Abstract: A laser device which may be used as an oscillator or amplifier comprising a chamber having a volume formed therein and a gain medium within the volume. The gain medium comprises solid-state elements containing active laser ion distributed within the volume. A cooling fluid flows about the solid-state elements and a semiconductor laser diode provides optical pump radiation into the volume of the laser chamber such that laser emission from the device passes through the gain medium and the fluid. The laser device provides the advantages of a solid-state gain medium laser (e.g., diode-pumping, high power density, etc), but enables operation at higher average power and beam quality than would be achievable from a pure solid-state medium.

Abstract: A multi-wavelength semiconductor laser is formed by monolithically integrating a plurality of laser diodes (1, 2) with at least one isolator section (3) and a coupler (4), which couples the different emission wavelengths ?1, ?2 into one output port (5). The isolator section can be either a light absorptive type or wavelength selective type, including a Bragg grating type isolator or a photonic bandgap crystal type isolator. The coupler is preferably a Y-junction coupler, but can also be a multi-branch waveguide coupler or a waveguide directional coupler.

Abstract: This invention relates to the field of lasers and in particular to the pump sources used in lasers. Many existing lasers use linear flashlamps in order to create population inversion in the gain medium of the laser. Such pump sources suffer from a number of drawbacks particularly when pumping dye lasers including explosive damage, long optical pulse length and inappropriate spectral emission. This invention provides a pump source for a laser which exploits the surface discharge phenomenon. A dielectric material (1) which is in contract with a gas (9) has electrical energy discharged across its surface in order to provide an electromagnetic emission which is then used to pump the gain medium. By varying the dielectric material or the cover gas used (amongst other variables) the surface emission can be used to pump the laser gain medium.

Abstract: An opto-electronic oscillator including a modulator for outputting modulated light and a tunable filter for receiving modulated light output from the modulator.

Abstract: An on-board antenna comprising a radiation element provided on a dielectric substrate, a grounding conductor surrounding a periphery of an outer edge portion of the radiation element at a position spaced away outwardly from the outer edge portion, a substantially box-shaped reflecting member including an opening thereof. The opening of the reflecting member is closed by the surface of the dielectric substrate so as to face the radiation element, and a conductive member is provided at least partially on an inner surface of the reflecting member.

Abstract: A tri-mode co-boresighted seeker including a primary collecting mirror assembly having a parabolic surface and a forwardly located dielectric secondary mirror assembly including a dielectric mirror coating which reflects infrared (IR) energy to an IR detector assembly located on a central longitudinal axis on one side of the secondary mirror while providing substantially unobstructed propagation of millimeter wave RF energy and laser energy in a joint or common signal path therethrough to means located on the other side of the secondary mirror for extracting and diverting laser energy away from the common RF-optical signal path to a laser sensor assembly while causing little or no disturbance to the RF signal as it propagates to a co-located bifurcated waveguide assembly which couples the RF energy to an RF sensor means located behind the primary mirror.

Abstract: A semiconductor laser device comprises a laminate consisting of a semiconductor layer of first conductivity type, an active layer and a semiconductor layer of second conductivity type, which is different from the first conductivity type, that are stacked in order, with a waveguide region being formed to guide a light beam in a direction perpendicular to the direction of width by restricting the light from spreading in the direction of width in the active layer and in the proximity thereof, wherein the waveguide region has a first waveguide region and a second waveguide region, the first waveguide region is a region where light is confined within the limited active layer by means of a difference in the refractive index between the active layer and the regions on both sides of the active layer by limiting the width of the active layer, and the second waveguide region is a region where the light is confined therein by providing effective difference in refractive index in the active layer.

Abstract: In laser-plasma generation, a fluid of target material is jet out to form a jet tube target 21 having a diameter ? and a wall thickness ? with a shell and a hollow space within the shell by using a core-column. A plurality of pulse-like laser beams 30 are directed to the jet tube target radially and equiangularly-spaced directions and are simultaneously focused and irradiated onto the jet tube target to generate the plasma.

Abstract: A control system architecture that allows a semiconductor laser to be stabilized with respect to critical parameters, such as output power and/or emission wavelength, with a reduced cost with respect to the components required to implement control, while simultaneously maintaining or increasing precision of the control function. This is achieved using sophisticated integrated circuitry contained within the laser package to measure data related to multiple laser operation parameters and to transmit these parameters to a control circuit. In particular, precision thermal measurements may be used to eliminate the need for optical detectors in the laser package. The invention described herein has significant utility for different types of semiconductor lasers, including both edge emitting and VCSEL-type semiconductor lasers.

Abstract: A method for controlling a laser includes determining an average component of a laser drive current and adjusting a modulation component of the drive current based on the average component and a threshold current signal at the present temperature. Determining the average component includes adjusting the drive current until an output power of the laser is approximately equal to a reference signal that varies according to temperature. The method further includes calibrating the threshold current signal, which includes adjusting the drive current until the laser output power is approximately equal to a second reference signal, and storing the drive current signal as the threshold current signal at the present temperature. The method further includes recalibrating the threshold current signal, which includes storing a difference between a new value and a stored value of the threshold current signal as an offset for other stored values of the threshold current signal.

Abstract: A laser level disposable on a reference surface includes a housing, a pendulum pivotably connected to the housing, a first laser diode disposed on the pendulum for emitting a first laser beam along a first path, and a lens disposed on the pendulum in the first path for converting the first laser beam into a first planar beam, the first planar beam forming a line on the reference surface.

Abstract: A laser process system with multiple, independently steerable laser beamlets and including a laser and beam shaper for generating a shaped source beam, a splitter stage for generating a plurality of beamlets from the shaped source beam, a beamlet controller including an independently steerable beamlet steering mirror for and corresponding to each beamlet for independently directing the corresponding beamlet, a mirror controller for controlling each beamlet steering mirror, and an optical path including a scanning lens for directing each steered beamlet to a target area of a workpiece. Each beamlet steering mirror is a multi-axis micro-electro-mechanical mirror and the system further includes a beam dump located in the optical path for intercepting a beamlet steered into the beam dump by the corresponding beamlet steering mirror.

Abstract: A receiver receives an electromagnetic signal via an antenna mounted on an antenna mast. A signal evaluator determines or measures a signal quality level associated with the received electromagnetic signal. The signal quality compares the determined signal quality level to a threshold minimum signal quality level. A current elevational position of the antenna mast is detected or tracked. The antenna mast is raised to a greater height than the current elevational position if the compared signal quality level is less than the threshold minimum signal quality level and if the current elevational position is less than a maximum height of the antenna mast.

Abstract: An exposure apparatus has a laser device that is small, easy to maintain, and capable of producing an output that is unlikely to be affected by optical surges occurring in the beginning of operation. A single-wavelength laser oscillator (11) supplies a laser beam (LB1) to a fiber optic amplifier (13) through an optical modulator (12). The amplified laser beam is split by splitters (14, 16-1 to 16-m), amplified by optical amplifier units (18-1 to 18-n) and supplied through a fiber bundle (19) to a wavelength converter (20), which in turn converts the split beams into ultraviolet laser radiation (LB5) for use as exposure light. The optical modulator (12) outputs light pulses during the generation of ultraviolet light. The optical modulator (12) also produces laser radiation during the absence of ultraviolet light, but the laser radiation has substantially the same average output and a considerably low peak compared with that during the generation of ultraviolet light.

Abstract: An optical medium having a cavity that defines a variable gap is provided. The optical medium is used in an optical sensor, laser, and variable frequency resonator, by way of example. The cavity is physically altered in response to changes in a measurable parameter like pressure, temperature, force, flow rate, and material composition. The optical medium is characterized in some embodiments by having a cavity disposed near or within a high Q optical resonator. The optical resonator can be formed by various structures of which Bragg reflector cavities, ring resonators, microdiscs, and microspheres are examples. The optical resonator is preferably coupled to a laser source. The altering of the cavity affects the resonance condition within the optical resonator and thereby the laser signal of the system. If the laser source is a mode locked laser, the repetition rate of the pulse train changes in response to changes in the measurable parameter.

Abstract: A method for determining a condition of the laser system includes determining a change in a laser current from an initial value. A method for measuring a laser current includes determining a difference between the values of a power supply current, which is the value of the laser current. A method for measuring a transmitted power includes generating a first control signal that sets a magnitude of a bias current supplied to a laser, generating a second control signal that sets a of a modulation current supplied to the laser, and determining a difference between values of a high and a low transmitted powers. A method for measuring a received optical power includes determining a received OMA corresponding to the power signal, which is the transmitted OMA minus a known loss through a calibration fiber that couples the laser transmitter to the laser receiver.

Abstract: A method for compensating thermal optical effects in the beam path of an arrangement containing optical components uses, for the purpose of optical compensation in the beam path, optical elements which have different material properties in cooperation. For the purpose of compensation, heating by means of radiation absorption, radial thermal conduction for generating a power-dependent temperature distribution, and/or thermal dispersion for generating a thermal lens are distributed over the different elements.

Abstract: A vertical cavity surface emitting laser (VCSEL) device with improved power and beam characteristics. The VCSEL device contains one VCSEL or an array of VCSELs. Each VCSEL has a corresponding integrated microlens, and a heat sink is attached to the device side of the VCSEL device. The heat sink allows improved heat dissipation, and therefore provides improved power characteristics of the VCSEL device output laser beam. The microlens or microlens array allows easier and more compact focussing of the VCSEL device output laser beam. The VCSEL device can be used in a variety of optical systems, and its improved power and focusing characteristics provide a compact, low power, low cost laser system.

Abstract: A laser control circuit comprises a temperature control circuit and a data processing circuit. The temperature control circuit adjusts the temperature of a laser diode by controlling a temperature regulator. The data processing circuit receives the output of a wavelength monitor. The data processing circuit first adjusts the, temperature of the laser diode to a temperature value previously associated with the target wavelength. Then the data processing circuit finely adjusts the temperature of the laser diode according to the output of the wavelength monitor. Because rough adjustment has been carried out, it is not necessary to change the wavelength significantly according to the output of the wavelength monitor. Therefore, the periodic wavelength dependence of the output of the wavelength monitor does not decrease the accuracy of the control.

Abstract: A loop antenna is formed on one side of a circuit board and an IC chip is mounted on the same side of the circuit board. An inner end of the loop antenna is connected to an antenna connection terminal of the IC chip. An arm part provided with a first pad part, a second pad part, and a conducting wire for allowing conduction between the fist pad part and the second pad part is collapsibly provided in such a manner that, when the arm part is collapsed, an outer end of the loop antenna contacts the first pad part and an antenna connection terminal of the IC chip contacts the second pad part.