Abstract: A semiconductor laser diode mounted to a heat sink body has a thermally resistive layer located between the two in order to provide a specified thermal impedance that balances the contrary responses to laser aging and changes in drive current. The required thermal impedance is determined by experimental trial on a plurality of identically mounted test structures differing only in their thermally resistive layer impedances, which are then operated to cause laser aging. The optical mode frequency output from the laser diodes in the test devices are measured under normal operating conditions at least before and after the laser aging, and the thermal impedance value that would result in a substantially zero change in laser output is calculated from these measurements. The resistive layer's thickness and/or doping level may be used to select the desired thermal impedance.

Abstract: A light source device has a semiconductor laser for emitting an elliptical divergent beam having a light intensity distribution in an elliptical form; and a beam shaping element for converting an elliptical divergent beam from said semiconductor laser into an approximately circular divergent beam having a light intensity distribution in an approximately circular form; wherein the beam shaping element has a first surface formed of a cylindrical surface and a second surface formed of an anamorphic surface, in order from said semiconductor laser side, and satisfies the predetermined conditional expressions.

Abstract: An all-silicon nonlinear transmission line (NLTL) is integrated with a pulse-forming circuit in the form of a reverse-biased diode. Relatively short, e.g., 27 ps, optical signals can be generated from the all-silicon NLTL circuit by laser modulation of the electrical NTLT output in an electro-optical system.

Abstract: An external cavity semiconductor laser comprises a grating fiber and a semiconductor optical amplification element. The grating fiber has a Bragg grating and an optical waveguide. The Bragg grating has a frequency fFG and exhibits a maximum reflectivity thereat. The Bragg grating is optically coupled to the optical waveguide. In the external cavity semiconductor laser. The grating fiber is determined such that an oscillation frequency fLD satisfies 0<fFG−fLD<20 GHz  (1) According to the structure of the external cavity semiconductor laser, the occurrence of mode hopping is reduced within a frequency range defined by expression (1).

Abstract: Systems and methods of passivating planar index-guided oxide vertical cavity surface emitting lasers (VCSELS) are described. These systems and methods address the unique susceptibility of these devices to damage that otherwise might be caused by moisture intrusion into the etch holes that are used to form the index-guiding confinement regions. In one aspect, the invention features a VCSEL that includes a vertical stack structure having a substantially planar top surface. The vertical stack structure includes a top mirror, a bottom mirror, and a cavity region that is disposed between the top mirror and the bottom mirror and includes an active light generation region. At least one of the top mirror and the bottom mirror has a layer with a peripheral region that is oxidized into an electrical insulator. The vertical stack structure defines an etched hole that extends from the substantially planar top surface to the oxidized peripheral region.

Abstract: A laser with a decoupling device for emitting a laser output depending on at least one influenceable parameter and a mode-coupling device for coupling a plurality of the laserable modes of the resonator. A detector is provided for detecting a value related to the emitted laser output and a parameter varying means for varying the at least one parameter in response to the detected value.

Abstract: A passive mode lock fiber laser including an energy generating means. The energy generating means includes a cavity, the cavity includes a gain medium made of an optical fiber for amplifying the laser energy in the cavity, a reflect means for reflecting the laser energy, a phase fluctuation compensating means for compensating a linear phase fluctuation of the gain medium, and an output means for outputting the laser energy generated in the cavity includes a temperature adjusting mechanism for adjusting a temperature of an optical fiber portion and a piezo element position adjusting mechanism for adjusting a position in the optical axis of the reflect means by using a piezo element.

Abstract: A single frequency filter for a laser, comprising a polarizer that defines a direction of polarization and one or more birefringent elements situated within the cavity with their dielectric axes offset from the direction of polarization. The ends of the birefringent elements have a finite reflectance, and may be coated for reflectance or left uncoated. In some embodiments the filter is situated in a laser cavity with a broadband gain medium, in other embodiments, the filter is situated in an external cavity. To provide tunability, a wavelength control system is coupled to the birefringent element. An embodiment is described in which the filter comprises two birefringent elements of unequal optical length along the optical axis, which advantageously reduces the voltage required to tune the frequency. To provide tunability, the first and second birefringent elements are both coupled to a wavelength control system that simultaneously controls both elements.

Abstract: The invention relates to a device having touch sensitivity functionality, comprising a surface (2), touch-sensitive means (5) for detecting the presence of a touch input member (6) being in contact with or close to the surface (2) generating a distance sensor signal. Since conventional resistive or capacitive touch-sensitive layers have a limited transparency, they significantly reduce the screen quality. According to the invention, a display device having touch sensitivity functionality is provided without adding a layer to the display, and is characterized in that the touch-sensitive means (5) comprises means (51) for emitting a laser beam (4, 8) in a plane parallel and close to the surface (2), said laser beam being periodically deflected across the entire surface (2), and means (51, 60) for receiving the light reflected or scattered from the touch input member (6) generating said distance sensor signal therefrom.

Abstract: In a semiconductor laser element, a lower cladding layer of a first conductive type, a GaAs first optical waveguide layer of the first conductive type or an undoped type, an InGaAsP or InGaAs compressive-strain active layer, a GaAs second optical waveguide layer of a second conductive type or an undoped type, and an upper cladding portion are formed on a GaAs substrate of the first conductive type. The active layer is not formed in at least one vicinity of at least one end facet, and the space in the at least one vicinity of the at least one end facet is filled with a third optical waveguide layer of the second conductive type or an undoped type, where the bandgaps of the first, second, and third second optical waveguide layers are greater than the bandgap of the active layer.

Abstract: According to the present invention, there is provided a light scattering type particle detector, using a semiconductor laser as a light source, for detecting particles contained in sample fluid which defines a flow path, wherein laser light generated from the semiconductor laser is irradiated to irradiate a region of the flow path with a concave mirror and thereby a particle detecting region is defined. According to the present invention, there is also provided a laser oscillator wherein the optical axis of a semiconductor laser for generating pumping laser light has a predetermined angle with respect to the optical axis of a laser medium for irradiating laser light by pumping. Using such a laser oscillator, laser light irradiated from the laser oscillator is condensed to irradiate a region of a flow path defined by sample fluid, and thereby a particle detecting region is defined. Particles contained in the particle detecting region are detected by receiving scattered light with a light receiving portion.

Abstract: A semiconductor laser device has a quantum well active layer including a well layer and a barrier layer laminated on a semiconductor substrate. The quantum well active layer contains II group atoms such as Zn atoms. The quantum well active layer is so formed that a bandgap of the quantum well active layer in the vicinity of an end surface of a laser resonator is larger than a bandgap of the quantum well active layer inside the laser resonator. The II group atoms contained in the quantum well active layer inside the laser resonator make up for vacancies introduced therein so as to inhibit fluctuation of the bandgap of the quantum well active layer inside the laser resonator and thereby to enhance long-term reliability of the semiconductor laser device.

Abstract: A housing adapted to position, support, and facilitate aligning various components, including an optical path assembly, of a laser. In a preferred embodiment, the housing is constructed from a single piece of material and broadly comprises one or more through-holes; one or more cavities; and one or more integral mounts, wherein the through-holes and the cavities cooperate to define the integral mounts. Securement holes machined into the integral mounts facilitate securing components within the integral mounts using set screws, adhesive, or a combination thereof. In a preferred method of making the housing, the through-holes and cavities are first machined into the single piece of material, with at least some of the remaining material forming the integral mounts.

Abstract: A nonlinear polarization amplifier stage includes a gain medium operable, to receive a multiple wavelength optical signal. The amplifier stage also includes a pump assembly operable to generate at least one pump wavelength for introduction to the gain medium. The amplifier stage further includes a coupler operable to introduce the at least one pump wavelength to the gain medium to facilitate amplification of at least a portion of the multiple wavelength optical signal through nonlinear polarization. In one particular embodiment, at least a wavelength or an intensity of the at least one pump wavelength is manipulated to affect the shape of a gain curve associated with the multiple wavelength optical signal in the amplifier stage.

Abstract: A semiconductor laser device including a semiconductor laser element, a temperature measuring element to measure a temperature, and a temperature regulating unit having the laser element and the temperature measuring element thermally connected thereto. The laser device includes a current detecting unit to detect a driving current applied to the laser element, and a control unit to control the temperature regulating unit using a control function to achieve a substantially constant wavelength output from the laser element. The control function defines a relationship between a predetermined driving current and a predetermined temperature. The control unit is configured to control the temperature regulating unit such that the detected temperature substantially equals the predetermined temperature corresponding to the detected driving current as defined by the control function.

Abstract: A novel laser apparatus is disclosed which pertains to laser resonator geometries possessing circular symmetry, such as in the case of disk or spherical lasers. The disclosed invention utilizes multi-layer dielectric (MLD) thin film reflectors of many layer pairs of very small refractive index difference, the MLD deposited on a surface of revolution, thereby forming an optical cavity. These dielectric reflectors are disposed in such a way as to allow selection of preferred low order modes and suppression of parasitic modes while allowing a high cavity Q factor for preferred modes. The invention disclosed, in its preferred embodiments, is seen as particularly useful in applications requiring high efficiency in the production and coupling of coherent radiation. This is accomplished in a cavity design that is relatively compact and economical.

Abstract: A wavelength monitor comprises a cylindrical lens configured to allow a laser beam emitted from a semiconductor laser to pass therethrough, first and second photodetectors configured to receive the laser beam through the cylindrical lens, and a wavelength filter disposed in an optical path between the semiconductor laser and the first photodetector.

Abstract: A vertical cavity surface emitting laser (VCSEL) capable of producing long-wavelength light has a substrate of InP and an active region with alternating quantum wells and barrier layers. The target wavelength range is preferably between 1.2-1.4 um. The quantum well is made of AlGaAsSb or GaAsSb, and the barrier layers are made of AlGaAsSb, AlInGaAs, or AlInAs. The active region is sandwiched between two mirror stacks that are preferably epitaxially grown Distributed Bragg Reflectors. The active region has large conduction and valence band offsets (&Dgr;Ec and &Dgr;Ev) for effective carrier containment over the wide range of ambient temperatures in which the VCSEL is expected to function. The active region can be designed to have little or no lattice strain on the InP substrate.

Abstract: VCSELs having upper mirror structures comprised of a semiconductive top DBR, metal contacts, and a top mirror. The top DBR is thick enough for adequate current spreading, but thin enough, being no more than 3.5 microns, to enable easy fabrication of an isolation region. The top mirror, which is over the top DBR, enhances reflectivity. That top mirror is beneficially comprised of a dielectric material, such as TiO2; TiO2+SiO2 (robust and reliable); TiO2+Al2O3 (good thermal conductivity); or Si+MgO, or of a metal. The top mirror is beneficially formed using a vacuum deposition method, such as e-beam or sputtering. The metal contacts are formed on the top DBR. The VCSELs further include a substrate with an electrical contact, a bottom DBR, a bottom spacer, an active region, and a top spacer. Such VCSELs are particularly beneficial at long wavelengths.

Abstract: An excimer laser with a purged beam path capable of producing a high quality pulsed laser beam at pulse rates in excess of 2,000 Hz at pulse energies of about 5 mJ or greater. The entire purged beam path through the laser system is sealed to minimize contamination of the beam path. A preferred embodiment comprises a thermally decoupled LNP aperture element to minimize thermal distortions in the LNP. This preferred embodiment is an ArF excimer laser specifically designed as a light source for integrated circuit lithography. An improved wavemeter is provided with a special purge of a compartment exposed to the output laser beam.