Patents by Inventor William Streifer

William Streifer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4317086
    Abstract: A passivation layer of perylene and its incorporation in three layer reflector structure deposited on the light emitting surface of a semiconductor electroluminescent device is disclosed. The reflector structure comprises a layer of low refractive index material, a layer of high refractive index material and a layer of low refractive index material. Preferably the index of refraction for the high refractive index layer is in excess of 3.5 and the materials for this layer may be antimony, bismuth, tellurium, selenium, germanium, arsenic, sulfur, and admixtures thereof. Admixtures may include chemically diordered crystalline or amorphous alloys of selenium, tellurium, arsenic and germanium. Examples of low index materials are Al.sub.2 O.sub.3, MgF.sub.2, SiO.sub.2, ZnO.sub.2 or perylene.
    Type: Grant
    Filed: September 13, 1979
    Date of Patent: February 23, 1982
    Assignee: Xerox Corporation
    Inventors: Donald R. Scifres, Neville Connell, William Streifer
  • Patent number: 4317085
    Abstract: A heterostructure semiconductor laser is characterized by having a channeled mesa contiguous with the top surface of the laser substrate. The channeled mesa comprises an elongated mesa with an elongated channel formed in the top surface of the mesa structure. The epitaxial growth of semiconductor layers over the channeled mesa produces layers having uniform thickness with smooth facet like texture and without layer surface irregularities. The channeled mesa may also be employed in the fabrication of nonplanar large optical cavity lasers.
    Type: Grant
    Filed: September 12, 1979
    Date of Patent: February 23, 1982
    Assignee: Xerox Corporation
    Inventors: Robert D. Burnham, Donald R. Scifres, William Streifer
  • Patent number: 4316156
    Abstract: Integrated laser diode devices are utilized as repeater elements and logic circuit elements in fiber optic and other light transfer systems. One embodiment discloses a six layer device (10) which is triggered not by an external electrical gating source, but by an external light source (8, 9) as from an optical fiber. Another embodiment operates a laser diode in a bilateral mode. That is, depending on the polarity of the applied voltage bias V to the device (50), two separate light pulses are emitted from different regions (56, 52) of the crystal. A further embodiment utilizes the semiconductor laser as a logical AND function. When the electrical bias (V) of the device (60) is set so that when at least two external light sources (67, 68) are applied, the device will emit laser light (69). Still another embodiment utilizes two semiconductor laser devices (911, 913) as an astable optical multivibrator (90).
    Type: Grant
    Filed: July 12, 1979
    Date of Patent: February 16, 1982
    Assignee: Xerox Corporation
    Inventors: Donald R. Scifres, William Streifer, Robert D. Burnham
  • Patent number: 4309670
    Abstract: Improved lateral carrier and optical confinement is achieved in heterostructure diodes and lasers having a Fabry-Perot cavity transverse to the plane of the p-n junction of the device. Structural features during fabrication improve carrier confinement to the active region in the established optical cavity. Current confinement means is also fabricated above and below the active region to concentrate the current density to the active region in the optical cavity and thereby improve the overall gain of the device. Such confinement also enhances optical confinement along the cavity. Several reflector structures are disclosed for employment at the cavity ends to provide optical feedback.
    Type: Grant
    Filed: September 13, 1979
    Date of Patent: January 5, 1982
    Assignee: Xerox Corporation
    Inventors: Robert D. Burnham, Donald R. Scifres, William Streifer
  • Patent number: 4302729
    Abstract: A solid state laser in which transverse mode control is achieved by a layer of non-uniform thickness adjacent the laser active region and longitudinal mode control is achieved by a periodic structure formed in the laser substrate. The layer of non-uniform thickness is provided by forming the layer on a channeled substrate, and the teeth of the periodic structure extend in a direction transverse to the direction of the channel.
    Type: Grant
    Filed: May 15, 1979
    Date of Patent: November 24, 1981
    Assignee: Xerox Corporation
    Inventors: Robert D. Burnham, Donald R. Scifres, William Streifer
  • Patent number: 4293826
    Abstract: A semiconductor injection laser is mounted on a silicon substrate. An optical detector is integral to the substrate and aligned at oblique angles relative to the path of the light from one of the light emitting facets of the laser. The detector may be connected to the current control circuit for the laser to provide a feedback signal which is proportional to the light deflected from the facet. The transversely disposed detector may also function to detect light from another source as part of an optical communication system. The detector may be a Schottky barrier or a p-n junction.
    Type: Grant
    Filed: April 30, 1979
    Date of Patent: October 6, 1981
    Assignee: Xerox Corporation
    Inventors: Donald R. Scifres, Robert D. Burnham, William Streifer
  • Patent number: 4280106
    Abstract: A channelled substrate diode laser in which transverse and longitudinal mode control is achieved by having the laser current profile flat over the substrate channel. A flat current profile over the substrate channel, which is achieved by having the width of the path of the pump current greater than the width of the channel, causes waveguiding to be influenced only by a fixed channel guiding factor.
    Type: Grant
    Filed: May 15, 1979
    Date of Patent: July 21, 1981
    Assignee: Xerox Corporation
    Inventors: Donald R. Scifres, Robert D. Burnham, William Streifer
  • Patent number: 4280107
    Abstract: A multilayered reflector structure deposited on the light emitting surface of a semiconductor electroluminescent device and consecutively comprising a layer of low refractive index material, a layer of intermediate refractive index material and a layer of high refractive index material. Ablative means remove and form an aperture in the outer high index layer at the region of optical radiation emission from said device whereby the level of reflectivity is highest at the center of the aperture as compared to structure regions adjacent to the aperture. In this manner, fundamental mode stabilization may be achieved. Also disclosed is a nonablated three layered reflector structure.
    Type: Grant
    Filed: August 8, 1979
    Date of Patent: July 21, 1981
    Assignee: Xerox Corporation
    Inventors: Donald R. Scifres, Fernando A. Ponce, G. A. Neville Connell, William Streifer
  • Patent number: 4280108
    Abstract: A laser array comprised of a plurality of stacked emitting or active regions which are in sufficiently close contact to each other that light from each active region is coupled to the light from the adjacent active regions to form a phase-locked laser array with low composite beam divergence perpendicular to the plane of the rectifying junction of the active regions.
    Type: Grant
    Filed: July 12, 1979
    Date of Patent: July 21, 1981
    Assignee: Xerox Corporation
    Inventors: Donald R. Scifres, Robert D. Burnham, William Streifer
  • Patent number: 4277762
    Abstract: Mode control both for longitudinal and fundamental transverse modes can be achieved by employing a mesa structure on the laser substrate during fabrication. The mesa will provide significant variations in the thickness of one or more hetrostructure waveguiding layers that may be fabricated on the mesa formed substrate. As a result, the equivalent index of refraction for each waveguiding layer will be different. For longitudinal mode operation, a branching directional coupler can be directly fabricated during preferential LPE growth due to the presence of the mesa formed on the substrate. For fundamental transverse mode operation, oscillation can be restricted to a high gain region in a waveguiding layer due to the presence of the mesa and thickness variation and curvature in the active layer. Connected or juxtaposed stripe contact geometry can also be employed to provide a multicavity effect in a light waveguiding layer to enhance longitudinal mode selectivity.
    Type: Grant
    Filed: July 27, 1979
    Date of Patent: July 7, 1981
    Assignee: Xerox Corporation
    Inventors: Donald R. Scifres, William Streifer, Robert D. Burnham
  • Patent number: 4255717
    Abstract: A monolithic laser device produces a plurality of spatially displaced emitting cavities in an active layer of a semiconductor body acting as a waveguide for light wave propagation under lasing conditions. Various means are disclosed to deflect and directly couple a portion of the optical wave propagation into one or more different spatially displaced emitting cavities to improve coherence and reduce beam divergence.
    Type: Grant
    Filed: October 30, 1978
    Date of Patent: March 10, 1981
    Assignee: Xerox Corporation
    Inventors: Donald R. Scifres, William Streifer, Robert D. Burnham
  • Patent number: 4251780
    Abstract: An injection laser of the multilayer planar type, such as, heterostructure GaAs:GaAlAs lasers are provided with offset geometry in the configuration of the stripe on surface of the device to stabilize the propagating optical beam such that the power output versus current pumping characteristic is linear over an extended range of operating currents. Many types of stripe offset geometries are disclosed which contribute in various degrees to such transverse mode stabilization.
    Type: Grant
    Filed: July 3, 1978
    Date of Patent: February 17, 1981
    Assignee: Xerox Corporation
    Inventors: Donald R. Scifres, Robert D. Burnham, William Streifer
  • Patent number: 4219785
    Abstract: A light beam scanner of the moving interference fringe pattern type which includes a body of semiconductor material having a source of coherent radiation and wave guides for guiding the coherent radiation along a plurality of spatially displaced paths which are optically uncoupled, and means associated with the spatially displaced paths for producing relative phase changes between radiation in the different paths whereby interference fringes in the far field are spatially scanned. In addition, wavelength modulation of the laser over a range of about 80 A can be achieved. The source of the coherent radiation can be a single laser or a plurality of optically coupled lasers, and the optical uncoupling can be achieved by spatial displacement of the paths or by insertion of a high loss medium between the paths.
    Type: Grant
    Filed: June 26, 1978
    Date of Patent: August 26, 1980
    Assignee: Xerox Corporation
    Inventors: Donald R. Scifres, Robert D. Burnham, William Streifer
  • Patent number: 4217561
    Abstract: A laser beam scanner in which a single-lobe propogates radiation pattern through an electrically variable asymmetric electrical charge distribution. Because the electrical charge distribution determines the real and imaginary parts of the refractive index of the material through which the radiation pattern propogates the radiation pattern may be deflected by changing the charge distribution profile.
    Type: Grant
    Filed: June 26, 1978
    Date of Patent: August 12, 1980
    Assignee: Xerox Corporation
    Inventors: Donald R. Scifres, Robert D. Burnham, William Streifer
  • Patent number: 4185256
    Abstract: Mode control both for longitudinal and fundamental transverse modes can be achieved by employing a mesa structure on the laser substrate during fabrication. The mesa will provide significant variations in the thickness of one or more heterostructure waveguiding layers that may be fabricated on the mesa formed substrate. As a result, the equivalent index of refraction for each waveguiding layer will be different. For longitudinal mode operation, a branching directional coupler can be directly fabricated during preferential LPE growth due to the presence of the mesa formed on the substrate. For fundamental transverse mode operation, oscillation can be restricted to a high gain region in a waveguiding layer due to the presence of the mesa and thickness variation and curvature in the active layer. Connected or juxtaposed stripe contact geometry can also be employed to provide a multicavity effect in a light waveguiding layer to enhance longitudinal mode selectivity.
    Type: Grant
    Filed: January 13, 1978
    Date of Patent: January 22, 1980
    Assignee: Xerox Corporation
    Inventors: Donald R. Scifres, William Streifer, Robert D. Burnham
  • Patent number: 4132960
    Abstract: A heterojunction laser in which single longitudinal mode operation is achieved by heavily doping the active region of the laser. The dopent density should be approximately 10.sup.19 /cm.sup.3 when the dopent is zinc. A doping density as heavy as possible should be used when the dopent is germanium or any other acceptor impurity. The heavy doping density of the active region excludes the injection of holes into the active region and that exclusion results in single longitudinal mode operation.
    Type: Grant
    Filed: March 28, 1977
    Date of Patent: January 2, 1979
    Assignee: Xerox Corporation
    Inventors: William Streifer, Donald R. Scifres, Robert D. Burnham
  • Patent number: 4111521
    Abstract: A semiconductor device which utilizes interferometric principles and electrical control to provide either light reflection or light transmission or partial light reflection/transmission. In a preferred embodiment, the device includes an input waveguide which divides into branch waveguides, with the branch waveguides being reunited at an output waveguide. When the optical path lengths of the branched waveguides varies by an integer multiple of the light wavelength in the guides, the light waves interfere constructively at the output waveguide causing light to be transmitted into the output waveguide. When the light wave in one branch waveguide undergoes a single pass phase shift of 180.degree. relative to the light wave in the other branch waveguide, the light waves interfere at the output waveguide and are caused to return to the input waveguide through the branch waveguides. The returning light wave in the one branch waveguide once again experiences a single pass 180.degree.
    Type: Grant
    Filed: January 21, 1977
    Date of Patent: September 5, 1978
    Assignee: Xerox Corporation
    Inventors: William Streifer, Donald R. Scifres, Robert D. Burnham
  • Patent number: 4112389
    Abstract: A diode laser having an active region which has a section in the shape of a closed loop or ring, with the path length of the loop or ring causing a light wave traveling completely around the loop or ring section from a coupler section of the active region to undergo a phase shift of 180.degree. relative to its starting phase whereby the two waves interfere destructively, and thus provide optical feedback.
    Type: Grant
    Filed: January 21, 1977
    Date of Patent: September 5, 1978
    Assignee: Xerox Corporation
    Inventors: William Streifer, Donald R. Scifres, Robert D. Burnham
  • Patent number: 4077019
    Abstract: A heterojunction diode laser which achieves transverse mode control by providing adjacent to the active region layer of the laser a layer having a thickness substantially less than the thickness of the active region layer and of a material having a bandgap higher than the bandgap of the material of the active region layer. All transverse modes have increased penetration into a lossy substrate via the thin layer with the loss being least for the lowest order mode such that only the lowest order mode can be made to lase at low pumping current levels.
    Type: Grant
    Filed: January 5, 1976
    Date of Patent: February 28, 1978
    Assignee: Xerox Corporation
    Inventors: William Streifer, Donald R. Scifres, Robert D. Burnham
  • Patent number: 4063189
    Abstract: A heterojunction diode laser which utilizes leaky wave coupling through a thin confining layer or a pair of thin confining layers to produce a high powered, highly collimated output beam with high external differential quantum efficiency, and relative freedom from facet damage resulting from high optical density.
    Type: Grant
    Filed: April 8, 1976
    Date of Patent: December 13, 1977
    Assignee: Xerox Corporation
    Inventors: Donald R. Scifres, Robert D. Burnham, William Streifer