Patents by Inventor Ralph H. Johnson

Ralph H. Johnson 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).

  • Publication number: 20140269802
    Abstract: A laser active region can include a quantum well barrier having GaPSb. The active region can include one or more quantum wells, and a quantum well barrier having GaPSb bounding each side of each of the one or more quantum wells. The quantum well barrier can be GaP1-wSbw, where w ranges from about 0.12 to about 0.25 mole fraction, and can have a thickness of from about 20 Angstroms to about 50 Angstroms. The one or more quantum wells include InGaAs or InGaAsP. Various types of lasers can have the laser active region. Such a laser can be capable of emitting light having a wavelength of about 850 nm or +/?150 nm. As an example, a vertical cavity surface-emitting laser (VCSEL) having the laser active region. The laser may also be a tunneling laser.
    Type: Application
    Filed: March 13, 2013
    Publication date: September 18, 2014
    Applicant: FINISAR CORPORATION
    Inventor: Ralph H. Johnson
  • Patent number: 8837547
    Abstract: A method for preparing a VCSEL can use MBE for: growing a first conduction region over a first mirror region; growing an active region over the first conduction region opposite of the first mirror region, including: (a) growing a quantum well barrier having In1-xGaxP(As); (b) growing an transitional layer having one or more of GaP, GaAsP, or GaAs; (c) growing a quantum well layer having In1-zGazAsyP1-y; (d) growing another transitional layer have one or more of GaP, GaAsP, or GaAs; (e) repeating processes (a) through (d) over a plurality of cycles; and (f) growing a quantum well barrier having In1-xGaxP(As); growing a second conduction region over the active region opposite of the first conduction region, wherein: x ranges from 0.77 to 0.50; y ranges from 0.7 to 1; and z ranges from 0.7 to 0.99.
    Type: Grant
    Filed: March 19, 2012
    Date of Patent: September 16, 2014
    Assignee: Finisar Corporation
    Inventors: Ralph H. Johnson, Jerome K. Wade
  • Publication number: 20140253101
    Abstract: A system and method of measuring real-time current is disclosed. The method includes calibrating a voltage measurement device. Calibrating includes measuring a real-time voltage difference between a first measurement node located proximate a first connector on a motherboard and a second measurement node located proximate a second connector on a power supply unit (PSU), the first and the second connectors coupled to provide power to the motherboard. Calibrating further includes averaging the real-time voltage difference for a plurality of measurements; computing a resistance of the coupling based at least on a long-duration averaged current from the PSU and the averaged real-time voltage difference, the resistance varying over time; and reporting the resistance of the coupling to the voltage measurement device. The method also includes measuring a real-time current of the PSU at the voltage measurement device based at least on the resistance of the coupling and the real-time voltage difference.
    Type: Application
    Filed: March 6, 2013
    Publication date: September 11, 2014
    Inventors: Shiguo Luo, Ralph H. Johnson, III, James L. Petivan, III, Hang Li
  • Patent number: 8815617
    Abstract: A semiconductor structure configured for use in a VCSEL or RCLED. The semiconductor structure includes an oxidizing layer constructed from materials that can be oxidized during a lithographic process so as to create an oxide aperture. The semiconductor structure further includes a number of layers near the oxidizing layer. A passivation material is disposed on the layers near the oxidizing layer. The passivation material is configured to inhibit oxidation of the layers.
    Type: Grant
    Filed: June 22, 2007
    Date of Patent: August 26, 2014
    Assignee: Finisar Corporation
    Inventor: Ralph H. Johnson
  • Publication number: 20140198817
    Abstract: A laser can include an active region having: one or more quantum wells having InGaAsP; and two or more quantum well barriers having GaAsP bounding the one or more quantum wells, wherein the active region is devoid of Al. The laser emits light having about 850 nm. The one or more quantum wells can have a composition InxGa1-xAs1-yPy according to Equation 1: y=0.0018567*QW+1.18*x?0.14373, where QW is the width of the quantum well in Angstroms; x is mole fraction of In; and y is mole fraction of P or +/?0.1 thereof. The two or more quantum well barriers have a GaAs1-zPz composition with z ranging from about 0.30 to about 0.60, where 0.45 can be optimal. The two or more quantum well barriers have a thickness of about 30 to 60 Angstroms.
    Type: Application
    Filed: January 14, 2013
    Publication date: July 17, 2014
    Applicant: FINISAR CORPORATION
    Inventors: Ralph H. Johnson, Gary Landry
  • Patent number: 8481350
    Abstract: Methods for fabricating an optical device that exhibits improved conduction and reflectivity, and minimized absorption. Steps include forming a plurality of mirror periods designed to reflect an optical field having peaks and nulls. The formation of a portion of the plurality of minor periods includes forming a first layer having a thickness of less than one-quarter wavelength of the optical field; forming a first compositional ramp on the first layer; and forming a second layer on the compositional ramp, the second layer having a different index of refraction than the first layer and having a thickness such that the nulls of the optical field occur within the second layer and not within the compositional ramp, and wherein forming the second layer further comprises heavily doping the second layer at a location of the nulls of the optical field.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: July 9, 2013
    Assignee: Finisar Corporation
    Inventors: Ralph H. Johnson, James Guenter
  • Patent number: 8455279
    Abstract: Methods for manufacturing a polarization pinned vertical cavity surface emitting laser (VCSEL). Steps include growing a lower mirror on a substrate; growing an active region on the lower mirror; growing an upper mirror on the active region; depositing a grating layer on the upper mirror; and etching a grating into the grating layer.
    Type: Grant
    Filed: August 15, 2011
    Date of Patent: June 4, 2013
    Assignee: Finisar Corporation
    Inventors: Ralph H. Johnson, James K. Guenter
  • Patent number: 8451875
    Abstract: A VCSEL with nearly planar intracavity contact. A bottom DBR mirror is formed on a substrate. A first conduction layer region is formed on the bottom DBR mirror. An active layer, including quantum wells, is on the first conduction layer region. A trench is formed into the active layer region. The trench is formed in a wagon wheel configuration with spokes providing mechanical support for the active layer region. The trench is etched approximately to the first conduction layer region. Proton implants are provided in the wagon wheel and configured to render the spokes of the wagon wheel insulating. A nearly planar electrical contact is formed as an intracavity contact for connecting the bottom of the active region to a power supply. The nearly planar electrical contact is formed in and about the trench.
    Type: Grant
    Filed: October 31, 2006
    Date of Patent: May 28, 2013
    Assignee: Finisar Corporation
    Inventor: Ralph H. Johnson
  • Patent number: 8325775
    Abstract: Semiconductor devices such as VCSELs, SELs, LEDs, and HBTs are manufactured to have a wide bandgap material near a narrow bandgap material. Electron injection is improved by an intermediate structure positioned between the wide bandgap material and the narrow bandgap material. The intermediate structure is an inflection, such as a plateau, in the ramping of the composition between the wide bandgap material and the narrow bandgap material. The intermediate structure is highly doped and has a composition with a desired low electron affinity. The injection structure can be used on the p-side of a device with a p-doped intermediate structure at high hole affinity.
    Type: Grant
    Filed: November 8, 2010
    Date of Patent: December 4, 2012
    Assignee: Finisar Corporation
    Inventor: Ralph H. Johnson
  • Publication number: 20120270346
    Abstract: Methods for fabricating an optical device that exhibits improved conduction and reflectivity, and minimized absorption. Steps include forming a plurality of mirror periods designed to reflect an optical field having peaks and nulls. The formation of a portion of the plurality of minor periods includes forming a first layer having a thickness of less than one-quarter wavelength of the optical field; forming a first compositional ramp on the first layer; and forming a second layer on the compositional ramp, the second layer having a different index of refraction than the first layer and having a thickness such that the nulls of the optical field occur within the second layer and not within the compositional ramp, and wherein forming the second layer further comprises heavily doping the second layer at a location of the nulls of the optical field.
    Type: Application
    Filed: June 29, 2012
    Publication date: October 25, 2012
    Applicant: FINISAR CORPORATION
    Inventors: Ralph H. Johnson, James Guenter
  • Publication number: 20120236892
    Abstract: A method for preparing a VCSEL can use MBE for: growing a first conduction region over a first mirror region; growing an active region over the first conduction region opposite of the first mirror region, including: (a) growing a quantum well barrier having In1-xGaxP(As); (b) growing an transitional layer having one or more of GaP, GaAsP, or GaAs; (c) growing a quantum well layer having In1-zGazAsyP1-y; (d) growing another transitional layer have one or more of GaP, GaAsP, or GaAs; (e) repeating processes (a) through (d) over a plurality of cycles; and (f) growing a quantum well barrier having In1-xGaxP(As); growing a second conduction region over the active region opposite of the first conduction region, wherein: x ranges from 0.77 to 0.50; y ranges from 0.7 to 1; and z ranges from 0.7 to 0.99.
    Type: Application
    Filed: March 19, 2012
    Publication date: September 20, 2012
    Applicant: FINISAR CORPORATION
    Inventors: Ralph H. Johnson, Jerome K. Wade
  • Publication number: 20120236891
    Abstract: A VCSEL can include: one or more quantum wells having (Al)InGaAs; two or more quantum well barriers having Al(In)GaAs bounding the one or more quantum well layers; and one or more transitional monolayers deposited between each quantum well layer and quantum well barrier, wherein the quantum wells, barriers and transitional monolayers are substantially devoid of traps. The one or more transitional monolayers include GaP, GaAs, and/or GaAsP. Alternatively, the VCSEL can include two or more transitional monolayers of AlInGaAs with a barrier-side monolayer having lower In and higher Al compared to a quantum well side monolayer that has higher In and lower Al.
    Type: Application
    Filed: March 19, 2012
    Publication date: September 20, 2012
    Applicant: FINISAR CORPORATION
    Inventors: Ralph H. Johnson, Jimmy Alan Tatum, Andrew N. MacInnes, Jerome K. Wade, Luke A. Graham
  • Patent number: 8254424
    Abstract: Methods for fabricating semiconductors with enhanced strain. One embodiment includes fabrication of a semiconductor device with an epitaxial structure. The epitaxial structure is formed with one or more semiconductor layers. One or more of the layers includes a dopant including small quantities of Al and repeated delta doping during expitaxial growth to form periods where surfaces are group III rich.
    Type: Grant
    Filed: December 20, 2010
    Date of Patent: August 28, 2012
    Assignee: Finisar Corporation
    Inventor: Ralph H. Johnson
  • Publication number: 20120213243
    Abstract: A VCSEL with undoped top mirror. The VCSEL is formed from an epitaxial structure deposited on a substrate, and a periodically doped conduction layer is coupled to the undoped top minor. A periodically doped spacer layer is coupled to an active region. An undoped bottom minor coupled to the periodically doped spacer layer. A first intracavity contact is coupled to the periodically doped conduction layer and a second intracavity contact is coupled to the periodically doped spacer layer.
    Type: Application
    Filed: April 30, 2012
    Publication date: August 23, 2012
    Applicant: FINISAR CORPORATION
    Inventors: Ralph H. Johnson, R. Scott Penner, James Robert Biard
  • Patent number: 8213474
    Abstract: An optical device for improving conduction and reflectivity and minimizing absorption. The optical device includes a first mirror comprising a first plurality of mirror periods designed to reflect an optical field at a predetermined wavelength, where the optical field has peaks and nulls. Each of the plurality of mirror periods includes a first layer of having a high carrier mobility, a second layer having lower carrier mobility, and a first compositional ramp between the first and second layers. The thicknesses of the first and second layers for at least a portion of the first plurality of mirror periods are established such that the nulls of the optical field occur within the first layer and not within the compositional ramp. At least the portion of the first layers within the first plurality of mirror periods include elevated doping concentrations at locations of the nulls of the optical field.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: July 3, 2012
    Assignee: Finisar Corporation
    Inventors: Ralph H. Johnson, James Guenter
  • Patent number: 8193019
    Abstract: A VCSEL with undoped mirrors. An essentially undoped bottom DBR mirror is formed on a substrate. A periodically doped first conduction layer region is formed on the bottom DBR mirror. The first conduction layer region is heavily doped at a location where the optical electric field is at about a minimum. An active layer, including quantum wells, is on the first conduction layer region. A periodically doped second conduction layer region is connected to the active layer. The second conduction layer region is heavily doped where the optical electric field is at a minimum. An aperture is formed in the epitaxial structure above the quantum wells. A top mirror coupled to the periodically doped second conduction layer region. The top mirror is essentially undoped and formed in a mesa structure. An oxide is formed around the mesa structure to protect the top mirror during wet oxidation processes.
    Type: Grant
    Filed: November 1, 2010
    Date of Patent: June 5, 2012
    Assignee: Finisar Corporation
    Inventors: Ralph H. Johnson, R. Scott Penner, James Robert Biard, Colby Fitzgerald
  • Patent number: 8168456
    Abstract: A VCSEL with undoped top mirror. The VCSEL is formed from an epitaxial structure deposited on a substrate. A doped bottom mirror is formed on the substrate. An active layer that includes quantum wells is formed on the bottom mirror. A periodically doped conduction layer is formed on the active layer. The periodically doped conduction layer is heavily doped at locations where the optical energy is at a minimum when the VCSEL is in operation. A current aperture is used between the conduction layer and the active region. An undoped top mirror is formed on the heavily doped conduction layer.
    Type: Grant
    Filed: December 27, 2010
    Date of Patent: May 1, 2012
    Assignee: Finisar Corporation
    Inventors: Ralph H. Johnson, R. Scott Penner, James Robert Biard
  • Publication number: 20110306156
    Abstract: Methods for manufacturing a polarization pinned vertical cavity surface emitting laser (VCSEL). Steps include growing a lower mirror on a substrate; growing an active region on the lower mirror; growing an upper mirror on the active region; depositing a grating layer on the upper minor; and etching a grating into the grating layer.
    Type: Application
    Filed: August 15, 2011
    Publication date: December 15, 2011
    Applicant: FINISAR CORPORATION
    Inventors: Ralph H. Johnson, James K. Guenter
  • Patent number: 8031752
    Abstract: A Vertical Cavity Surface Emitting Laser (VCSEL) is optimized for longer life of the VCSEL by controlling the distance of doped and undoped layers near an active region. In addition, the VCSEL optimized for reduced parasitic lateral current under an oxide of the VCSEL by forming a high Al confinement region and placing the oxide at a null in a standing optical wave. Further, the VCSEL is optimized to reduce resistance.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: October 4, 2011
    Assignee: Finisar Corporation
    Inventors: Ralph H. Johnson, James K. Guenter, James R. Biard
  • Patent number: 8000374
    Abstract: A polarization pinned vertical cavity surface emitting laser (VCSEL). A VCSEL designed to be polarization pinned includes an upper mirror. An active region is connected on the upper mirror. A lower mirror is connected to the active region. A grating layer is deposited to the upper mirror. The grating layer includes a low index of refraction layer formed by deposition on the upper mirror. The grating layer further includes a high index of refraction layer formed by deposition on the low index of refraction layer. A grating is formed into the grating layer.
    Type: Grant
    Filed: December 12, 2005
    Date of Patent: August 16, 2011
    Assignee: Finisar Corporation
    Inventors: Ralph H. Johnson, James K. Guenter