Abstract: An infrared element (10a) which includes at least a light emitting layer forming portion (9a) composed of, for example, a first conductivity type cladding layer (2a), an active layer (3a), and a second conductivity type cladding layer (4a) for emitting infrared light, is formed on a semiconductor substrate (1), and a red element (10b) which includes at least a light emitting layer forming portion (9b) composed of, for example, a first conductivity type cladding layer (2b), an active layer (3b), and a second conductivity type cladding layer (4b) for emitting red light, is formed on the same semiconductor substrate (1). And their second conductivity type cladding layers (4a and 4b) are made of the same material. As a result, forming process of their ridge portions may be communized and both of the elements can be formed respectively, with a window structure capable of high output operation.

Abstract: A semiconductor light emitting device includes a first-conductivity-type first multilayer film reflecting mirror, and a second-conductivity-type second multilayer film reflecting mirror; a cavity layer; and a first conductive section, a second conductive section, and a third conductive section. The cavity layer has a stacked configuration including a first-conductivity-type or undoped first cladding layer, an undoped first active layer, a second-conductivity-type or undoped second cladding layer, a second-conductivity-type first contact layer, a first-conductivity-type second contact layer, a first-conductivity-type or undoped third cladding layer, an undoped second active layer, and a second-conductivity-type or undoped fourth cladding layer.

Abstract: An array of optically coupled cavities (called micro-cavities) of a semiconductor laser are defined by either an etch and/or by a native oxide of an aluminum-bearing III-V semiconductor material and are arranged serially end-to-end along the longitudinal direction. An etch and/or native oxide defines a refractive index change for the longitudinal optical mode and confines the optical field within the micro-cavities, resulting in reflection and optical feedback distributed periodically along the laser stripe in the form of an optically coupled micro-cavity. The wavelength of emission of the laser is controlled by a combination of the length of the optical micro-cavities and the spacing between adjacent optical micro-cavities. Single-longitudinal-mode operation is exhibited over an extended drive current range. In one embodiment, two or more linear arrays of end-coupled micro-cavities are arranged in the longitudinal axis of the laser cavity to obtain a tunable laser.

Abstract: An array of optically coupled cavities (called micro-cavities) of a semiconductor laser are defined by either an etch and/or by a native oxide of an aluminum-bearing III-V semiconductor material and are arranged serially end-to-end along the longitudinal direction. An etch and/or native oxide defines a refractive index change for the longitudinal optical mode and confines the optical field within the micro-cavities, resulting in reflection and optical feedback distributed periodically along the laser stripe in the form of an optically coupled micro-cavity. The wavelength of emission of the laser is controlled by a combination of the length of the optical micro-cavities and the spacing between adjacent optical micro-cavities. Single-longitudinal-mode operation is exhibited over an extended drive current range. In one embodiment, two or more linear arrays of end-coupled micro-cavities are arranged in the longitudinal axis of the laser cavity to obtain a tunable laser.

Abstract: A temperature compensating method of laser power in an optical disk storage apparatus is disclosed whereby temperature is compensated so that laser power outputted by a laser diode can be constantly outputted regardless of temperature changes. According to the present invention, a current temperature for operating the laser diode is detected and a linear Equation of a laser power voltage outputted by the laser diode in response to an input current is obtained from the detected current temperature. An input current corresponding to a laser power voltage desired by the obtained linear Equation is calculated and is supplied to the laser diode. Therefore, a laser power desired by the laser diode can be outputted regardless of the temperature changes, thereby enabling to establish an accurate input current.

Abstract: The reliability of a buried hetero-structure semiconductor laser is improved by preventing an increase in oscillation threshold current and a decrease in external differential quantum efficiency in cases where the semiconductor laser is energized continuously under conditions of high temperature and high optical output. An optical semiconductor laser has an optical waveguide structure comprising an n-type cladding layer, an active layer and p-type cladding layers, and a current narrowing/blocking structure comprising a p-type blocking layer and an n-type blocking layer, wherein concentration of hydrogen contained in the p-type cladding layers is higher than concentration of hydrogen contained in the p-type blocking layer.

Abstract: In the surface emitting laser, low threshold electric current and high-power output are achieved while maintaining single mode characteristics. The surface emitting laser comprises a layered structure formed on a GaAs substrate 10 is comprised of: a semiconductor lower DBR mirror 12, a cladding layer 14, a n-type contact layer 16, an active layer 18, an electric current constricting layer 20, a p-type cladding layer 22, a p-type contact layer 24, a phase adjusting layer 36 and a dielectric upper DBR mirror 28. The surface emitting laser should be formed such that the diameter X (?m) of the opening diameter of the previously mentioned electric current constricting layer 20 and diameter Y (?m) of the phase adjusting layer satisfy the following relation: X+1.9??Y?X+5.0? (wherein ? indicates oscillation wavelength (?m) of the surface emitting laser).

Abstract: A spectral purity range (E95) of a laser beam output from an amplifying laser device (300) is measured by spectral purity range measuring means. To have the measured spectral purity range (E95) within an allowable range E950±dE95 of a target spectral purity range (E950), discharge timing from a time when discharge is started by an oscillating laser device (100) to a time when discharge is started by the amplifying laser device (300) is controlled, and the spectral purity range (E95) is controlled to be stabilized.

Abstract: An ultrafast laser for delivering ultra-short duration seed-pulses for further amplification has a resonator including negative group delay dispersion (NGDD) mirrors for minimizing increases in the duration of the pulses due to positive group delay dispersion effects inherent in the resonator. The NGDD mirrors could be configured such that the pulses had a Gaussian spectrum. Instead, however, the NGDD mirrors are configured and arranged such the pulses have a non-Gaussian spectrum. The non-Gaussian spectrum has a FWHM bandwidth significantly greater than that of the Gaussian spectrum.

Abstract: A semiconductor laser device including a submount having a front surface and a back surface corresponding to the opposing face that are in parallel with each other and a visible light transmittance of 60% or more; a connection electrode that is formed on the front surface; and a semiconductor laser element that is packaged on the submount through the connection electrode, and is allowed to emit a laser beam in a direction parallel to the front surface.

Abstract: A driving device including a light emitter, a biasing circuit, a light receiver, an automatic control system, and an alternating current (AC) path is disclosed. The light emitter generates an optical signal. The biasing circuit generates a driving signal to activate the light emitter such that the light emitter operates in a working range. The light receiver detects the output power of the optical signal for generating a corresponding electrical signal. The automatic control system adjusts the driving signal according to the corresponding electrical signal such that the output power of the optical signal approaches a preset value. The AC path is coupled between the light emitter and an external signal source for receiving at least one AC modulated signal such that the light emitter generates at least one modulated optical signal.

Abstract: A mode-locked solid-state laser apparatus having a resonator which includes a solid-state laser medium, a saturable absorption mirror, and a negative group dispersion element therein, in which the solid-state laser medium and the saturable absorption mirror are disposed at a distance not greater than twice a Rayleigh length which is determined by the beam radius of oscillation light formed at the saturable absorption mirror. The apparatus further includes a dichroic mirror in the resonator that reflects excitation light inputted from a direction crossing the optical axis of the resonator toward the solid-state laser medium and transmits oscillation light.

Abstract: A computer may include a database and a power reducing routine. The database may be configured to store an input power level of an input laser beam transmitted onto and storing power within a gain module. The database may be further configured to store a discharge power level of at least partially discharged stored power discharged from the gain module through an output laser beam. The database may also be configured to store a power safety differential limit. The power reducing routine may include an algorithm. The algorithm may be configured to calculate a power differential by subtracting the discharge power level from the input power level, and to at least one of reduce power to and shut down the input laser beam if the calculated power differential exceeds the power safety differential limit.

Abstract: A laser head generating ultrashort pulses is integrated with an active beam steering device in the head. Direct linkage with an application system by means of an adequate interface protocol enables the active device to be controlled directly by the application system.

Abstract: Devices and methods for providing stimulated Raman lasing are provided. In some embodiments, devices include a photonic crystal that includes a layer of silicon having a lattice of holes and a linear defect that forms a waveguide configured to receive pump light and output Stokes light through Raman scattering, wherein the thickness of the layer of silicon, the spacing of the lattice of holes, and the size of the holes are dimensioned to provide Raman lasing. In some embodiments, methods include forming a layer of silicon, and etching the layer of silicon to form a lattice of holes with a linear defect that forms a waveguide configured to receive pump light and output Stokes light through Raman scattering, wherein the thickness of the layer of silicon, the spacing of the lattice of holes, and the size of the holes are dimensioned to provide Raman lasing.

Abstract: A semiconductor laser device is made of a group III nitride semiconductor having a major growth surface defined by a nonpolar plane or a semipolar plane. The semiconductor laser device includes a cavity having an active layer containing In and distributed Bragg reflectors coating both cavity end faces of the cavity respectively. In each of the distributed Bragg reflectors, a central wavelength ?c of a reflectance spectrum satisfies the relation ?SP?10 nm??c??SP+10 nm with respect to an emission peak wavelength ?SP of spontaneous emission in the active layer.

Abstract: A DBR laser, such as a semiconductor DBR laser is disclosed having improved frequency modulation performance. The laser includes a split gain electrode and a tuning electrode. A modulating current encoding a data signal is injected into a first section of the gain electrode whereas a substantially DC bias voltage is imposed on a second section of the gain electrode positioned between the first gain electrode and the tuning electrode. The first and second gain electrodes are electrically isolated from each other and the tuning electrode by a large isolation resistance. In some embodiments, the isolation resistance is generated by forming the electrodes on a P+ layer and removing portions of the P+ layer between adjacent electrodes. Capacitors may couple to one or both of the second gain electrode and the tuning electrode.

Abstract: A laser irradiation apparatus is provided in which the occurrence of adverse effects on an object to be irradiated with a laser beam due to the difference in the polarization state between pulsed laser beams can be prevented or significantly reduced when the pulsed laser beams emitted from two laser light sources are guided to pass through the same optical path for irradiation of an object to be irradiated with the pulsed laser beams. The laser irradiation apparatus is provided with a first laser light source 3, a second laser light source 4, an optical path combining optical member 7 which guides the pulsed laser beams emitted from the first laser light source 3 and the second laser light source 4 to pass through the same optical path, and a polarization control member 9 which controls polarization state of the pulsed laser beam from the optical path combining optical member 7.

Abstract: The present invention relates to a light emitting diode (LED) or a laser diode (2) with a functional element (3) mounted on a light out-coupling side of the LED or laser diode (2) wherein the functional element (3) comprises a provision (5) that allows for electrically contacting the LED or laser diode (2) on the light out-coupling side.

Abstract: In a soliton mode-locked solid-state laser apparatus having a resonator which includes therein a solid-state laser medium, a saturable absorption mirror, and a negative group velocity dispersion element, the solid-state laser medium and saturable absorption mirror are disposed in close proximity to each other at a distance not greater than twice a Rayleigh length. Then, the absorption modulation depth ?R of the the saturable absorption mirror is set to a value not less than 0.4%, and the absolute value |D| (D<0) of a total intracavity dispersion amount D when light having a predetermined wavelength makes one round trip in the resonator, which is represented by the following relational expression, is set within a pulse bandwidth in which operation modes other than a fundamental period soliton pulse can be suppressed by the saturable absorption mirror. ? P = 1.