locking the laser by fast periodic changes of said parameter; and superimposing slower changes on the parameter whereby the fast periodic parameter changes can be continuously shifted between the peak and the shoulder of the gain-vs-parameter curve. As proof of concept, electric control of the separation between two interleaved pulse trains from a far-infrared (1.5-4 THz) p-Ge laser, which is actively mode-locked by rf gain modulation at the second harmonic of the roundtrip frequency, is demonstrated by changing the electric bias at the rf contacts. A suggested application is telemetry using analog pulse position modulation.

Abstract: A process and device are provided for stabilizing the emission wavelength of an optical source, which emits radiation at a first wavelength, by locking to the emission wavelength of an optical reference source which emits radiation at a second wavelength which is substantially different from the first. The stabilization device applies to the source to be stabilized a feedback signal obtained by detection of an optical beat between the two radiations. A two-photon absorption for the first wavelength is used to generate the beat.

Abstract: A gas laser device including a dust filter with which a flow rate of laser gas flowing between discharge electrodes is approximately uniform in a longitudinal direction of the discharge electrodes without a variation with time is provided. For this purpose, the gas laser device includes a laser chamber (2) containing laser gas, a pair of discharge electrodes (5, 5) disposed inside the laser chamber (2) to face to each other for exciting a laser medium by discharge to thereby oscillate laser light, a fan (14) for circulating the laser gas to send the same to an area between the discharge electrodes (5, 5), and a dust filter (12) for eliminating dust generated inside the laser chamber (2), and has a configuration in which a filter inlet port (15), which is formed in an inner wall (2A) of the laser chamber (2) and guides the laser gas into the dust filter (12), is formed to be approximately vertical to the inner wall (2A) of the laser chamber (2).

Abstract: A semiconductor emission element is disclosed including a plurality of the laser oscillator formed on the opposite side of a base of a substrate. P-side electrodes are connected to the laser oscillator while extract electrodes having a function of radiation by increasing its thickness, are connected to the p-side electrodes. The extract electrodes cover two of the laser oscillators while covering the other two laser oscillators with insulating layers in between. As a result, thermal interference can be terminated while deterioration of the performance of the emitting portion by generation of heat can be suppressed even if the substrate is provided on the base with the opposite side of the emitting portion of the substrate facing the base.

Abstract: A Q-switch modulator for a high power laser having a randomly polarized output beam and large divergence angle employs a cascaded arrangement of longitudinal mode acousto-optic modulators, each of which has a Raman Nath or near Raman Nath interaction length. The modulators are optically cascaded such that the distance the randomly polarized laser beam travels through the modulators is effectively confined to the sum of the non coherent interaction lengths thereof. Due to the substantial power level of the laser output, there is heating of the bulk material, which usually results in a shift in the Bragg angle. This has minimal if any effect on the shorter interaction length of the Q-switch modulator of the invention. Also, heating of the bulk material is countered by the incorporation of cooling fluid channels in a heat sink support block coupled in thermal communication with the bulk material.

Abstract: A light-emitting device includes a first guide layer; a second guide layer; and an active layer interposed between the first guide layer and the second guide layer. The active layer has a multiple quantum well structure including a plurality of quantum well layers and a quantum barrier layer interposed between the adjacent quantum well layers. The first guide layer and the second guide layer are disposed to be adjacent to the quantum well layers. The first guide layer and the second guide layer have a forbidden band width which is larger than a forbidden band width of the quantum well layers. The forbidden band width of at least one of the first guide layer and the second guide layer is smaller than a forbidden band width of the quantum barrier layer.

Abstract: A laser driving apparatus which includes a plurality of laser emitting elements, a light receiving element for monitoring amounts of light from the plurality of laser emitting elements, and a current-voltage converter for converting a light amount monitor current outputted from the light receiving element to a light amount monitor voltage. The laser driving apparatus also includes a control circuit for controlling a drive current of each of the plurality of laser emitting elements, based on the light amount monitor voltage outputted from the current-voltage converter. The current-voltage converter includes a common resistor and a plurality of non-common resistors, wherein the common resistor is connected to said light receiving element, and each of the plurality of non-common resistors is connectable to the common resistor through a respective switch and is connected to the control circuit.

Abstract: In a process for producing a semiconductor laser device, an n-type cladding layer, an n-type or i-type Inx2Ga1−x2As1−y2Py2 first lower optical waveguide layer, an i-type Inx5Ga1−x5P intermediate layer, an i-type Inx2Ga1−x2As1−y2Py2 second lower optical waveguide layer, an Inx1Ga1−x1As1−y1Py1 compressive strain active layer, a p-type or i-type Inx2Ga1−x2As1−y2Py2 first upper optical waveguide layer, and an Inx5Ga1−x5P cap layer are formed on an n-type GaAs substrate. Then, near-edge portions of the cap layer are etched off with a hydrochloric acid etchant, and near-edge portions of the active region above the intermediate layer are etched off with a sulfuric acid etchant so as to produce spaces in vicinities of end facets. Next, the spaces are filled with a p-type Inx2Ga1−x2As1−y2Py2 second upper optical waveguide layer formed over the cap layer, and a p-type upper cladding layer is formed on the second upper optical waveguide layer.

Abstract: A laser transmission system for transmitting laser beam to an optical fiber comprises a pulse laser oscillator unit, a beam guide unit having an optical condensing unit for condensing a pulse laser beam radiated from the pulse laser oscillator unit, an optical fiber unit for transmitting the pulse laser beam condensed by the optical fiber beam guide unit, and a device for reducing a coherence of the pulse laser beam provided for at least one of the pulse laser oscillator unit, the beam guide unit and the optical fiber unit. This coherence reducing device is for making substantially uniform distribution of laser beams at a beam entrance portion of the optical fiber unit and preventing the laser beams from focussing or converging on one point in the optical fiber unit.

Abstract: An excimer laser device which neither corrodes due to a laser gas nor contaminates the laser gas is provided. For this purpose, in an excimer laser device including a cross flow fan (1) disposed in a chamber (2) for circulating a laser gas, magnetic bearings (12, 12) having outer ring magnet coils (11, 11) and inner ring magnetic substances (10, 10) for rotatably supporting a rotating shaft (9) by magnetic force, and a motor (49) having a stator (47) and a rotor (48) for directly and rotationally driving the cross flow fan (1), the outer ring magnet coils (11, 11), the inner ring magnetic substances (10, 10), the rotor (48), and the stator (47) are respectively housed in shielded spaces shielded from the laser gas.

Abstract: A band narrowing laser having a band narrowing module which narrows by a band narrowing element a band of the laser beam generated from a laser medium, in which wavefront correction means (10) that corrects the wavefront of an incident laser beam and and projects the corrected beam is intalled in the band narrowing module (6) to produce a laser beam with a narrow and stable spectral line width.

Abstract: A wavelength control circuit includes a temperature control loop monitoring the ambient temperature of an LD device and driving an electronic heating and cooling device so that the temperature is constant on the basis of a difference signal between a signal value corresponding to the temperature and a reference signal. In a wavelength control loop, the wavelength of a light signal from the light emitting device is monitored by a wavelength monitor and the electronic heating and cooling device is controlled so that the wavelength is uniform. At power on, the temperature is controlled by the temperature control loop to control LD device wavelength. After the temperature control loop is stabilized, a control is performed with both the temperature control loop and the wavelength monitor.

Abstract: A unique method and apparatus for locking on an absolute wavelength of laser light output by a laser package by actively compensating for a change in the temperature of an etalon optical filter is disclosed. Changes in etalon response characteristics due to temperature changes are compensated for by the addition (or subtraction) of an output voltage offset to the voltage control signal sent to the Thermo-Electric Cooler (TEC) from a controller within the laser package. The voltage offset is calculated by monitoring the etalon temperature. The voltage offset value provides for active compensation of changes in the etalon temperature and effectively “readjusts” the output of the laser as if the etalon temperature itself had been readjusted.

Abstract: A laser driver including a current-output-controlling switch; output-current-generating transistor; current-to-voltage converting transistor; first and second current sources; and current path selector having an input terminal and first and second output terminals. Responsive to a control signal, the selector outputs current through one of these two output terminals. The output current of the second current source is supplied to the current path selector. The output current supplied from the current path selector through the second output terminal thereof and the output current of the first current source are input to the current-to-voltage converting transistor. The output voltage of the current-to-voltage converting transistor is applied between the gate and source of the output-current-generating transistor. Then, the current is output through the drain of the output-current-generating transistor and the current-output-controlling switch.

Abstract: The invention provides a laser system for producing a high energy amplified laser beam output from an oscillator producing a wave front of low energy laser beam, the system including at least one amplifier positioned to receive the low energy laser beam for amplification via a first polarizer; a second polarizer, positioned along the axis of the amplified beam at the output side of the amplifier, for allowing a first fraction of the beam to pass therethrough and for reflecting a second fraction of the beam from an output surface of the polarizer, the second fraction constituting the output of the system; a retroreflector, associated with a quarter wave plate, oriented to receive the first fraction and to reflect it back toward the second polarizer, and reflecting means for reflecting the reflected first fraction toward the first polarizer to be reflected toward the amplifier for further amplification and to be reflected off the output surface of the second polarizer together with the second fraction.

Abstract: A laser array system is described. The system includes a plurality of lasers, a switching mechanism, a wavelength locking mechanism, and a laser parameter feedback control. Each laser provides a collimated beam having certain wavelength and power. The beam has at least two parts, first part of the two parts used for stabilization of the wavelength and power. The switching mechanism is configured to receive and sequentially select the first part of the collimated beam from the plurality of lasers. The wavelength locking mechanism is configured to monitor and measure a drift of the wavelength and power of a selected laser. The laser parameter feedback control is configured to adjust laser parameters of the selected laser.