Abstract: A semiconductor laser element having an advantageous vertical light confinement efficiency, a low threshold current and a low element resistance is provided. The semiconductor laser element has a substrate and a stacked structure formed thereon, where the stacked structure comprises a buffer layer, an n-Al0.6Ga0.4As cladding layer, an n-Al0.47Ga0.53As cladding layer, an active layer, a p-Al0.47Ga0.53As first cladding layer, an Al0.55Ga0.45As etching stop layer, a p-Al0.47Ga0.53As second cladding layer, a p-Al0.6Ga0.4As third cladding layer, and a p-GaAs contact layer. The second and third cladding layers, and the contact layer are formed as a stripe-patterned ridge, and serve as a current injection regions. Both lateral portions of the ridge are filled with an n-type current blocking layer and serve as non-current-injection regions.

Abstract: A semiconductor laser device includes a tailored index single mode power amplifier. A high-power laser system can be produced by connecting several of the tailored index single mode power amplifiers in parallel. In an exemplary case, a phase shifting device can be optically coupled to each of the tailored index single mode power amplifiers; the phase shifting devices can be controlled to ensure that the laser beams output by the tailored index single mode power amplifiers are both phase aligned and wavefront matched.

Abstract: Laser wavelength stabilization is achieved by locating a low selectivity reference filter in a reference path of a laser beam. The low selectivity reference filter, with a periodicity greater than the control filter, is used together with a lookup table for the reference filter to resolve the uncertainty associated with the multivalued control filter. After the wavelength uncertainty for the control filter is resolved, the laser beam is stabilized based on the response of the control filter, as if the reference filter was not present.

Abstract: A semiconductor laser device having an active region including alternating layers of at least one quantum well layer and a plurality of barrier layers, where two of the plurality of barrier layers are the outermost layers of the alternating layers. Each of the at least one quantum well layer has a compressive strain, and each of the plurality of barrier layers has a tensile strain. In the active region, a strain buffer layer having an intermediate strain is formed between each quantum well layer and each of two barrier layers adjacent to the quantum well layer. Interfacial strain is thus reduced, improving high-output-power characteristics.

Abstract: The invention herein is directed to a dual-chamber combustion laser assembly having lighter weight (per unit flow area), a more compact, flexible configuration for packaging in spacecraft, aircraft, or ground mobile vehicles, higher mass efficiency from lower heat loss and proven power extraction efficiency of linear lasers, superior output beam quality by incremental compensation of gain medium optical path disturbances and by reduction in time-dependent variations in structural and gain medium characteristics, lower cost and shorter fabrication time for modular dual flow laser and linear optics, more efficient pressure recovery with side-wall isolation nozzles and compact diffuser configurations, and increased small signal gains for more efficient extraction of overtone power.

Abstract: Laser diodes are formed with an outcoupling grating between two separate distributed Bragg reflectors. The devices have gain regions located between the reflector gratings for pumping the active region. The outcoupling grating couples light out of the waveguide normal to the surface if the grating spacings are equal to an integer number of wavelengths of the light within the cavity. If the gratings are not such an integer number, the light is coupled out of the cavity off the normal.

Abstract: A VCSEL (vertical cavity surface emitting laser) is formed on the top surface of the substrate having an opposed bottom surface. In one exemplary embodiment, the opposed bottom surface is polished and coated with an anti-reflective coating. A photodetector is disposed beneath the bottom surface and is capable of detecting light emitted by the VCSEL. In another embodiment, an angle selective filter is disposed between the photodetector and the unpolished and uncoated bottom surface. The apparatus urges light emitted by the VCSEL to be detected by the photodetector and limits light from other sources from reaching the photodetector. A method for monitoring the optical output of a VCSEL includes providing one of the exemplary apparatuses, causing the VCSEL to emit light that is detected by the photodetector, and adjusting the optical output of the VCSEL based on the amount of light detected by the photodetector.

Abstract: A source of pulses of coherent radiation at a wavelength of approximately 1 ?m, comprises a pump source for producing pump light, a laser cavity comprising an Yb3+-doped gain medium arranged to receive the pump light, the laser cavity being modelocked to generate laser pulses at a defined repetition rate; a pulse detector arranged to generate a pulse selection signal indicative of the repetition rate; a pulse selector arranged to reduce the repetition rate of the laser pulses responsive to the pulse selection signal from the pulse detector by passing only selected ones of the laser pulses; and at least one optical amplifier for amplifying the laser pulses of reduced repetition rate. The at least one optical amplifier can be configured for chirped or parabolic pulse amplification.

Abstract: The invention is directed to a method for the energy stabilization of a gas discharge-pumped radiation source that is operated in defined pulse sequences, particularly for suppression of overshooting and undershooting of excimer lasers and EUV radiation sources in burst operation. It is the object of the invention to find a novel possibility for the stabilization of the energy emission of a gas discharge-pumped radiation source that is operated in defined pulse sequences (bursts) which makes it possible to take into account a temporary behavior of the radiation source at the beginning of every burst without repeated recalibration of the energy-voltage curve.

Abstract: In a gas laser machining apparatus based on a pulse laser oscillation, a mis-pulse-preventing pulse, viz., a preparatory pulse component whose energy is below the threshold value of a laser oscillation, is located prior to a first pulse of discharging power pulses.

Abstract: A vertical cavity surface emitting laser (VCSEL) structure and fabrication method therefor are described in which a subsurface air, gas, or vacuum current confinement method is used to restrict the area of electrical flow in the active region. Using vertical hollow shafts to access a subsurface current confinement layer, a selective lateral etching process is used to form a plurality of subsurface cavities in the current confinement layer, the lateral etching process continuing until the subsurface cavities laterally merge to form a single subsurface circumferential cavity that surrounds a desired current confinement zone. Because the subsurface circumferential cavity is filled with air, gas, or vacuum, the stresses associated with oxidation-based current confinement methods are avoided. Additionally, because the confinement is achieved by subsurface cavity structures, overall mechanical strength of the current-confining region is maintained.

Abstract: An organic vertical cavity laser device includes a substrate; a bottom dielectric stack reflective to light over a predetermined range of wavelengths and being disposed over the substrate, and an organic active region for producing laser light. The device also includes a top dielectric stack spaced from the bottom dielectric stack and reflective to light over a predetermined range of wavelengths, and a thermally conductive transparent layer disposed between the bottom dielectric stack and the organic active region or between the top dielectric stack and the organic active region or both.

Abstract: The invention concerns a tunable edge-emitting semiconductor laser (10) including a resonant cavity delimited by two reflectors (15, 20), one of which is a fixed reflector (15) and the other of which is a mobile reflector (20), and including an active section (1) with gain of length L1 and a tunable section (2) of length L2, characterized in that the total length of the cavity L=L1+L2 is less than or equal to 20 ?m.

Abstract: A self-pulsating semiconductor laser device includes a semiconductor substrate of the first conductivity type, a first cladding layer of the first conductivity type formed on the substrate and an active layer formed on the first cladding layer. A second cladding layer of a second conductivity type is formed on the active layer. A saturable absorbing layer is formed on at least portions of at least one of the first cladding layer and the second cladding layer. The saturable absorbing layer has a band gap energy either approximately the same as, or slightly smaller than, the active layer.

Abstract: A low clad layer made of semiconductor of a first conductivity type is formed on a semiconductor substrate. An active layer is formed on the low clad layer. The active layer is constituted by alternately stacking a strained well layer and a barrier layer. A partial or whole thickness of the active layer is periodically removed along a first direction parallel to the surface of the semiconductor substrate to form a diffraction grating. A filler made of semiconductor is embedded in the removed region. Strain of the strained well layer and strain of the filler have the same sign. An upper clad layer is formed on the active layer and filler and made of semiconductor of a second conductivity type. A semiconductor laser device is provided which has a smaller shift of spontaneous emission or PL even if a diffraction grating is formed in an active layer.

Abstract: A flat or sheet-like electrooptical component for sending and receiving electrical and optical signals includes a central emission region with at least one light-emitting device for sending out optical signals. A sensor region is arranged around the emission region, and at least one device for sensing optical signals is configured in the sensor region. A reflector region is arranged around the sensor region for reflecting incident electromagnetic radiation. The electrooptical component also includes a device for driving the light-emitting device based on incoming electrical signals, and a device for outputting electrical signals based on received optical signals.