Abstract: A VCSEL having a current confinement structure comprised of deep traps formed by implanting either iron (Fe) or chrome (Cr) into a group III-V compound, such as InP or GaAs. Beneficially, the VCSEL is part of an array of VCSELs produced on a common substrate.
Abstract: An actuator for continuously aligning the primary mirror relative to the scraper the other resonator mirrors and the feedback mirror in a high power laser resonator, comprised of extended portions of the resonators primary mirror, feedback mirror and scraper mirror for a low power laser beam to travel parallel to but offset from the high power laser beam for aligning the mirrors. The low power laser beam is used to measure the position of the mirrors in the resonator. The low power beam is split into a beam which is incident on a quadrant cell for measuring the tip and tilt of the feedback mirror relative to the primary mirror and a beam which measures the translation of the feedback mirror relative to the primary mirror. A controller receives the data form the quadrant cells and sends signals to actuators on one mirror to move it relative to the other thus keeping the mirrors in constant alignment.
Abstract: An oxide-confined vertical cavity surface emitting laser having reduced parasitic capacitance. The VCSEL includes a substrate having a first mirror stack grown epitaxially thereon. The first mirror stack includes a plurality of semiconductor layers and is doped with a first doping type. An active region is grown epitaxially above the first mirror stack for generating a lasing emission. A control layer is grown epitaxially above the first mirror stack, between first mirror stack and the active region or above the active region, and includes a central non-oxidized conducting portion and an outer, laterally oxidized insulating portion. A second mirror stack is grown epitaxially above the active region and the control layer. The second mirror stack includes a second plurality of semiconductor layers doped with a second doping type. The second plurality of semiconductors layers includes pairs of high index and low index materials.
Abstract: A nitride-contained semiconductor laser element includes a layer formed of an Alx1Ga1−x1N (0.08≦x1≦0.2) lower clad layer, an active layer formed of an alternate multilayer structure including an InwGa1−wN well layer and an InvGa1−vN barrier layer, and an Alx2Ga1−x2N (0.08≦x2≦0.2) upper clad layer layered in this order on a substrate, one or a plurality of InzGa1−zN (0≦z≦0.2) buffer layer(s) of 200 nm or less in thickness being disposed in the lower clad layer and/or the upper clad layer.
Abstract: A distributed Bragg reflector laser is fabricated wherein material defects are produced in the laser's tuning waveguide region. The defects may be created by introducing impurities into the region. The defects increase the non-radiative recombination rate of injected carriers, thereby decreasing FM efficiency and improving RF performance. Injected carrier electrons are substantially separated from injected carrier holes to reduce bimolecular and Auger recombination rates, thus improving tuning range.
Abstract: A surface emitting semiconductor laser that is easy to manufacture and has a high-intensity fundamental lateral mode optical output power. The surface emitting semiconductor laser has a semiconductor substrate on which are sequentially laminated a lower n-type DBR layer, an active layer region, an upper p-type DBR layer, a p-side electrode that is an upper layer of the upper n-type DBR layer and functions as an upper electrode provided with an aperture that forms an emission region for a laser beam, and a current confinement portion formed by oxidization. On the basis of the reflectance of a cavity in a region corresponding to the p-side electrode, a metal aperture diameter (Wmetal) of the aperture and a diameter (Woxide) of the current confinement portion are determined such that the difference between an optical loss of a cavity in a higher-order lateral mode of a laser beam and an optical loss of a cavity in a fundamental lateral mode of a laser beam becomes larger.
Abstract: A light source (27) comprises a header (30), electrical conductors (31), (32), (33), a light sensor (40), a laser (39), a can (28), a convex lens (36), and an external control circuit (34). A window (35) is defined in an inclined top of the can (28), and the convex lens (36) is mounted within the window (35). A convex surface of the inclined convex lens (36) faces away from the light sensor (40). The laser (39) and the light sensor (40) are separately mounted on the header (30). The electrical conductors (31), (32), (33) electrically connect with the control circuit (34). The convex lens (36) has a pre-determined curvature such that emitted light beams of the laser (39) reflected from the lens (36) converge onto the light sensor (40). Accordingly, the reflected light beams (52) received by the light sensor (40) are accurately proportional to the emitted light power of the laser (39).
Abstract: A system and method for laser light amplification provides amplification of a laser light beam emitted from a laser light source as low-amplification seed laser light signal. The low-amplification seed laser light signal is transmitted to an amplification component. The amplification component amplifies the low-amplification seed laser light signal by stimulating emissions of the population inversion provided by a pumping diode to generate an amplified laser light signal. The system and method further directs the amplified laser light signal to an output destination. The result of the present invention is a system and method of operation providing higher pulse rates, improved pointing stability, and optionally variable pulse rates for a variety of uses, including for non-destructive laser ultrasonic testing of materials.
Abstract: The invention is directed to a system and a method for controllably broadening the spectral characteristics, such as the emission linewidth, of a semiconductor laser by discharging an electric pulse, for example, a charged transmission line, across the laser terminals. The linewidth-broadened lasers find application in fiber optic sensors, such as fiber optic gyroscopes and current sensors, which have a relatively short de-coherence length.
Abstract: The optical component designed preferably for use in a laser cavity for the generation of a pulsed laser beam, especially a mode-coupled beam in the microsecond to the femtosecond range, contains a coating ensemble that acts as a saturable absorber, contains several layers, and is wave-coupled and “etalon-free,” having at least one saturable absorptive layer. The sequence of layers in the coating ensemble can be laid out such that for an incident cavity beam a negative dispersion of the group velocity (negative group delay dispersion and negative group velocity dispersion) also results. In the optical component which acts among other things as a saturable absorber and can be used as such, separate, individual, discrete optical elements need not be assembled in a sandwich-type construction with minimization.
Abstract: An EL element and a laser luminescent element capable of emitting ultraviolet ray with high wave length purity. The ultraviolet electroluminescent element characterized in that: a thin film made from one of polymer and oligomer in which elements selected from Si, Ge, Sn, and Pb are directly bonded; the elements are selected from those that are the same with each other and those that are different from each other; the film is disposed between two electrodes; and at least one of the electrodes is transparent. The laser luminescent element characterized in that: a thin film made from one of polymer and oligomer in which elements selected from Si, Ge, Sn, and Pb are directly bonded is disposed between two electrodes; and the elements are selected from those that are the same with each other and those that are different from each other.
November 16, 2000
Date of Patent:
September 24, 2002
The Institute of Physical & Chemical Research
Abstract: A semiconductor laser drive control circuit includes a first hold/output unit which holds a maximum emission voltage of a semiconductor laser, and supplies the emission voltage, held by the first hold/output unit, to the semiconductor laser when an emission command signal is set. A second hold/output unit sets a bias current in the semiconductor laser, and supplies a bias voltage, held by the second hold/output unit, to the semiconductor laser when the emission command signal is reset. Also disclosed is an image forming system including N semiconductor lasers where N is an integer larger than or equal to 2, and a semiconductor laser drive control circuit which controls a laser beam emission of each of the N semiconductor lasers.
Abstract: A method is provided for fabricating microelectromechanically tunable vertical-cavity surface-emitting lasers and microelectromechanically tunable Fabry-Perot filters with precise lateral and vertical dimensional control. Strained reflective dielectric film(s) are applied to a multiple quantum well structure to electronically band-gap-engineer the quantum wells. Appropriate strain in the reflective dielectric film layers is also used to create appropriate curvature in one of the reflective dielectric film stacks so as to form a confocal cavity between a planar reflective dielectric film layer and the curved reflective dielectric film layer in the vertical cavity surface emitting laser or filter. Laser and filter structures are also provided which include a suspended membrane structure made of a dielectric/metal membrane or metal film that supports a cavity-tuning reflective dielectric film stack while being anchored at the perimeter by metal support post(s).
Abstract: Semiconductor laser chip, whereby a laser-active semiconductor structure is arranged in an optical resonator. Two or more series-connected, laser-active pn-junctions whose forward directions are isodirected are introduced into one and the same resonator of the semiconductor laser chip. A respective pn-junction whose forward direction is opposite the forward direction of the laser-active pn-junctions is arranged between two laser-active pn-junctions.
Abstract: The semiconductor laser device has a stripe optical waveguide formed in its resonator structure. The stripe optical structure has right and left sides, which are different in shape from each other in its cross sectional view at a plane vertical to the substrate and parallel to the facets of the resonator structure. In addition, at least one of the right and left sides has concave and convex portions in the longitudinal direction in the top view thereof.
The laser device can thus obtain high output characteristics stably without losing the fundamental characteristics, thereby solving the problems related to the instability of the laser light in the fundamental traverse-mode and obtaining an excellent linearity to correspond to a pulse current. Consequently, the semiconductor laser device is applicable as a light source for a highly practical optical information processing system having a fast responsibility to the pulse current waveform from the driving power supply of an optical disk drive unit.
Abstract: A structure and method for an asymmetric waveguide nitride laser diode without need of a p-type waveguide is disclosed. The need for a high aluminum tunnel barrier layer in the laser is avoided.
April 9, 1999
Date of Patent:
August 6, 2002
Christian G. Van de Walle, David P. Bour, Michael A. Kneissl, Linda T. Romano
Abstract: Laser modules that are operated intermittently are prone to stop operating after only a few thousand cycles or less. The laser modules sometimes experience a significant increase in operating temperature before they stop operating and, in some cases, manifest an opening of the electrical circuit that connects the laser diodes in the stack of laser subassemblies. In extreme cases, the laser module disintegrates into component subassemblies. These problems arise from structural failures in affixing agents like solder that are used to affix component parts to each other. The structural failures are caused by cyclical thermal expansion and contraction of component parts that exceed the elastic limit of the solder.
December 4, 1998
Date of Patent:
July 23, 2002
JDS Uniphase Corporation
John G. Endriz, Jose Chan, Edmund L. Wolak, G. Rainer Dohle
Abstract: An integrated optically pumped vertical cavity surface emitting laser (VCSEL) is formed by integrating an electrically pumped in-plane semiconductor laser and a vertical cavity surface emitting laser together with a beam steering element formed with the in-plane semiconductor laser. The in-plane semiconductor laser can be a number of different types of in-plane lasers including an edge emitting laser, an in-plane surface emitting laser, or a folded cavity surface emitting laser. The in-plane semiconductor laser optically pumps the VCSEL to cause it to lase. The in-plane semiconductor laser is designed to emit photons of relatively short wavelengths while the VCSEL is designed to emit photons of relatively long wavelengths. The in-plane semiconductor laser and the VCSEL can be coupled together in a number of ways including atomic bonding, wafer bonding, metal bonding, epoxy glue or other well know semiconductor bonding techniques. The beam steering element can be an optical grating or a mirrored surface.
Abstract: A laser marking apparatus has a number of individual laser devices (1) mounted at angles to one another. The output ends (2) of the laser devices are disposed closely adjacent to one another and a number of laser beam redirectors (5) are disposed to intercept the laser beams (3) emitted from the laser output ends (2) so as to extend the length of the laser beam paths and to decrease the angle between said laser beams (3).
Abstract: A semiconductor laser comprises: a first cladding layer of a first conduction type; an active layer stacked on the first cladding layer; and a second cladding layer of a second conduction type stacked on the active layer. The first cladding layer, the active layer and the second cladding layer are made of II-VI compound semiconductors. Pulse oscillation occurs with characteristics of a threshold current Ith(A), a threshold voltage Vth(V) of the diode composed of the first cladding layer, the active layer and the second cladding layer, a differential resistance RS(&OHgr;) of the diode after the rising, a thermal resistance Rt(K/W) and a characteristic temperature To(K). When two amounts &agr; and &bgr; are defined by:
the point (&agr;,&bgr;) exists in an area on the &agr;-&bgr; plane surrounded by the straight line &agr;=0, the straight line &bgr;=0, and the curve ((21n t−1)/t, (1−ln t)/t2) having t as a parameter.