Abstract: A method using a safety system and a safety system for localizing at least one person or at least one object in a monitored zone, having at least one control and evaluation unit, having at least one radio location system, wherein the radio location system has arranged radio stations; wherein position data of the person or object can be determined by means of the radio location system; wherein the monitored zone has a plurality of sectors and a plurality of passage zones between the sectors, at least one spatially resolving sensor is associated with each passage zone, and wherein the control and evaluation unit is configured to cyclically compare the position data of the radio location system and the presence data of the spatially resolving sensor in each respective passage zone and to cyclically form status information for the sector.

Abstract: A light-emitting element includes a mesa structure in which a first compound semiconductor layer of a first conductivity type, an active layer, and a second compound semiconductor layer of a second conductivity type are disposed in that order, wherein at least one of the first compound semiconductor layer and the second compound semiconductor layer has a current constriction region surrounded by an insulation region extending inward from a sidewall portion of the mesa structure; a wall structure disposed so as to surround the mesa structure; at least one bridge structure connecting the mesa structure and the wall structure, the wall structure and the bridge structure each having the same layer structure as the portion of the mesa structure in which the insulation region is provided; a first electrode; and a second electrode disposed on a top face of the wall structure.

Abstract: A laser apparatus includes a master oscillator capable of outputting a laser beam having a spectrum that includes at least three wavelength peaks, a multi-wavelength oscillation control mechanism capable of controlling energy of each of the wavelength peaks, a spectrum detecting unit that detects the spectrum of the above-mentioned laser beam, and a controller that controls the multi-wavelength oscillation control mechanism based on a detection result detected by the spectrum detecting unit.

Abstract: Semiconductor laser diodes, particularly broad area single emitter (BASE) laser diodes of high light output powers are commonly used in opto-electronics. Light output power and stability of such laser diodes are of crucial interest and any degradation during normal use is a significant disadvantage. The present invention concerns an improved design of such laser diodes, the improvement in particular significantly minimizing or avoiding (front) end section degradation at very high light output powers by controlling the current flow in the laser diode in a defined way. This is achieved by controlling the carrier injection, i.e. the injection current, into the laser diode in a novel way by creating single current injection points along the laser diode's longitudinal extension, e.g. along the waveguide. Further, the supply current/voltage of each single or group of current injection point(s) may be separately regulated, further enhancing controllability of the carrier injection.

Abstract: There is provided a driving method of a self-oscillating semiconductor laser device including a first compound semiconductor layer having a first conductive type and composed of a GaN base compound semiconductor, a third compound semiconductor layer and a second compound semiconductor layer configuring an emission region and a saturable absorption region, are successively laminated, a second electrode formed on the second compound semiconductor layer, and a first electrode electrically connected to the first compound semiconductor layer. The second electrode is separated into a first portion to create a forward bias state by passing current to the first electrode via the emission region and a second portion to apply an electric field to the saturable absorption region by a separation groove. The current greater than a current value where kink is occurred in optical output-current characteristics is to be passed to the first portion of the second electrode.

Abstract: A surface emitting semiconductor laser includes a substrate; a first semiconductor distributed bragg reflector of a first conductive type; an active region; a second semiconductor distributed bragg reflector of a second conductive type; a current confinement layer that confines current in the active region; an optical confinement layer that confines light in the active region; and an optical loss unit including center and periphery portions in a predetermined direction, and gives a larger optical loss to the periphery portion than that of the center portion. Also, Do1<Do2 and Dn<Do2 are satisfied, where Do1 is a width of an optical confinement region of the optical confinement layer in the predetermined direction, Do2 is a width of a current confinement region of the current confinement layer in the predetermined direction, and Dn is a width of the center portion of the optical loss unit in the predetermined direction.

Abstract: A laser diode includes: a plurality of strip-shaped laser structures arranged in parallel with each other, and including a lower cladding layer, an active layer, and an upper cladding layer in this order; a plurality of strip-shaped upper electrodes singly formed on a top face of the respective laser structures, and being electrically connected to the upper cladding layer; a plurality of wiring layers being at least singly and electrically connected to one of the respective upper electrodes; and a plurality of pad electrodes formed in a region different from that of the plurality of laser structures, and being electrically connected to one of the respective upper electrodes with the wiring layer in between. The respective wiring layers have an end in a region different from a region where the respective wiring layers are contacted with the upper electrode.

Abstract: A method for producing light emission from a two terminal semiconductor device with improved efficiency, includes the following steps: providing a layered semiconductor structure including a semiconductor drain region comprising at least one drain layer, a semiconductor base region disposed on the drain region and including at least one base layer, and a semiconductor emitter region disposed on a portion of the base region and comprising an emitter mesa that includes at least one emitter layer; providing, in the base region, at least one region exhibiting quantum size effects; providing a base/drain electrode having a first portion on an exposed surface of the base region and a further portion coupled with the drain region, and providing an emitter electrode on the surface of the emitter region; applying signals with respect to the base/drain and emitter electrodes to obtain light emission from the base region; and configuring the base/drain and emitter electrodes for substantial uniformity of voltage distrib

Abstract: This semiconductor laser apparatus includes a base, a plurality of electrodes arranged along a first direction on an upper surface of the base, a plurality of semiconductor laser devices bonded to respective upper surfaces of the plurality of electrodes, emitting laser beams in a second direction, and a photodetector having a photosensitive surface arranged in a region of the base in a third direction relative to the plurality of semiconductor laser devices. An electrode arranged in a position other than end portions in the first direction and a fourth direction, of the plurality of electrodes has an extraction wiring portion arranged on the photosensitive surface of the photodetector.

Abstract: A method and device for emitting electromagnetic radiation at high power using nonpolar or semipolar gallium containing substrates such as GaN, AN, InN, InGaN, AlGaN, and AlInGaN, is provided. In various embodiments, the laser device includes plural laser emitters emitting green or blue laser light, integrated a substrate.

Abstract: An emitting device includes a first electrode on a base substrate, a second electrode on the base substrate, a third electrode on the base substrate, an emitting structure on and/or at a same level as the first electrode, a first pattern on the base substrate being electrically connected to the first electrode, and a plurality of second patterns on the base substrate, wherein at least one of the second patterns is arranged on a first side of the first pattern and is electrically connected to the second electrode and at least another one of the second patterns is arranged on a second side of the first pattern and is electrically connected to the third electrode, the first side opposing the second side.

Abstract: A method for producing a high frequency optical signal component representative of a high frequency electrical input signal component, includes the following steps: providing a semiconductor transistor structure that includes a base region of a first semiconductor type between semiconductor emitter and collector regions of a second semiconductor type; providing, in the base region, at least one region exhibiting quantum size effects; providing emitter, base, and collector electrodes respectively coupled with the emitter, base, and collector regions; applying electrical signals, including the high frequency electrical signal component, with respect to the emitter, base, and collector electrodes to produce output spontaneous light emission from the base region, aided by the quantum size region, the output spontaneous light emission including the high frequency optical signal component representative of the high frequency electrical signal component; providing an optical cavity for the light emission in the regi

Abstract: A nitride semiconductor laser device is formed by growing a group III nitride semiconductor multilayer structure on a substrate. The group III nitride semiconductor multilayer structure has a laser resonator including an n-type semiconductor layer, a p-type semiconductor layer and a light emitting layer held between the n-type semiconductor layer and the p-type semiconductor layer. The laser resonator is arranged to be offset from the center with respect to a device width direction orthogonal to a resonator direction toward one side edge of the device. A wire bonding region having a width of not less than twice the diameter of an electrode wire to be bonded to the device is formed between the laser resonator and the other side edge of the device.

Abstract: A CO2 gas discharge laser includes a housing enclosing spaced-apart electrodes and a lasing gas. A laser resonator extends between the spaced-apart electrodes. An RF power supply provides RF power for creating a discharge in the lasing gas, causing laser radiation to be delivered by the laser resonator. The power of the output radiation is directly dependent on the RF power provided to the electrodes and inversely dependent of the temperature of the gas discharge. A signal representative of the discharge-temperature is used to adjust the RF power supplied to the electrodes such that the power of the output radiation is about constant.

Abstract: A vertical cavity surface emitting laser capable of reducing parasitic capacitance while suppressing power consumption, and a method of manufacturing thereof are provided. The vertical cavity surface emitting laser includes a columnar mesa including, on a substrate, a first multilayer reflector, an active layer, and a second multilayer reflector in order from the substrate side, and also including a current narrowing layer. The columnar portion of the mesa including the active layer and the current narrowing layer is formed within a region opposed to the first multilayer reflector and a region opposed to the second multilayer reflector, and a cross section area of the columnar portion is smaller than a cross section area of the second multilayer reflector.

Abstract: The present invention provides a semiconductor device realizing improved adhesion between a low-dielectric-constant material and a semiconductor material. The semiconductor device includes, on a semiconductor layer, an adhesion layer and a low-dielectric-constant material layer in order from the semiconductor layer side. The adhesion layer has a projection/recess structure, and the low-dielectric-constant material layer is formed so as to bury gaps in the projection/recess structure.

Abstract: A cut-out portion of a ground conductor is located in a region where a header faces a flexible board from the junction of a signal pin and a signal line and faces the signal line. The size of the cut-out portion is determined so that the impedance of the signal pin is matched to the impedance of the signal line.

Abstract: A light source device for a display device for projecting an image on a screen is provided, the light source device for display device including a light source unit operable to output light; an image outputting unit operable to output an image by giving an image signal to the light; and a control circuit operable to switch the image output from the image outputting unit between a normal image and a mirror reversed image formed by reversing the normal image right and left by controlling the image signal, such that outputting type is switched between a front projection in which the image is projected onto the screen from a front on the same side as the viewing side, and a rear projection in which the image is projected onto the screen from a rear plane on the opposite side to the viewing side.

Abstract: One objective of the present invention is to provide a laser device which is capable of scanning beams of a laser light of high output power at a high speed without using mechanical scanning mechanisms. A plurality of the upper electrodes 33 is linearly arranged in the photonic crystal laser provided with an active layer 21 and a two-dimensional photonic crystal layer 23 which are held between upper electrodes 33 and a lower electrode 27. A current is introduced from one upper electrode 33 or the plurality of the upper electrodes 33 disposed adjacently. Therefore, the active layer 21 generates light and the light is intensified by diffraction in the two-dimensional photonic crystal layer 23, so that a stronger laser light is emitted to the outside from around the upper electrodes 33 into which a current is introduced. When the current-injected upper electrodes are sequentially switched, a laser light scan is performed in the direction of the array of the upper electrodes.

Abstract: A semiconductor laser device includes: a laminated body including an active layer, a cladding layer provided on the active layer, and a contact layer provided on the cladding layer, the laminated body having a first and second end face forming a resonator for light emitted from the active layer; and an electrode provided on the contact layer and including an ohmic section injecting a current into the active layer and a first current adjustment section provided between one end of the ohmic section and the first end face. The ohmic section contains a metal which has a smaller work function than any metal constituting the current adjustment section.

Abstract: A gas discharge laser includes elongated discharge electrodes having an active surface width that varies along the length of the resonator. In one example each of the electrodes is formed by a row of pins having a circular active surface. The pins are diametrically aligned with the active surfaces generally coplanar.

Abstract: A semiconductor laser device and an image display device that efficiently release a heat from stripe active regions, and operated at a low-consumption current and a low-consumption electric power. A semiconductor laser element includes stripe active regions for emitting laser beams. On a base block, there are formed wirings electrically connected to stripe laser electrodes of the semiconductor laser element, respectively. The stripe laser electrodes corresponding to the stripe active regions are formed in proximity to a first surface of the semiconductor laser element, close to the active regions. An electric current is supplied to the active regions from connecting portions between each of the laser electrodes and the wirings.

Abstract: According to an aspect of the present invention, there is provided a laser diode array including: a laser array chip including: a substrate; and at least three of laser diodes that are formed on the substrate; first electrodes that are formed on each of the laser diodes so as to be isolated from one another; a sub-mount; and second electrodes that are formed on the sub-mount so as to correspond to the first electrodes and so as to be isolated from one another, wherein the laser array chip is mounted on the sub-mount through the first electrodes and the second electrodes, and wherein, among contacting surfaces between each of the first electrodes and a corresponding one of the second electrodes, a contacting area of a central one of the contacting surfaces is larger than that of an end one of the contacting surfaces.

Abstract: A semiconductor laser device has a front surface electrode formed by Au plating, a rear surface electrode formed by Au plating, an anti-adhesive film on the front surface electrode or the rear surface electrode and made of a material that does not react with Au, and a coating film that covers an end face on a light emitting side and an end face opposite the light emitting side. The anti-adhesive films may be located at least at the four corners of the front or rear surface electrode.

Abstract: An optical signal is produced from a direct modulation resonant cavity device, such as directly-modulated diode laser having an electrode divided into multiple sections. Each section is driven with an electrical waveform such that a time delay is introduced between sections so as to ensure that the different sections reach their peaks at slightly different times.

Abstract: A surface emitting laser includes an active layer disposed on a semiconductor substrate, and a pair of upper and lower electrodes for injecting carriers into the active layer. The plane surface of the lower electrode is shaped into a star so that injection of current into the active layer from the lower electrode is carried out with a high density at the center of the lower electrode and with a low density at its periphery part. In the surface emitting laser, the density distribution of the carriers injected into the active layer corresponds to the power distribution of light inside the active layer. Thereby, hole burning due to an increase in the current density in the region of the active layer corresponding to the peripheral part of the electrode is avoided, and the transverse mode stability during high output operation is significantly enhanced to improve high-output characteristic.

Abstract: A semiconductor laser source is provided wherein the wavelength selective section of the laser diode comprises a P+ type current confinement layer and first and second sets of interdigital heater electrodes formed over the current confinement layer. Individual electrode digits of the first and second sets of interdigital heater electrodes alternate in succession along a direction of optical propagation defined by the active waveguide layer of the laser diode. The first set of interdigital heater electrodes are positively or negatively biased relative to the laser diode cathode and relative to the second set of interdigital heater electrodes such that the relative bias is either less than the forward bias turn-on voltage of the P-N junction or has an absolute value less than the reverse break-down voltage of the P-N junction.

Abstract: The invention discloses an optical transmission module with digital adjustment and method thereof. The module includes a laser (21), a laser driver (22), an automatic power adjustment circuit (23), an automatic temperature adjustment circuit (24), a digital adjustment circuit (25) and a memory (26). The digital adjustment circuit, consisted of a digital-to-analog converter or a digital adjustment potentiometer, receives a digital adjustment signal and outputs, respectively, a extinction ratio adjustment signal and a cross point adjustment signal to the laser driver, an optical power adjustment signal to the automatic power adjustment circuit and an optical wavelength adjustment signal to the automatic temperature adjustment circuit. The memory stores data, using for on-line adjustment of the optical transmission module, at least including parameters of said optical transmission module and said laser emitting optical power parameters, to be reported upward.

Abstract: A line narrowed gas discharge laser system and method of operation are disclosed which may comprise: an oscillator cavity; a laser chamber comprising a chamber housing containing a lasing medium gas; at least one peaking capacitor electrically connected to the chamber housing and to a first one of a pair of electrodes; a second one of the pair of electrodes connected to an opposite terminal of the at least one peaking capacitor; a current return path connected to the chamber housing; the one terminal, the first one of the electrodes, the lasing medium gas, the second one of the electrodes, the current return path and the second terminal forming a head current inductive loop having an inductance unique to the particular head current inductive loop; a spectral quality tuning mechanism comprising a mechanism for changing the particular head current inductive loop inductance value for the particular head current inductance loop.

Abstract: An electrode structure includes a first conductive layer, an insulation layer that covers at least a portion of a marginal area of an upper surface of the first conductive layer and has a first sloped section that slopes down toward the upper surface of the first conductive layer, a first electrode having one end formed on the first conductive layer and another end formed on the first sloped section, a third electrode that is formed on the first electrode and the insulation layer, and covers the another end of the first electrode.

Abstract: A two-wavelength semiconductor laser device includes a first conductive material substrate having thereon first and second regions separated from each other. A first semiconductor laser diode is formed on the first region. A non-active layer is formed on the second region and has the same layers as those of the first semiconductor laser diode. A second semiconductor laser diode is formed on the non-active layer. A lateral conductive region is formed at least between the first and second semiconductor laser diodes.

Abstract: A fast current-controlled polarization switching VCSEL with two independent intra-cavity p-contact electrodes and two independent intra-cavity n-contact electrodes positioned along the four sides of the symmetric aperture such that there are two independent p- and n-contact pairs placed on opposite sides of the aperture in a non-overlapping configuration. The anisotropy resulting from the unidirectional current flow causes the light output to be polarized perpendicular to the direction of current flow. A VCSEL driver circuit switches the polarization state of the output light by using the two orthogonal pairs of non-overlapping intra-cavity contacted electrodes to change the direction of current flow into the VCSEL aperture by 90 degrees.

Abstract: In order to reduce the sizes of a tunable optical filter and an external-resonator-type tunable semiconductor laser device, the filter includes: a silicon substrate; a glass substrate which is disposed opposed to the face of the silicon substrate and is equipped with a transparent electrode layer provided over the face thereof disposed to the substrate; an optical diffracting-and-reflecting layer disposed over the face of the silicon substrate; and a liquid crystal layer disposed between the optical diffracting-and-reflecting layer and the transparent electrode layer; and the filter is characterized in that in the filter where the refractive index of the liquid crystal layer is controlled by the voltage applied between the silicon substrate and the transparent electrode layer, a silicon-substrate-side electrode terminal for applying the voltage thereto is provided on the backside of the silicon substrate, this filter being assembled in the external-resonator-type tunable semiconductor laser device.

Abstract: Submount substrates are connected to both sides of a laser diode via hard solders. The lower submount substrate and a heat sink are connected together by a soft solder. The heat sink and a presser electrode are fixed with a predetermined gap therebetween via an insulating spacer. A coil electrode is fitted in a V-shaped groove of the presser electrode. As the coil electrode is deformed slightly elastically, the coil electrode is pressed against the upper submount substrate.

Abstract: A fast current-controlled polarization switching VCSEL with two independent intra-cavity p-contact electrodes and two independent intra-cavity n-contact electrodes positioned along the four sides of the symmetric aperture such that there are two independent p- and n-contact pairs placed on opposite sides of the aperture in a non-overlapping configuration. The anisotropy resulting from the unidirectional current flow causes the light output to be polarized perpendicular to the direction of current flow. A VCSEL driver circuit switches the polarization state of the output light by using the two orthogonal pairs of non-overlapping intra-cavity contacted electrodes to change the direction of current flow into the VCSEL aperture by 90 degrees.

Abstract: In order to improve a pumping light source for laser-active media comprising an outer member enclosing a gas discharge medium, a first electrode acting as a cathode and having a first electrode end located within the outer member, a second electrode acting as an anode and having a second electrode end located within the outer member and a gas discharge chamber located within the outer member between the electrode ends facing one another, in such a manner that the service life thereof is longer it is suggested that the first electrode end be essentially cooled by radiation and that a predominantly diffuse gas discharge be formed proceeding from an areally extended surface area located at the first electrode end.

Abstract: A laser system includes an optically pumped laser resonator that produces a fundamental-wavelength beam. A temperature-tuned frequency converter outside the laser resonator converts a portion of the fundamental-wavelength beam to a frequency-converted beam. The frequency converter includes at least one temperature-tuned optically nonlinear crystal. The power and position of the frequency-converted beam are dependent on the temperature of the optically nonlinear crystal and the optical pumping power. The power and position of the frequency-converted beam are monitored. The temperature of the optically nonlinear crystal is adjusted to maintain the frequency-converted beam at a predetermined position. The optical pump power is adjusted to maintain the power of the frequency-converted beam at a predetermined level.

Abstract: A fast current-controlled polarization switching VCSEL with two independent intra-cavity p-contact electrodes and two independent intra-cavity n-contact electrodes positioned along the four sides of the symmetric aperture such that there are two independent p- and n-contact pairs placed on opposite sides of the aperture in a non-overlapping configuration. The anisotropy resulting from the unidirectional current flow causes the light output to be polarized perpendicular to the direction of current flow. A VCSEL driver circuit switches the polarization state of the output light by using the two orthogonal pairs of non-overlapping intra-cavity contacted electrodes to change the direction of current flow into the VCSEL aperture by 90 degrees.

Abstract: In the semiconductor laser device of the present invention, a P-type diffusion region 3A is disposed in an N? epitaxial layer 2 of a silicon submount 16, and an N-type diffusion region 4A is disposed in this P-type diffusion region 3A. The P-type diffusion region 3A and the N-type diffusion region 4A are positioned under a red laser diode 14, and the red laser diode 14 is directly connected on the N-type diffusion region 4A via electrodes 7, 8 without an insulating film. Consequently, a short circuit between the red laser diode 14 and the silicon submount 16 can be prevented. Therefore, according to this semiconductor laser device, occurrence of deterioration or failure of a semiconductor light-emitting element upon a high-temperature operation can be prevented.

Abstract: A semiconductor laser source includes a laser diode having front and rear facets. The laser diode includes a substrate and a lower cladding layer disposed on the substrate. The lower cladding layer is doped with a dopant of the first conductivity type. An active layer is disposed on the lower cladding layer and an upper cladding layer is disposed on the active layer. The upper cladding layer is doped with a dopant of the second conductivity type. At least one electrode is disposed on a first outer layer of the diode. A pair of electrodes is disposed on a second outer layer of the diode. The second outer layer is located on a side of the diode opposing the first outer layer. The pair of electrodes is configured to allow application of different currents to each one of the electrodes in the pair of electrodes. A reflector, which is located external to the laser diode, is in optical communication with the front facet of the laser diode for providing optical feedback to the active region.

Abstract: The energy distribution of the beam spot on the irradiated surface changes due to the change in the oscillation condition of the laser or before and after the maintenance. The present invention provides an optical system for forming a rectangular beam spot on an irradiated surface including a beam homogenizer for homogenizing the energy distribution of the rectangular beam spot on the irradiated surface in a direction of its long or short side. The beam homogenizer includes an optical element having a pair of reflection planes provided oppositely for reflecting the laser beam in the direction where the energy distribution is homogenized and having a curved shape in its entrance surface. The entrance surface of the optical element means a surface of the optical element where the laser beam is incident first.

Abstract: A large area slab laser, wherein disharge is confined between two large area electrodes. A two dimensional array of inductors is placed across the electrodes so that the standing wave patterns associated with the propagation of the high frequency driving current are corrected. In one embodiment, the electrodes are planar, in another, the electrodes are annular.

Abstract: An optical system for producing high power laser beams has an in/out coupler for receiving an input laser beam from an oscillator. The coupler inputs the beam to a first multiplexer which produces a plurality of beams which are sent to a plurality of fiber amplifiers. A second beam multiplexer receives the thus amplified plurality of beams to combine then into a single amplified beam which is input to a loop PCM (phase conjugate mirror). A multi-mode fiber amplifier is included in the loop PCM. The output of the loop PCM is phase conjugated with the amplified beam input to the loop PCM thereby eliminating any phase and polarization distortions and aberrations occurring in the fiber amplifiers. The output of the loop PCM is supplied in reverse direction through the second multiplexer, the fiber amplifiers and the first multiplexer in that order and then through the in/out coupler as a high power output laser beam.

Abstract: The present invention provides a novel and improved technique for achieving a combined RF-DC gas discharge in the optical cavity of the gas laser. The combination of the fast pre-ionization with the transverse RF discharge and the high power excitation with the highly-efficient longitudinal DC discharge allows for a high-speed laser gain modulation of the active medium of the high-power gas laser. At the same time, the all-metal electrode system allows for a very compact, reliable and low cost design of the gas laser.

Abstract: Cardiac laser surgery apparatus including a CO2 slab laser, and a laser delivery system for delivering laser pulses from the laser to a patient's heart.