Abstract: A semiconductor laser includes: a DBR (Distributed Bragg Reflector) region having a diffraction grating; a FP (Fabry-Perot) region having no diffraction grating; and an optical waveguide section placed between the DBR region and an outputting end surface. A length of the optical waveguide section is longer than a length of the DBR region in a resonator length direction.

Abstract: A laser array light source unit 1 includes: a plurality of semiconductor lasers 2 each including a main body portion 2a and a leg portion 2b with two leading electrodes; a laser holder 3 holding the main body portions 2a, and having through-holes for the leg portions 2b; a pressing member 5 for fixing the semiconductor lasers 2 to the laser holder 3; an insulator 4 including a plurality of electrode insertion portions 4f having through-holes for the leading electrodes; and a wiring base 6 for electrically connecting at least two of the semiconductor lasers 2 in series. The insulator 4 includes a connecting portion 4b for connecting the plurality of electrode insertion portions 4f in the same direction in which the plurality of semiconductor lasers 2 are arranged. The wiring base 6 includes first through-holes into which the leading electrodes of the semiconductor lasers 2 are inserted.

Abstract: A semiconductor device mounting structure includes: a substrate with an opening provided therein; a frame member with a frame body and a protruding portion that protrudes from the frame body, the frame body being formed and accommodated in a groove around the opening; a coreless substrate provided above the substrate and supported by the protruding portion of the frame member; and semiconductor elements provided on the coreless substrate.

Abstract: A wind tunnel with a closed section for aeroacoustic measurements with an anechoic coating including: a) a first cavity having a thickness D1 in a range of 20?D1?50 mm filled with a fibrous material with a flow resistance R in a range of 10?R?50 kRayl/m; b) a first microperforated panel having a thickness t1 in a range of 0.25?t1?0.75 mm and with a perforation percentage p1 in a range of 15%?p1?30%; c) a second air cavity having a thickness D2 in a range of 10?D2?30 mm; d) a second microperforated panel having a thickness t2 in a range of 0.25?t2?0.75 mm and with a perforation percentage p2 in a range of 15%?p2?30%. The perforations of the panels can be circular or longitudinal slot-shaped having a diameter d or width w in a range of 0.2?d, w?0.5 mm.

Abstract: According to the repetition frequency control device, a master laser outputs a master laser light pulse the repetition frequency of which is controlled to a predetermined value. A slave laser outputs a slave laser light pulse. A reference comparator compares a voltage of a reference electric signal the repetition frequency of which is the predetermined value and a predetermined voltage with each other, thereby outputting a result thereof. A measurement comparator compares a voltage based on a light intensity of the slave laser light pulse and the predetermined voltage with each other, thereby outputting a result thereof. A phase difference detector detects a phase difference between the output from the reference comparator and the output from the measurement comparator. A loop filter removes a high-frequency component of an output from the phase difference detector.

Abstract: A high-brightness laser module is configured with a beam-compression unit capable of reducing a diameter of parallel light beams which are emitted by respective spaced apart individual laser diodes. The module further has an objective lens configured to losslessly launch the light with the reduced diameter into a fiber.

Abstract: A nitride semiconductor laser device includes: a stack, the stack including an n-type layer and a p-type layer each including a nitride semiconductor; an n-electrode electrically coupled to the n-type layer; a p-electrode electrically coupled to the p-type layer; and a thermally conductive portion disposed in contact with the p-type layer in a region which is different from the region where the p-electrode is connected, wherein the thermally conductive portion is electrically insulated from the p-electrode. Manufacturing steps specific to nitride semiconductors are employed to form the device. An optical apparatus, such as an optical disc device, a display device, or a lighting device includes such a nitride laser device and depends its functions thereto.

Abstract: A surface-emitting laser array includes a plurality of surface-emitting laser elements. Each surface-emitting laser element includes a first reflection layer formed on a substrate, a resonator formed in contact with the first reflection layer and containing an active layer, and a second reflection layer formed over the first reflection layer and in contact with the resonator. The second reflection layer contains a selective oxidation layer. The first reflection layer contains on the active layer side at least a low refractive index layer having an oxidation rate equivalent to or larger than an oxidation rate of a selective oxidation layer contained in the second reflection layer. The resonator is made of an AlGaInPAs base material containing at least In. A bottom of a mesa structure is located under the selective oxidation layer and over the first reflection layer.

Abstract: In accordance with one embodiment of the present disclosure, a DBR laser diode is provided where the wavelength selective grating of the laser diode is characterized by an aperiodically shifted grating phase ? and a Bragg wavelength ?B. The aperiodically shifted grating phase ? is substantially symmetric or substantially ?-shifted symmetric relative to a midpoint CL or shifted midpoint CL* of the DBR section. The phase ? of the wavelength selective grating is characterized by aperiodic phase jumps of magnitude ?J1, J2, . . . and segment lengths l0, 1, . . . . The phase jumps of the wavelength selective grating are arranged substantially symmetrically about a midpoint CL or shifted midpoint CL* of the DBR section along the optical axis of the DBR laser diode. At least two phase jumps reside on each side of the midpoint CL or shifted midpoint CL* of the DBR section.

Abstract: Two or more lasers or other temperature sensitive optical devices can be disposed in an operating environment, for example in a common enclosure exposed to the environment. The environment can have a temperature that fluctuates, for example in connection with random events, weather, seasons, etc. Each laser's temperature can track the temperature of the environment in steps, with each laser following a distinct temperature track. The lasers can alternate outputting light into a wavelength division multiplexing channel. For example, during one timeframe, one laser can provide an optical communication signal having a wavelength complying with a wavelength division multiplexing criterion. During another timeframe, the other laser can provide an optical signal having substantially the same wavelength. Operating a laser at an elevated temperature can shorten laser lifetime.

Abstract: A semiconductor laser using an external resonator. A laser diode chip emits a laser beam in a horizontal direction parallel to the bottom plane of a package, and the travel path of the laser beam is changed into a vertical direction by a reflective mirror next to a laser beam-emitting surface of the laser diode chip. As a result, the beam arrangement of the external cavity is available on a plane parallel to the bottom plane of the package through a lens installed on the vertical travel path of the laser beam. Consequently, the beam is easily arranged. Furthermore, an additional reflective mirror is installed above the lens which changes the vertical travel path into a horizontal travel path, which allows the beam traveling parallel to the bottom plane to be easily arranged through the lens. The production of the package can also be enabled in the configuration where various optical tools are arranged on the bottom of the package.

Abstract: A laser beam combining and power scaling device and method. A first highly reflective mirror residing perpendicular to the first optical axis reflecting radiation emitted from the first laser head. A first Q-switch in alignment with the first optical axis interposed between the first highly reflective mirror and the first laser head. A second highly reflective mirror residing perpendicular to the second optical axis reflecting radiation emitted from the second laser head. The second Q-switch in alignment with the second optical axis is interposed between the second highly reflective mirror and the first laser head. A third optical axis is coincident with the first optical axis. A third highly reflective mirror residing perpendicular to the third optical axis in alignment therewith. The third optical axis may include a third diode pumped laser head and Q-switch. A beam splitter resides at the intersection of the axes.

Abstract: Loss modulated silicon evanescent lasers are disclosed. A loss-modulated semiconductor laser device in accordance with one or more embodiments of the present invention comprises a semiconductor-on-insulator (SOI) structure resident on a first substrate, the SOI structure comprising a waveguide in a semiconductor layer of the SOI structure, and a semiconductor structure bonded to the semiconductor layer of the SOI structure, wherein at least one region in the semiconductor layer of the SOI structure controls a photon lifetime in the semiconductor laser device.

Abstract: Provided is a group-III nitride semiconductor laser device with a laser cavity allowing for a low threshold current, on a semipolar surface of a support base in which the c-axis of a hexagonal group-III nitride is tilted toward the m-axis. First and second fractured faces 27, 29 to form the laser cavity intersect with an m-n plane. The group-III nitride semiconductor laser device 11 has a laser waveguide extending in a direction of an intersecting line between the m-n plane and the semipolar surface 17a. For this reason, it is feasible to make use of emission by a band transition enabling the low threshold current. In a laser structure 13, a first surface 13a is opposite to a second surface 13b. The first and second fractured faces 27, 29 extend from an edge 13c of the first surface 13a to an edge 13d of the second surface 13b. The fractured faces are not formed by dry etching and are different from conventionally-employed cleaved facets such as c-planes, m-planes, or a-planes.

Abstract: The present invention enables simultaneous setting or automatic setting of a pulse peak and a pulse width of a light pulse. In a configuration comprising a light emitting element outputting laser light, a driving current supply section supplying a driving current to the light emitting element, a modulator applying a modulation voltage for pulse modulation of the laser light to the light emitting element, and a modulation control section controlling a modulation pattern as a pattern of pulse modulation of the modulation voltage for the modulator, the modulation control section sets a modulation voltage value in the modulation pattern based on information on a driving current value, and sends information on the modulation pattern to the modulator so that the modulation voltage reaches the set value.

Abstract: The invention relates to an apparatus and a method for referencing an optical frequency of a tunable laser. Light from a reference laser and the tunable laser is injected into a length of an optical waveguide from opposite ends thereof. When the optical frequency of the tunable laser is swept, SBS induced positive and negative peaks in the optical power of light transmitted through the waveguide are used to provide an accurate frequency change reference.

Abstract: A multi-wavelength semiconductor laser device includes a block having a rectangular groove with a bottom face and two side faces extending in a predetermined direction; and laser diodes with different light emission wavelengths mounted on the bottom face and the side faces of the groove in the block so that their laser beams are emitted in the predetermined direction.

Abstract: A laser assembly comprises a substrate, one or more standoffs and a semiconductor laser. The substrate has a first doped region and a second doped region. The second doped region is proximate to an upper surface of the substrate and forms a pn junction with the first doped region. The semiconductor laser is operative to emit light from an upper surface and a lower surface. Moreover, the semiconductor laser is attached to the upper surface of the substrate with the one or more standoffs such that the light emitted from the lower surface of the semiconductor laser impinges on the second doped region.

Abstract: In order to maintain a constant laser output pulse power in a RF-energized, sealed-off, diffusion cooled, pulsed, CO2 gas-discharge laser, each laser output pulse is generated by train or burst of shorter RF pulses. When the time between laser output pulses becomes short enough that the power in one pulse would be reduced by gas-discharge heating effects of a previous pulse, power in the RF pulse trains is varied by varying the duration or duty cycle of pulses in the bursts, thereby keeping output-pulse power in the laser output pulses constant. RF pulses in any burst can have a different duration for tailoring the temporal shape of a corresponding laser-output pulse.

Abstract: Methods and systems for split voltage domain transmitter circuits are disclosed and may include amplifying a received signal in a plurality of partial voltage domains. Each of the partial voltage domains may be offset by a DC voltage from the other partial voltage domains. A sum of the plurality of partial domains may be equal to a supply voltage of the integrated circuit. A series of diodes may be driven in differential mode via the amplified signals. An optical signal may be modulated via the diodes, which may be integrated in a Mach-Zehnder or a ring modulator. The amplified signals may be communicated to the diodes, connected in a distributed configuration, via even-mode coupled transmission lines. The partial voltage domains may be generated via stacked source follower or emitter follower circuits. The voltage domain boundary value may be at one half the supply voltage due to symmetric stacked circuits.