Abstract: A semiconductor light emitting device comprises: a stacked body of semiconductor including an active layer; a ridge stripe protruding and extending in a first direction on a first major surface of the stacked body; dummy ridges protruding on the first major surface of the stacked body on both sides of the ridge stripe; and a slit formed on the first major surface of the stacked body. The ridge stripe includes at least a portion of a waveguide that guides light emission generated by injected current. The slit extends along a second direction which crosses the first direction, and divides one of the dummy ridges.

Abstract: A cooling system for use in with a transmissive optical element of a high average power laser (HAP). The system includes at least one optically transmissive element (TOC) that is held by a differential pressure in thermal contact with a heat sink assembly. In one embodiment, the heat sink assembly includes an optically transparent heat conductor (THC) attached to at least one face of the TOC. A vacuum formed between adjacent faces of the TOC and THC urges the facing planar surfaces into thermal contact with one another. Waste heat generated in the TOC is conducted to the THC. The temperature gradient inside the TOC is maintained substantially parallel to the direction of a laser beam being directed through the THC so that a given phase front of the beam exposes TOC material to the same temperature. As a result, the TOC does not perturb the phase front of the laser beam.

Abstract: Intersubband semiconductor lasers (ISLs) are of great interest for mid-infrared (2-20 ?m) device applications. These semiconductor devices have a wide range of applications from pollution detection and industrial monitoring to military functions. ISLs have generally encountered several problems which include slow intrawell intersubband relaxation times due to the large momentum transfer and small wave-function overlap of the initial and final electron states in interwell transitions. Overall, the ISL's of the prior art are subject to weak intersubband population inversion. The semiconductor device of the present invention provides optimal intersubband population inversion by providing a double quantum well active region in the semiconductor device. This region allows for small momentum transfer in the intersubband electron-phonon resonance with the substantial wave-function overlap characteristic of the intersubband scattering.

Abstract: In a semiconductor laser apparatus, semiconductor laser devices are mounted on a loading face of a radiation base portion produced from a radiation material in a mount board, and the radiation base portion and a cap portion constitute an envelope surrounding the semiconductor laser devices. Further, the radiation base portion and interconnections formed on and an extending face of the radiation base portion constitute an external connection terminal. Therefore, heat generated by the semiconductor laser devices is efficiently transferred to the radiation base portion produced from a radiation material. Further, constituting the external connection terminal allows a leadless configuration to be implemented. Thus, a semiconductor laser apparatus which is sufficient in radiation characteristics and is capable of supporting a low-profile specification is provided.

Abstract: An inexpensive laser drive device which is capable of driving a laser for emission of an appropriate amount of light. Electric currents supplied from a supply current control device formed in an integrated circuit to a plurality of predetermined ports of the integrated circuit are turned on and off by switching devices in response to a signal from a signal output device of the supply current control device, and the on currents are supplied, as a driving current, from the supply current control device to a laser beam-emitting device through corresponding ones of the predetermined ports and resistors externally attached to these ports. A generator device formed in the integrated circuit generates a pulse signal for turning on and off a laser beam based on image data.

Abstract: Saturated tabletop lasers having increased output energy and operating at 5 Hz repetition rate, were demonstrated at wavelengths about 18.9 nm for molybdenum targets, 16.4 nm for ruthenium targets, 14.7 nm for palladium targets, 13.9 nm for silver targets, and 13.2 nm for cadmium targets in transitions of nickel-like ions. The results were obtained using a sequence of two, plasma-generating pre-pulses, each having sub-Joule energy followed after a selected delay period by picosecond laser plasma excitation pulses having with an energy of about 1 J at angles of incidence optimized for maximum energy deposition.

Abstract: A system and method for controlling the temperature of a heat-generating component such as a laser. A microelectromechanical system for controlling the temperature of the heat-generating component includes a magnetic heat sink device, a temperature sensor, and control circuitry. The temperature sensor detects the temperature of the heat-generating component through the heat sink and feeds the sensed temperature to the control circuitry. The detected temperature is compared to a predetermined temperature set point. When the detected temperature is higher than the temperature set point, a command is sent to the magnetic heat sink to take more heat out of the heat-generating component. When the detected temperature is lower than the temperature set point, a command is sent to the magnetic heat sink to take less heat out of the heat-generating component.

Abstract: Provided are a semiconductor laser module and a method of assembling the same. The semiconductor laser module comprises a first semiconductor optical element and a second semiconductor optical element as a pair and a lens. The first semiconductor optical element is for outputting light signal and the second semiconductor optical element is for performing signal processing on the light signal outputted from the first semiconductor optical element. The lens is for correcting a relation between optical axes of the first semiconductor optical element and the second semiconductor optical element so as to lens-couple the optical axes. The first semiconductor optical element, the second semiconductor optical element and the lens are mounted on a common element carrier.

Abstract: A laser diode assembly has a laser diode. The laser diode has an emitting surface and a reflective surface opposing the emitting surface. The laser diode has first and second side surfaces between the emitting and reflective surfaces. A first electrically-insulating heat sink is attached to the first side surface of the laser diode via a first solder bond, and the first heat sink has a first cooling channel. A second electrically-insulating heat sink is attached to the second side surface of the laser diode via a second solder bond, and the second electrically-insulating heat sink has a second cooling channel. A substrate has a top side and a bottom side, and the top side being in communication with a first bottom side of the first electrically-insulating heat sink and a second bottom side of the second electrically-insulating heat sink. The substrate has a flow channel system for passing a coolant to the first cooling channel and the second cooling channel.

Abstract: In a semiconductor optical device, the semiconductor substrate has a primary surface intersecting with a predetermined axis. The lower cladding region of the first conductive type is provided on the primary surface thereof. The lower cladding region includes ridge regions and a base region. The base region has first portions and second portions. The first portions and the second portions are alternately arranged along a predetermined plane perpendicular to the predetermined axis. Each first portion extends in an optical propagating direction. Each second portion extends in the optical propagating direction. Each ridge region is located on each second portion. Each ridge region has a side and a top, and each first portion has a top. The upper cladding layer of the second conductive type is provided on the primary surface of the semiconductor substrate. The bulk active layer is provided between the upper cladding layer and the lower cladding region.

Abstract: A surface emitting semiconductor laser includes a substrate, at least one light-emitting element on the substrate, and at least one protection element on the substrate. The light-emitting element includes a first semiconductor layer of a first conduction type electrically connected to a first electrode, and a second semiconductor layer of a second conduction type electrically connected to a second electrode. The protection element includes a third semiconductor layer of the first conduction type electrically connected to a third electrode, and a fourth semiconductor layer of the second conduction type electrically connected to the second electrode. The first semiconductor layer and the first electrode are electrically isolated from the third semiconductor layer and the third electrode by insulation means.

Abstract: Data transmitter circuitry on a programmable logic device (“PLD”) includes a plurality of channels of serializer circuitry, and a plurality of clock multiplier units (“CMUs”), each of which is associated with a respective subplurality of the serializer channels. Each CMU includes multiple reference clock signal sources, multiple phase-locked loop (“PLL”) circuits, and circuitry for allowing any PLL to get its reference input from any of the reference sources. Raw and centrally processed clock signals produced by each CMU are distributed to the serializer channels associated with that CMU and, at least in the case of the centrally processed signals, to the serializer channels associated with another CMU. The signal that controls release of parallel data to each serializer channel can be an output signal of that channel, or it can be an output signal of any CMU from which that channel can get a clock signal.

Abstract: When a tunable laser is operating at any one of the different wavelengths, wavelength data is sampled and stored in a memory device. In the case where the same operating wavelength as a wavelength hitherto operated needs to be reset to the tunable laser, the wavelength data stored in the memory device is set to the tunable laser. This makes it possible to avoid a shift in wavelength due to age degradation of the tunable laser that selectively outputs any one of light signals of different wavelengths in dependence on the wavelength data set to the tunable laser.

Abstract: A unipolar semiconductor laser is provided in which an active region is sandwiched in a guiding structure between an upper and lower cladding layer, the lower cladding layer being situated on a semiconducting substrate. The unipolar semiconductor laser comprises a raised ridge section running from end to end between end mirrors defining the laser cavity. The ridge section aids in optical and electrical confinement. The ridge waveguide is divided in a plurality of cavity segments (at least two). Lattice structures can be arranged on and/or adjacent to these cavity segments. Each cavity segment is in contact with upper metallic electrodes. A metallic electrode coupled to the bottom surface of the semiconducting substrate facilitates current injection through the device.

Abstract: A plurality of subresonators (12, 14), having different design configurations, share a common resonator section (18) such that the lasing action can be substantially synchronized to provide coherent laser pulses that merge the different respective pulse energy profile and/or pulse width characteristics imparted by the configurations of the subresonators (12, 14). The subresonators (12, 14) may share a laser medium (42) in the common section, or each distinct subresonator section (28, 36) may have its own laser medium (42). Exemplary long and short subresonators (12, 14) generate specially tailored laser pulses having a short rise time and a long pulse width at one wavelength or two different wavelengths that may be beneficial for a variety of laser and micromachining applications including memory link processing.

Abstract: An optical signal emitted from a semiconductor laser is converged by a lens and then received by a single uniaxial birefringent crystal having a C axis that is inclined at an angle other than 90 degrees against a laser optical axis to output an optical signal having a polarized wave component of constant intensity corresponding to the wavelength of the optical signal regardless of temperature changes. The optical signal has an ordinary ray vibrating in a direction perpendicular to a plane including both the C axis and the laser optical axis, and an extraordinary ray vibrating in a direction perpendicular to both the ordinary ray and the laser optical axis. A first main photo detector detects the intensity of a p-polarized component of the optical signal that has passed through a polarizer and a second photo detector directly receives the optical signal converged by the lens.

Abstract: In a laser module comprising a hermetically sealed container having inside a semiconductor laser device whose emission wavelength is 350˜450 nm, generation of organic volatile gas is suppressed in the container and life of the module is prolonged. In a laser module comprising a hermetically sealed container having inside a semiconductor laser device whose emission wavelength is 350˜450 nm and whose life is 5500 hours or more, optical components whose organic volatile gas generation measured by GC/MS is 10 ?g/g or less at 150° C. are positioned in the container. In addition, as an organic adhesive to fix the optical components such as a collimating lens is used an organic adhesive whose organic volatile gas generation measured by GC/MS is 300 ?g/g or less at 15° C.

Abstract: In a semiconductor laser element: a lower cladding layer of In0.49(Alx1Ga1-x1)0.51(x2<x1<1) of a first conductive type which lattice-matches with GaAs; a lower optical waveguide layer of In0.49(Alx2Ga1-x2)0.51P (0<x2<x1) which lattice-matches with GaAs; an active layer; an upper optical waveguide layer of In0.49(Alx2Ga1-x2)0.51P (0<x2<x1) which lattice-matches with GaAs; and an upper cladding layer of In0.49(Alx1Ga1-x1)0.51P (x2<x1<1) of a second conductive type which lattice-matches with GaAs are formed in this order on a substrate of GaAs. The total thickness of the lower optical waveguide layer, the active layer, and the upper optical waveguide layer is 0.30 micrometers or greater.

Abstract: A semiconductor laser driving circuit includes a light amount detector, a frequency determiner, and an initialization circuit. The light amount detector detects an amount of light emitted by a laser diode, and outputs a first voltage corresponding to the amount of light. The frequency determiner determines a frequency for determining a time period of a detecting operation to detect differential quantum efficiency of the laser diode. The initialization circuit performs an initialization operation to detect differential quantum efficiency of the laser diode with a variation of the time period of the initialization operation according to the frequency determined by the frequency determiner.

Abstract: A heavy metal oxide glass selected from germanate, tellurite and bismuth oxide glasses provides a host for highly efficient Thulium doped 2 ?m oxide glass and fiber lasers. The concentration of Thulium ions is high enough that energy transferred by the phenomenon of cross-relaxation will enhance laser emission at 2 ?m and suppress emission at 1.5 ?m so that 2 ?m emission is dominant.