Patents Represented by Attorney, Agent or Law Firm Michael J. Urbano
  • Patent number: 4786839
    Abstract: The target of a color CRT includes a plurality of color stripe triads which are oriented on a (111) surface parallel to the <112> crystallographic direction. The pattern of the stripe triads is etched using a SiO.sub.2 etch mask deposited directly on the YAG and an etchant comprising a hot mixture of sulfuric and phosphoric acids.
    Type: Grant
    Filed: October 11, 1985
    Date of Patent: November 22, 1988
    Assignee: American Telephone and Telegraph Company AT&T Bell Laboratories
    Inventors: Tien-Wen Hou, Tai-Chan D. Huo
  • Patent number: 4776674
    Abstract: High-tilt (e.g., 5.degree.-85.degree.) can be achieved by chemical treatment of the interior surfaces of a liquid crystal device. Illustratively, the treatment entails applying a combination of surface coupling agents one of which alone would cause the LC director to make and angle .alpha..sub.1 (e.g., .alpha..sub.1 =0.degree.; homogeneous alignment) with the surface and another of which alone would yield .alpha..sub.2 (e.g., .alpha..sub.2 =90.degree., homeotropic alignment), but together they produce .alpha..sub.3 different from .alpha..sub.1 and .alpha..sub.2.
    Type: Grant
    Filed: June 25, 1986
    Date of Patent: October 11, 1988
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Robert W. Filas, Jayantilal S. Patel
  • Patent number: 4772123
    Abstract: In the assembly of a device package, an optoelectronic device, such as a light emitting diode (LED) or a photodiode, mounted on a header is aligned with a lens, such as a spherical lens, mounted in a housing by making a light beam from a microscope incident on the lens so that light reflected from the lens creates a symmetrical reference image. Light emitted by the device (LED) or reflected from the device (photodiode) forms an object image of the active area of the device. The two images are detected by a camera and are compared (real-image observation by an operator or electronic image comparison by a computer). The device on an x-y table is moved until the object image is centered with respect to the reference image. Then the position of the device within the package is fixed by epoxying, or otherwise securing, the header to the housing.
    Type: Grant
    Filed: November 24, 1986
    Date of Patent: September 20, 1988
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Raymond J. Radner
  • Patent number: 4755715
    Abstract: A phosphor for use in CRTs comprises (Y.sub.3-p-m-n R.sub.p Pr.sub.m Tb.sub.n)(Al.sub.5-q Z.sub.q)O.sub.12, where R is a lanthanide element and Z is a Group III element. One embodiment described is a single crystal of (Y.sub.3-m-n Pr.sub.m Tb.sub.n)Al.sub.5 O.sub.12 in which the trivalent Pr and Tb activators exhibit co-emission and the phosphor emits white light.
    Type: Grant
    Filed: February 28, 1986
    Date of Patent: July 5, 1988
    Assignee: American Telephone & Telegraph Company, AT&T Bell Laboratories
    Inventors: George W. Berkstresser, Joseph Shmulovich
  • Patent number: 4755867
    Abstract: A vertical, enhancement mode InP MISFET includes a conducting n-type substrate, a semi-insulating Fe-doped InP blocking layer on the substrate, a conducting layer formed in the blocking layer, a groove which extends through both the conducting layer and the blocking layer, a borosilicate dielectric layer formed on the walls of the groove, a gate electrode formed on the dielectric layer, drain electrodes formed on each side of the gate electrode, and a source electrode formed on the bottom of the substrate. When a positive gate voltage relative to the source is applied, conduction channels are formed along the sidewalls of the groove, and current flows vertically from drain to source.
    Type: Grant
    Filed: August 15, 1986
    Date of Patent: July 5, 1988
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Chu-Liang Cheng
  • Patent number: 4755016
    Abstract: A coherent lightwave transmitter includes a relatively low power, single frequency laser which provides an injection locking signal to a plurality of higher power lasers located in separate, parallel optical paths. A modulator is interposed between the single frequency laser and the higher power lasers, and the outputs of the latter are added constructively to form a high power transmitter output. Feedback control of the optical path lengths to maintain constructive interference is also described.
    Type: Grant
    Filed: November 6, 1985
    Date of Patent: July 5, 1988
    Assignee: American Telephone and Telegraph Company AT&T Bell Laboratories
    Inventors: Bernard C. DeLoach, Jr., Richard G. Smith
  • Patent number: 4730198
    Abstract: Linear arrays of optical fibers are aligned to linear arrays of optoelectronic devices (e.g., photodiodes, diode lasers or LEDs) formed on an elongated chip. The alignment procedure results in a subassembly which includes fiber segments embedded between V-groove mounting blocks and the device array chip affixed to an end face of the blocks.
    Type: Grant
    Filed: November 26, 1984
    Date of Patent: March 8, 1988
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Michael G. Brown, Stephen R. Forrest, Daniel R. Kaplan, Paul A. Kohl, Yusuke Ota, Harvey S. Trop
  • Patent number: 4707078
    Abstract: In a display device utilizing ferroelectric (e.g., chiral, smectic C material), a stabilizing electric field perpendicular to the cell surfaces forces the molecules to orient themselves in one of two states both of which are parallel to the cell surfaces. A particular state is selected by a switching electric field also oriented perpendicular to the cell surfaces. The stabilizing field has a half-cycle time shorter than the switching time of the ferroelectric material, whereas the switching field duration is longer than or equal to the switching time of the material. The invention enables the use of relatively thick (e.g., .gtoreq.2 .mu.m) ferroelectric cells.
    Type: Grant
    Filed: April 26, 1985
    Date of Patent: November 17, 1987
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: John M. Geary
  • Patent number: 4700210
    Abstract: The area of a surface-emitting LED is reduced, and hence the number of LEDs which can be obtained from a single wafer is increased, by a chip design in which the light-emitting spot is positioned asymmetrically toward one corner of the chip. Preferably, an L-shaped contact is formed on the light output surface so that light-emitting spot emerges from between the legs of the L.
    Type: Grant
    Filed: November 21, 1984
    Date of Patent: October 13, 1987
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Randolph H. Burton, Irfan Camlibel, Robert H. Saul
  • Patent number: 4695762
    Abstract: The luminescent screen of a cathode ray tube includes an array of monocrystalline or amorphous phosphor rod-like elements which are covered with a reflective coating except for one end of each element which serves as an output face. The phenomenon of the light trapping is advantageously exploited to achieve enhanced brightness. The screen is illuminated with an electron beam which has an essentially oblong cross section and which is oriented along the elongated dimension of the elements. In one embodiment the elements comprise epitaxial Lu.sub.3 Al.sub.3 Ga.sub.2 O.sub.12 :Ce on the top of a YAG substrate, and a light absorbing layer of Lu.sub.3 Al.sub.3.5 Fe.sub.1.5 O.sub.12 is formed on the bottom of the substrate. A printer utilizing such a CRT is described. Also described is a configuration in which each of the rod-like elements functions as a laser.
    Type: Grant
    Filed: June 28, 1985
    Date of Patent: September 22, 1987
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: George W. Berkstresser, Joseph Shmulovich
  • Patent number: 4695332
    Abstract: Room temperature laser action is achieved in a cathode ray tube (CRT) in which the target includes a plurality of semiconductor layers: a thin, wide bandgap buffer layer; a thicker, narrow bandgap active layer; and a much thicker wide bandgap cavity-length-adjusting layer. The light beam direction is essentially parallel to the e-beam direction and hence is scannable.
    Type: Grant
    Filed: May 28, 1985
    Date of Patent: September 22, 1987
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Eugene I. Gordon, Uri Levy
  • Patent number: 4664480
    Abstract: In a liquid crystal device one interior surface of the cell is coated with a polymer (e.g., a crystalline polymer such as PET) which, when rubbed, produces alignment of the liquid crystal molecules, and the opposite interior surface is coated with a material (e.g., an amorphous polymer, such as PMMA) which, even if rubbed, does not produce such alignment. Also described is a combination of an aligning polymer and a non-aligning, non-polymer (e.g., a silane surfactant or bare ITO). This technique is particularly useful in producing alignment of relatively thick, ferroelectric smectic liquid crystal cells.
    Type: Grant
    Filed: April 26, 1985
    Date of Patent: May 12, 1987
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: John M. Geary, Jayantilal S. Patel
  • Patent number: 4662983
    Abstract: A multiple meltback procedure is described for removing gross contaminants and thermal degradation from InP-containing surfaces. Prior to LPE growth on an InP substrate, the substrate surface is brought into contact briefly (.ltorsim.1 sec) with an essentially pure In melt and is then brought into contact with a slightly undersaturated In/P melt. A similar triple meltback procedure is described for use prior to LPE growth over a mesa (e.g., in the fabrication of buried heterostructures).
    Type: Grant
    Filed: May 3, 1985
    Date of Patent: May 5, 1987
    Assignee: American Telephone and Telegraph Company AT&T Bell Laboratories
    Inventor: Brymer H. Chin
  • Patent number: 4661961
    Abstract: In the fabrication of buried heterostructure InP/InGaAsP lasers, mask undercutting during the mesa etching step is alleviated by a combination of steps which includes the epitaxial growth of a large bandgap InGaAsP cap layer (1.05 eV.ltorsim.E.sub.g .ltorsim.1.24 eV) and the plasma deposition of a SiO.sub.2 etch masking layer. Alternatively, the cap layer may be a bilayer: an InGaAs layer or narrow bandgap InGaAsP (E.sub.g .ltorsim.1.05 eV), which has low contact resistance, and a thin InP protective layer which reduces undercutting and which is removed after LPE regrowth is complete. In both cases, etching at a low temperature with agitation has been found advantageous.
    Type: Grant
    Filed: October 22, 1985
    Date of Patent: April 28, 1987
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Ronald J. Nelson, Randall B. Wilson
  • Patent number: 4660208
    Abstract: High resistivity Fe-doped InP-based MOCVD layers are used to constrain current to flow through the active region of a variety of devices such as CSBH and DCPBH lasers.
    Type: Grant
    Filed: June 15, 1984
    Date of Patent: April 21, 1987
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Wilbur D. Johnston, Jr., Judith A. Long, Daniel P. Wilt
  • Patent number: 4645116
    Abstract: Indium is used to bond semiconductor lasers to their heat-sinks without the presence of a corrosive liquid flux. Fluxless bonding is achieved in a vacuum chamber in reducing ambients of CO or H.sub.2. Low strain bonds are achieved at bonding temperatures of approximately 180.degree.-240.degree. C. in CO and 220.degree.-230.degree. C. in H.sub.2. Void-free bonds are achieved in CO at temperatures as low as about 205.degree. C. The technique is applicable to other microelectronic chips such as LEDs, for example.
    Type: Grant
    Filed: September 5, 1984
    Date of Patent: February 24, 1987
    Assignee: AT&T Bell Laboratories
    Inventors: Gerard E. Henein, Ralph T. Hepplewhite, Bertram Schwartz
  • Patent number: 4637685
    Abstract: To achieve a high power, large area, substantially monochromatic solid-state light source, the outputs of hundreds of discrete injection lasers are combined. For the combination, each laser is butt coupled to one end of its separate large core multimode fiber. Groups of fibers are packaged in linear arrays in separate ribbon cables and the ribbon cables are stacked in a two-dimensional rectangular array. The free ends of the fibers terminate in a common plane to make available, at such plane, a high power, large area, source of light. In one embodiment, separate fibers are coupled to the two ends of each injection laser to utilize the light emitting at both facets of the laser.
    Type: Grant
    Filed: July 8, 1983
    Date of Patent: January 20, 1987
    Assignee: AT&T Bell Laboratories
    Inventor: Eugene I. Gordon
  • Patent number: 4635263
    Abstract: A portion of the pulsed output of a 3-mirror, folded, astigmatically compensated cavity of a c.w., mode-locked, color center laser is coupled into a single-mode, polarization-preserving optical fiber. Following compression of the pulses by their propagation through the fiber, the shortened pulses, which take the form of essentially solitons, are fed back into the laser cavity so as to coincide and be in phase with the pulses in the laser cavity. Through the process of stimulated emission in the color center crystal, the injected pulses force the laser itself to produce shorter pulses of essentially the same shape as the solitons. Also described are embodiments employing a mode-locked semiconductor, fiber-Raman laser, and unidirectional pulse propagation in the fiber. Two of the fiber-Raman laser embodiments have separate gain and pulse shaping sections of optical fiber joined by an optical fiber directional coupler.
    Type: Grant
    Filed: April 10, 1986
    Date of Patent: January 6, 1987
    Assignee: AT&T Bell Laboratories
    Inventor: Linn F. Mollenauer
  • Patent number: 4626739
    Abstract: In a CRT system the luminescent screen includes an ordered array of rows and columns of phosphor elements, illustratively made of single crystal material. Each element is surrounded on all sides (except the light output face) by reflective material. To enhance light extraction efficiency, the output face may be textured. An electron beam is made incident on the output face of selected ones of the elements and scans in two dimensions across the plane of the elements. Also described is an arrangement whereby the electron beam is made incident on the back surface of the elements opposite the output face.
    Type: Grant
    Filed: May 10, 1984
    Date of Patent: December 2, 1986
    Assignee: AT&T Bell Laboratories
    Inventor: Joseph Shmulovich
  • Patent number: 4620854
    Abstract: In the liquid phase epitaxy growth of Group III-V compound semiconductors using boat-slider apparatus, melt-carry-over is essentially eliminated by prebaking the metallic solvent (e.g., In shot) in the boat to form ingots and then etching the ingots in dilute nitric or hydrochloric acid prior to adding solutes (e.g., GaAs, InP, dopants). This process removes contaminants which coalesce on the ingots and cause poor wipe-off.
    Type: Grant
    Filed: October 21, 1985
    Date of Patent: November 4, 1986
    Assignee: AT&T Bell Laboratories
    Inventors: Daniel Brasen, Michael A. DiGiuseppe, Jose A. Lourenco, Subhash Mahajan