Patents Assigned to Spectra Diode Laboratories, Inc.
  • Patent number: 4862802
    Abstract: A pyrotechnic ignition method in which a semiconductor laser bar or bars containing a number of independent laser array sources deliver optical power in a specified sequence through optical fibers to a set of pyrotechnic elements in order to initiate a sequence of pyrotechnic events, such as a fireworks display, building demolition, emergency ejection sequence, satellite launch, etc. A command signal is transmitted and received, typically by a remote station from the user. The signal is decoded to generate a set of electrical signals representing addresses of individual laser arrays on the laser bar. The laser arrays are activated in the desired sequence in response to the set of electrical signals and emit laser light. This light is transmitted along optical fibers coupled to the individual laser arrays and terminating in pyrotechnic elements. The pyrotechnic elements are ignited in response to optical power received from the optical fibers, typically by direct heating of a detonator.
    Type: Grant
    Filed: July 11, 1988
    Date of Patent: September 5, 1989
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: William Streifer, Donald R. Scifres, Jerome R. Klein
  • Patent number: 4845725
    Abstract: A window laser having at least one window region with a transparent waveguide layer optically coupled to an active region generating lightwaves. The waveguide layer is characterized by a broader guided transverse mode for the lightwaves than the active region and may have a thickness which is greater than the active region, a refractive index difference with respect to cladding layers which is less than a refractive index difference between the active region and the cladding layers, or both. The waveguide layer may be coupled to the active region via a transition region characterized by a gradual change in the guide mode width of the lightwaves, such as from a tapered increase in thickness of the waveguide layer in a direction away from the active region.
    Type: Grant
    Filed: May 20, 1987
    Date of Patent: July 4, 1989
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: David F. Welch, Donald R. Scifres
  • Patent number: 4826269
    Abstract: A plurality of diode lasers is focussed onto a single region by arranging the diodes at equally spaced locations on a first arc. Each diode laser emits light in a slit-like pattern which is characterized by orthogonal axes. In a first group of cylindrical lenses, one associated with each diode laser, each lens has a refractive surface having an axis parallel to one of the emitting axes of the laser and refracts light to a focal region of defined dimensions. Each cylindrical lens is disposed along a second arc having a circular center common with the first arc. A second group of cylindrical lenses, one associated with each laser, is also disposed on a circular arc, concentric with the other arcs, but the second group has a refractive axis perpendicular to the first refractive axis. The second group of cylindrical lenses acts upon the second axis of the source image, focussing it to the common focal region. The first and second cylindrical lens groups may be combined into a toric surface within a single lens.
    Type: Grant
    Filed: October 16, 1987
    Date of Patent: May 2, 1989
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: William Streifer, Donald R. Scifres, Gary L. Harnagel
  • Patent number: 4820010
    Abstract: An optical system producing bright light output for optical pumping, communications, illumination and the like in which one or more fiberoptic waveguides receive light from one or more diode lasers or diode laser bars and transmit the light to an output end where it is focused or collimated into a bright light image. The input end of the fiberoptic waveguide may be squashed into an elongated cross section so as to guide light emitted from an elongated light source such as a diode laser bar. The waveguides are preferably arranged at the output end into a tightly packed bundle where a lens or other optical means focuses or collimates the light. The bundle has a fused output end with a taper to a smaller output diameter, thereby producing a spatially uniform high power density light output. For diode laser bars much wider than 100 microns, a plurality of waveguides may be arranged in a line to receive the light, and then stacked at the output in a less elongated configuration.
    Type: Grant
    Filed: April 12, 1988
    Date of Patent: April 11, 1989
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: Donald R. Scifres, D. Phillip Worland
  • Patent number: 4818062
    Abstract: An optical system producing bright light output for optical pumping, communications, illumination and the like in which one or more fiberoptic waveguides receive light from one or more diode lasers or diode laser bars and transmit the light to an output end where it is focused or collimated into a bright light image. The input end of the fiberoptic waveguides may be squashed into an elongated cross section so as to guide light emitted from an elongated light source such as a diode laser bar. The waveguides are preferably arranged at the output end into a tightly packed bundle where a lens or other optical means focuses or collimates the light. For diode laser bars much wider than 100 microns, a plurality of waveguides may be arranged in a line to receive the light, and then stacked at the output in a less elongated configuration. In this manner, light from many diode lasers or laser bars may be coupled through the bundle into the end of solid state laser medium.
    Type: Grant
    Filed: March 29, 1988
    Date of Patent: April 4, 1989
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: Donald R. Scifres, D. Philip Worland
  • Patent number: 4815084
    Abstract: Lasers and laser arrays having various optical elements, such as lenses, apertures, prisms, etalons and phase plates, integrated within the resonant optical cavity of the laser. The optical elements are created by introducing a lateral geometric contour in boundaries of refractive index changes thereby causing a change in shape of phase fronts of lightwaves propagating in the laser cavity in a manner analogous to optical elements. Boundaries may be defined between an active region and transparent window regions or may be formed in other layers with which lightwaves interact, such as the layers bounding the active region. Curved boundaries produce convergent or divergent lenses. Absorbing regions may bound window regions to produce apertures for lateral mode control. A periodic step shaped boundary can be used to shift the phase of lightwaves propagating in some laser array waveguides relative to lightwaves in others of the waveguides in order to cause beam emission of a desired supermode.
    Type: Grant
    Filed: May 20, 1987
    Date of Patent: March 21, 1989
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: Donald R. Scifres, William Streifer
  • Patent number: 4809288
    Abstract: A semiconductor laser array having a plurality of waveguides at least some of which are directly joined at Y-junctions. The region near the Y-junctions provides a phase boundary condition in which lightwaves propagating in adjacent waveguides are in phase. A combination of strong and weak waveguiding is provided, with strong waveguides that eliminate evanescent coupling from occuring at least in the Y-junction regions, and with weak guides near one or both end facets permitting evanescent coupling. The evanescent coupling between adjacent weak waveguides preserves the in phase relationship that was established in the Y-junction regions, resulting in a diffraction limited single lobe far field output. Alternatively, even without evanescent coupling, the modes can adjust their phases in the weak waveguides, where the propagation constant is less tightly specified by the geometry.
    Type: Grant
    Filed: March 4, 1987
    Date of Patent: February 28, 1989
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: David Welch, Donald R. Scifres, Peter Cross, William Streifer
  • Patent number: 4803691
    Abstract: A diode laser bar producing a linear array of laser beams without lateral superradiance. The laser bar has a double-heterostructure or quantum well structure. Etched channels in the substrate create lateral corrugations in the subsequently deposited layers including the active region. The corrugations alternate between offset groove and plateau regions in the lateral direction but are straight in the longitudinal light propagating direction. Any laterally propagating light is interrupted at steps, between groove and plateau regions, by deflection, scattering or transmission out of the active region. Interruption may also be achieved with a plurality of parallel etched grooves extending in the longitudinal direction. The grooves which cut through the active region present a semiconductor-air interface for reflection and/or scattering of laterally propagating light out of the active region.
    Type: Grant
    Filed: August 28, 1987
    Date of Patent: February 7, 1989
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: Donald R. Scifres, Hsing Kung, Peter Cross, Robert D. Burnham, William Streifer
  • Patent number: 4794615
    Abstract: A laser having a combination of end and side pumping so as to produce high power pulsed output with little or no delay between side pump pulses and laser output pulses, with suppressed spiking due to gain switching, and with high modulation rates. An active medium, such as a solid state laser rod, in a resonant optical cavity is pumped by a first optical pump source directing radiant energy into an end of the active medium so as to encourage or establish lasing operation in a desired transverse cavity mode, such as the TEM.sub.00 mode. A second optical pump source directs additional radiant energy into a side of the active medium so as to amplify the intensity of the laser output in the desired mode.
    Type: Grant
    Filed: June 12, 1987
    Date of Patent: December 27, 1988
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: Josef Berger, Donald R. Scifres
  • Patent number: 4763975
    Abstract: An optical system producing bright light output for optical pumping, communications, illumination and the like in which one or more fiberoptic waveguides receive light from one or more diode lasers or diode laser bars and transmit the light to an output end where it is focused or collimated into a bright light image. The input end of the fiberoptic waveguide may be squashed into an elongated cross section so as to guide light emitted from an elongated light source such as a diode laser bar. The waveguides are preferably arranged at the output end into a tightly packed bundle where a lens or other optical means focuses or collimates the light. For diode laser bars much wider than 100 microns, a plurality of waveguides may be arranged in a line to receive the light, and then stacked at the output in a less elongated configuration. In this manner, light from many diode lasers or laser bars may be coupled through the bundle into the end of solid state laser medium.
    Type: Grant
    Filed: April 28, 1987
    Date of Patent: August 16, 1988
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: Donald R. Scifres, D. Philip Worland
  • Patent number: 4751711
    Abstract: A phased array laser having a laterally asymmetric variation in the gain or coupling of lasing elements of the array for emission in a single far field lobe. The lasing elements are confined by internal waveguide structuring, periodically spaced current confinement stripes, or by a hybrid of both waveguiding and current confinement. The widths, lengths, depths, or separations of the waveguides or stripes vary laterally across the array to affect the gain or coupling of the lasing elements. Alternate embodiments introduce lateral asymmetry in the active region or other layer thicknesses, doping, mirror facet reflectivities, A1 content of the layers, heat dissipation, or thicknesses of electrical contacts. The laterally asymmetric variations may be linear or nonlinear, monotonically increase from one edge to the other edge, or may be such that the relevant parameter is greatest or least in the center of the array.
    Type: Grant
    Filed: August 16, 1985
    Date of Patent: June 14, 1988
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: David Welch, Peter Cross, Donald R. Scifres
  • Patent number: 4719634
    Abstract: A semiconductor laser array having a plurality of sets of interconnecting waveguides, each joining two optical waveguides together at respective branching junctions. The array has a plurality of semiconductor layers disposed on a substrate, at least one of the layers forming an active region for light wave generation and propagation under lasing conditions. One or more structures, such as current confining channels, a channelled substrate and variable thickness active region define a plurality of adjacent optical emitting waveguides. The waveguides are coupled together in a coupling geometry which ensures that breaks or failures in one or more branches are bypassed, thereby maintaining in-phase laser array operation.
    Type: Grant
    Filed: October 27, 1986
    Date of Patent: January 12, 1988
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: William Streifer, Peter Cross, Donald R. Scifres
  • Patent number: 4718069
    Abstract: A semiconductor laser array having a single lobe far field intensity pattern radiating normal to the laser's light emitting facet. The laser array has a plurality of semiconductor layers disposed over a substrate, at least one of the layers forming an active region for lightwave generation and propagation under lasing conditions. A plurality of adjacent spaced apart optical waveguides defined by waveguides and interconnecting waveguides directly couples lightwaves propagating in each waveguide into an adjacent waveguide. The waveguides are characterized by separations which are not equal at the light emitting facet but are selectively varied so that the sampling function has only a single central lobe. In the preferred embodiment, separations are greatest for edge located and smallest for centrally located waveguides. Interconnecting waveguides connect adjacent waveguides at respective Y-shaped junctions, the junctions being symmetric at least on the output side of the laser.
    Type: Grant
    Filed: October 27, 1986
    Date of Patent: January 5, 1988
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: William Streifer, Donald R. Scifres
  • Patent number: 4716568
    Abstract: A diode laser array assembly made from a plurality of linear diode laser array subassemblies stacked one above the other. Each subassembly is an array of individual laser beam emitters, such as a laser bar, mounted on a support plate. An electrically conductive path goes from one major surface of a support plate, through the linear laser array, to an opposite major surface of the support plate. Each subassembly is connected physically and electrically to adjacent subassemblies to form the final assembly. In one embodiment, the support plates are electrically insulating and partly coated or covered with conducting material. The plates are either rectangular with projections and directly connected, rectangular with metal plates between each other, or rectangular and connected in a staircase configuration. Alternatively, the support plates may be electrically conducting with an insulating layer and a conducting layer disposed in a sandwich configuration.
    Type: Grant
    Filed: May 1, 1986
    Date of Patent: December 29, 1987
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: Donald R. Scifres, Peter Cross, Gary L. Harnagel
  • Patent number: 4688884
    Abstract: A fiberoptic coupling system comprising a phased array semiconductor laser and a squashed multimode light transmitting fiber. The squashed input end has an oblong, preferably elliptical, or polygonal cross-section with major and minor core widths. The major width decreases toward an output end which preferably has a circular cross-section. The minor width may increase toward the output end or remain constant. This increase and decrease correspond to the characteristic laser light beam widths and divergences in planes parallel and perpendicular to an active region of the laser such that the fiber core widths are at least as large as the laser light beam widths and the fiber has input numerical apertures that cause the beam to be coupled at the divergences. This system has a light coupling efficiency of at least 70 percent.
    Type: Grant
    Filed: November 12, 1985
    Date of Patent: August 25, 1987
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: Donald R. Scifres, D. Philip Worland
  • Patent number: 4633476
    Abstract: A heterostructure semiconductor laser emitting light in a direction vertical to the horizontal active layer has one or more internal reflectors for feedback. Angled reflectors, in the form of grooves etched at an angle exceeding the angle of total internal reflection through the layers, totally internally reflect light out of the laser. One or more of the following feedback constructions are used separately or in combination to provide low threshold current and frequency selection. Insulating windows may be put on the grooves. A periodic grating on a layer adjacent the active layer provides distributed feedback. A plurality of thin dielectric layers placed next to the active layer reflect light back into the active layer. Two parallel integral feedback facets crossing vertically through the active layer act as planar mirrors.
    Type: Grant
    Filed: November 16, 1984
    Date of Patent: December 30, 1986
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: Donald R. Scifres, Gary L. Harnagel