Abstract: A mirror for an ultraviolet laser and method of formation such that the mirror is highly reflective to a laser beam generated in the ultraviolet spectrum over a wide range of incident angles and has little fluctuation in polarization reflectivity in relation to a change in an incident angle of the beam. The mirror has a structure comprising an aluminum (Al) film coated over a substrate and a dielectric multi-layer film coated over the aluminum film. The dielectric multi-layer film comprises alternating layers of a low refractive index layer and a high refractive index layer according to the following relationship: L1/[H/L2]x and with an optical thickness according to the following relationship: 2L1=L2≈H=0.25˜0.35&lgr;: or 2L1≈L2=H=0.25˜0.35&lgr;: wherein: L1, L2: represents the low refractive index layers; H: represents the high refractive index layer(s); and X: is an integer between 1 to 10.

Abstract: The invention in one aspect is an optical modulator which includes a waveguide region of semiconductor material. In order to achieve a gradual, essentially linear transfer function, the bandgap of the waveguide region is graded along the direction of light propogation or perpendicular thereto. In accordance with another aspect, the invention is an electroabsorption modulated laser where the portion of the waveguide region defining the modulator has a graded bandgap. In accordance with a method aspect, the waveguide region of the modulator is grown using a mask having a varying width to achieve the graded bandgap.

Abstract: A Group III-V semiconductor optoelectronic device provides for visible wavelength light output having a more laterally uniform, high power beam profile, albeit still quasi-Gaussian. A number of factors contribute to the enhanced profile including an improvement in reducing band offset of the Group III-V deposited layers improving carrier density through a decrease in the voltage drop required to generate carrier flow; reduction of contaminants in the growth of Group III-V AlGaInP-containing layers with compositional Al, providing for quality material necessary to achieve operation at the desired visible wavelengths; the formation of an optical resonator cavity that provides, in part, weak waveguiding of the propagating light; and the utilization of a mechanism to provide for beam spreading and filing in a beam diverging gain section prior to actively aggressive gain pumping of the propagating light in the device.

Abstract: A distributed feedback semiconductor laser including a semiconductor substrate having a bottom surface and a top surface; an active layer formed on the top surface of the semiconductor substrate; a ridge stripe formed on the active layer having a first surface and extending in a first direction; a periodic structure that is periodic in the first direction; a plurality of p-type electrodes formed on the first surface of the ridge stripe; and an n-type electrode formed on the bottom surface of the semiconductor substrate. The first surface of the ridge stripe is parallel with a growth plane of the active layer, the first surface having at least two different widths in a direction perpendicular to the first direction.

Abstract: A GaInAsP/AR GaInP laser diode is provided with an AlGaAs type II carrier blocking layer in the waveguide of the diode. The resulting diode exhibits a relatively low threshold current, an increased slope efficiency and characteristic T0 and T1, for the diodes are less limited by carrier leakage.

Abstract: A method and apparatus for laser diode bar assembly. A stacked array embodiment provides for efficient cooling of the diode bars and electrical connection between diode bars while maximizing alignment of the diode bars. The spacers are connected to a conductive surface on a heat spreader. In the stacked array, one or more diode bars are alternated in series with two or more conductive spacers, with a series circuit provided from diode bar to diode bar. The spacers hold the diodes spaced apart from insulating grooves in the conductive layer on the substrate. Alternatively, thermally conductive separator fins extend from the heat spreader substrate to contact the diode bars situated between the spacers to promote rapid heat transfer from the diodes while maintaining the diode bars electrically isolated from the conductive layer on the substrate. An apparatus and method are provided for assembling the stacked array assembly.

Abstract: A solid state laser includes a solid state laser crystal, a pumping source for pumping the laser crystal, a resonator, an enclosed casing which is filled with gas and in which the resonator is contained, and a temperature controller which keeps the resonator at a predetermined temperature. The ratio of the optical length of the gas layer in the resonator to the oscillation wavelength of the solid state laser is set to be not larger than 13600.

Abstract: A method of fabricating a semiconductor optical device is provided comprising the steps of depositing planar layers of semiconductor material to form a semiconductor wafer having an optically active region, etching through the optically active region to form a plurality of facets, and simultaneously coating at least one facet and an upper surface of the semiconductor wafer with a coating layer having a thickness and composition such that, during operation of the semiconductor device, the coating layer acts both as a facet coating and as a wafer surface coating. Where the coating layer comprises a dielectric, the layer acts both as an anti-reflection facet coating and as a passivating layer. Where the coating layer comprises a metal, the layer acts both as a high-reflectivity facet coating and as an electrical contacting layer. In a first embodiment the semiconductor device comprises a laser and in a second embodiment comprises a photodetector.

Abstract: An apparatus for monitoring and controlling the wavelength of laser radiation includes at a least one optical filter for receiving laser radiation and for transmitting and reflecting first and second filtered beams, respectively. Alternatively, the first and second beams may be transmitted by separate filters. The beams are filtered according to respective first and second spectral filter functions that cross at at least one crossing wavelength. A beam comparison element compares the first and second filtered beams and produces an error signal representative of the deviation of the wavelength of the laser radiation from a set-point wavelength. The beam comparison element can include first and second optical detectors and an error circuit for producing the error signal by taking a ratio or the difference of the signals detected by the detectors.

Abstract: A ring cavity laser has a polyhedral structure contoured by a plurality of planes, and includes a ring cavity having reflective faces formed by the planes of the polyhedral structure, and an active medium. The ring cavity laser is constructed such that there exists a three-dimensional light path among light paths of the ring cavity through which light pumped in the active medium travels when the light starts at a point on one reflective face, is reflected by each reflective face and returns to the starting point.

Abstract: Excimers are generated by directing an electron beam at about 5 KeV to about 40 KeV into an excimer forming gas such as He, Ne, Ar, Kr, and Xe or mixtures of these with other gases through a ceramic foil such as SiNx. Vacuum ultraviolet (VUV) light is emitted by the excimers or by other species in contact therewith. The invention can provide intense, continuously operable broadband or monochromatic VUV light sources.

Abstract: A light-emitting diode has a GaN-based multi-layer structure arranged on a sapphire substrate. A pair of electrode pads are arranged on a light-output face of the multi-layer structure. The first and second electrode pads have a total projected area set at 25% or less of that of the light-output face. The electrode pads are connected to electrode pads on a mount frame by solder wiring layers arranged on an insulating film covering the side wall of the multi-layer structure.

Abstract: A 0.98 &mgr;m semiconductor laser of a ridge waveguide (RWG) structure includes: to be lengthen the durability of a semiconductor laser by increasing a catastrophic optical damage (COD) level, a ridge having a fixed width and length so that the strip may stop in the position of 30 &mgr;m on the basic of end portion of an output facet along length direction of a resonator; and a non-waveguide region in the end portion of both sides of a resonator.

Abstract: Diode type laser devices (diode layers) with nonabsorbing windows that are obtained in low confinement asymmetric structures, that consist of a waveguide and an active region, the action region being situated asymmetrically relative to the waveguide, at an extremity of the waveguide central layer, outside, at the margin or inside the waveguide central layer. The nonabsorbing mirrors can be obtained by the partial etching of the diode lasers layered structures, by this etching the active region being removed but in a large extent the layered structure remaining unaffected, and by the regrowth of a material with an adequate crystalline structure and nonabsorbing for the radiation emitted by the laser. By such a process the optical properties of the waveguide are reconstructed in a large extent, so that the radiation propagates to the mirror into a waveguide similar with the waveguide of the rest of the laser.

Abstract: A Group III-V semiconductor optoelectronic device provides for visible wavelength light output having a more laterally uniform, high power beam profile, albeit still quasi-Gaussian. A number of factors contribute to the enhanced profile including an improvement in reducing band offset of the Group III-V deposited layers improving carrier density through a decrease in the voltage drop require to generate carrier flow; reduction of contaminants in the growth of Group III-V AlGaInP-containing layers with compositional Al, providing for quality material necessary to achieve operation at the desired visible wavelengths; the formation of an optical resonator cavity that provides, in part, weak waveguiding of the propagating light; and the utilization of a mechanism to provide for beam spreading and filing in a beam diverging gain section prior to actively aggressive gain pumping of the propagating light in the device.

Abstract: A three-dimensional waveguiding structure for a microcavity surface-emitting laser is described in which native aluminum oxide layers provide control of intracavity waveguiding and the laser optical mode structure of the emitted beam. Microcavity lasers described herein account for the blueshift of the emission wavelength as the laser lateral dimensions are reduced to or below the emission wavelength.

Abstract: A monolithic, electrically-insulating substrate that contains a series of notched grooves is fabricated. The substrate is then metalized so that only the top surface and one wall adjacent to the notch are metalized. Within the grooves is located a laser bar, an electrically-conductive ribbon or contact bar and an elastomer which secures/registers the laser bar and ribbon (or contact bar) firmly along the wall of the groove that is adjacent to the notch. The invention includes several embodiments for providing electrical contact to the corresponding top surface of the adjacent wall. In one embodiment, after the bar is located in the proper position, the electrically conductive ribbon is bent so that it makes electrical contact with the adjoining metalized top side of the heatsink.

Abstract: A Q-switched laser, which is pumped by at least one pump source (8), providing pulses. The laser comprises two mirrors (3,5) providing a laser cavity, in which a gain medium (2), a saturable absorber (4) and a controllable active modulator (6) is situated. Loss can be introduced in the modulator (6) by a control device (10). In a first phase, said control device (10) introduces loss in the active modulator, setting a threshold inversion density band to a level (B) high enough to be above the actual inversion density in the gain medium means. In a second phase, the control device lowers said loss instantly, which will lower the threshold inversion density band to a level (A) lower than the actual inversion density in order to activate emission of said Q-switched pulse.

Abstract: A saturable Bragg reflector for use in mode locking a laser comprises a stack alternately of layers of a high index of refraction and layers of a low index of refraction. The layers of high index all have optical thicknesses of about one quarter the operating wavelength of the laser. The layers of low index, except for the pair of uppermost layers, have optical thicknesses of a quarter the operating wavelength but that pair have a thickness of about one eighth of a wavelength. A quantum well is located near the center of the layer of high index between the pair of one eighth wavelength. Such a reflector is used as one end of a resonant cavity that houses a gain medium.

Abstract: An apparatus for providing improved high power laser beams. An elongated reflector with a highly-reflective surface is utilized with a laser beam emitter, such as a broad area diode laser, a diode laser bar, or a diode laser array. The laser beams reflect off of the highly-reflective surface which is curved substantially parabolically. The reflected beams are collimated or otherwise shaped and/or coupled by manipulation of the size and shape of the elongated reflector and the placement of the laser beam emitter in association therewith. A system of lenses or mirrors may be used in conjunction with the reflecting apparatus to achieve enhanced beam quality. One-dimensional and two-dimensional laser arrays can also be fabricated utilizing a substrate containing laser beam emitters in communication with one or more grooves formed in the substrate, with parabolic reflecting surfaces formed in the grooves or with optical reflector members placed in the grooves.