Patents by Inventor Ralph Johnson

Ralph 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: 20070098032
    Abstract: A polarization pinned long wavelength vertical cavity surface emitting laser (VCSEL). The VCSEL includes a III V semiconductor substrate. A bottom DBR mirror is formed on the semiconductor substrate. An active region is formed in an off-axis orientation on the bottom DBR mirror. The active region includes a surfactant that suppresses unwanted three dimensional growth. A top DBR mirror formed on the active region.
    Type: Application
    Filed: October 13, 2006
    Publication date: May 3, 2007
    Applicant: Finisar Corporation
    Inventor: Ralph Johnson
  • Publication number: 20070070645
    Abstract: An LED light source (10) comprises a heat sink (12) having a body (14) with a front surface (16) and a rear surface (18), the rear surface (18) being provided with heat dissipaters (20). The front surface (16) includes a pocket (22) for the receipt of components (24), the components including at least one LEDs (25) and electrical circuitry therefor. A housing (26) has a flange (28) and a tubular projection (30) fitted into the pocket (22) in a manner to fix the components (24) in the heat sink (12); and an optical light guide (32) having at least one light pipes (34) is positioned in the tubular projection (30), each of the at least one light pipes (34) having a light input end (34a) fixed in light gathering alignment with the at least one LEDs (25) in a one-to-one relationship.
    Type: Application
    Filed: June 29, 2006
    Publication date: March 29, 2007
    Inventors: Charles Coushaine, Ralph Johnson, Thomas Tessnow
  • Publication number: 20070053399
    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: Application
    Filed: October 30, 2006
    Publication date: March 8, 2007
    Applicant: FINISAR CORPORATION
    Inventors: Ralph Johnson, R. Penner, James Biard
  • Publication number: 20060268954
    Abstract: Light emitting semiconductor devices such as VCSELs, SELs, and LEDs are manufactured to have a thin electrical confinement barrier in a confining layer near the active region of the device. The thin confinement barrier comprises a III-V semiconductor material having a high aluminum content (e.g. 80%-100% of the type III material). The aluminum content of the adjacent spacer layer is lower than that of the confinement barrier. In one embodiment the spacer layer has an aluminum content of less than 40% and a direct bandgap. The aluminum profile reduces series resistance and improves the efficiency of the semiconductor device.
    Type: Application
    Filed: July 31, 2006
    Publication date: November 30, 2006
    Inventors: Ralph Johnson, James Biard, James Guenter
  • Publication number: 20060246700
    Abstract: Methods and systems produce flattening layers associated with nitrogen-containing quantum wells and prevent 3-D growth of nitrogen containing layers using controlled group V fluxes and temperatures. MEE (Migration Enhanced Epitaxy) is used to form a flattening layer upon which a quantum well is formed and thereby enhance smoothness of quantum well interfaces and to achieve narrowing of the spectrum of light emitted from nitrogen containing quantum wells. MEE is performed by alternately depositing single atomic layers of group III and V materials at a given group V flux and then raising the group V flux to saturate the surface of the flattening layer with the group V material. A cap layer is also formed over the quantum well. Where nitrogen is used, the systems incorporate a mechanical means of preventing nitrogen from entering the MBE processing chamber, such as a gate valve.
    Type: Application
    Filed: July 11, 2006
    Publication date: November 2, 2006
    Inventor: Ralph Johnson
  • Publication number: 20060239325
    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: Application
    Filed: December 12, 2005
    Publication date: October 26, 2006
    Inventors: Ralph Johnson, James Guenter
  • Publication number: 20060221613
    Abstract: A virtual point light source (10) has a support (12) having an axis (14), a plurality of individual light emitting diodes (16) positioned on the support (12); and an individual optic (18) associated with each of the light emitting diodes (16), each of the individual optics (18) focusing the light from its associated light emitting diode (16) to a virtual point (20) on the axis (14) at a distance (D) from said support.
    Type: Application
    Filed: April 5, 2005
    Publication date: October 5, 2006
    Inventors: Charles Coushaine, Michael Tucker, Thomas Tessnow, Ralph Johnson, Steven Sidwell
  • Publication number: 20060198412
    Abstract: This disclosure concerns grating-coupled surface emitting (GSE) lasers with Gallium Arsenide (GaAs) substrates. In one example, a GSE laser includes a GaAs substrate, a lower cladding layer disposed on the substrate, a Dilute Nitride active region disposed on the lower cladding layer, and an upper cladding layer disposed on the active region.
    Type: Application
    Filed: March 7, 2006
    Publication date: September 7, 2006
    Inventor: Ralph Johnson
  • Publication number: 20060087861
    Abstract: A light gathering module (10) has a body (12) with a first end (14) comprising a single light transmitting surface (16) and a second end (18) having a plurality of arms (20), each arm (20) having an independent light gathering terminus (22) that is rectangular. In a preferred embodiment of the invention, the first end (14) of the body also is rectangular. The light gathering module (10) can be fabricated from acrylic, plastic, glass or other suitable material and preferably has no cladding so that light output I maximized. When combined in a housing (32) with a projector lens (34) the light gathering module (10) provides a vehicle headlamp (30).
    Type: Application
    Filed: May 3, 2005
    Publication date: April 27, 2006
    Inventors: Thomas Tessnow, Michael Tucker, Ralph Johnson, Steven Sidwell
  • Publication number: 20060072640
    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: Application
    Filed: September 12, 2005
    Publication date: April 6, 2006
    Inventors: Ralph Johnson, R. Penner, James Biard, Colby Fitzgerald
  • Publication number: 20060072639
    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: Application
    Filed: September 8, 2005
    Publication date: April 6, 2006
    Inventors: Ralph Johnson, R. Penner, James Biard
  • Publication number: 20060061988
    Abstract: A reflector lamp assembly may be formed with a reflector housing having a reflector with a prescribed reflective surface; the reflector formed with a wall defining a through passage. A lamp bulb assembly having an axially extending stem supports a head extending transverse to the axis, the head having a first generally linearly extending region, a first set of LEDs mounted generally in a row along the region oriented to face in one plane towards a reflector. Electrical connections for the LEDs extend through the head, and stem to the exterior of the assembly for electrical connection. A base extends in the through passage and is mechanically mounted to the optical housing with the LED assembly oriented to face the reflective surface.
    Type: Application
    Filed: September 23, 2004
    Publication date: March 23, 2006
    Inventors: Ralph Johnson, Paul Lyman
  • Publication number: 20060054902
    Abstract: Systems and methods for improving the temperature performance of AlInGaP based light emitters. Nitrogen is added to the quantum wells in small quantities. Nitrogen is added in a range of about 0.5 percent to 2 percent. The addition of nitrogen increases the conduction band offset and increases the separation of the indirect conduction band. To keep the emission wavelength in a particular range, the concentration of In in the quantum wells may be decreased or the concentration of Al in the quantum wells may be increased. Because the depth of the quantum wells in the valence band is more than is required although the addition of nitrogen reduces the depth of the quantum wells in the valence band. The net result is an increase in the conduction band offset and an increase in the separation of the indirect conduction band.
    Type: Application
    Filed: September 14, 2004
    Publication date: March 16, 2006
    Inventor: Ralph Johnson
  • Publication number: 20060045162
    Abstract: A Distributed Bragg Reflector (DBR) that has relatively low light absorption, relatively low electrical resistance, and/or relatively good thermal conductivity. The DBR may include a first mirror layer and a second mirror layer, with an interface therebetween. A step transition is provided in the aluminum concentration and in the doping concentration at or near the interface between the first mirror layer and the second mirror layer. To reduce optical absorption, the interface between the first and second mirror layers may be positioned at or near a null in the optical electric field within the DBR. A graded junction may also be provided. The graded junction may be more lightly doped, have a graded aluminum concentration, and may be placed at or near a peak in the optical electric field.
    Type: Application
    Filed: March 28, 2005
    Publication date: March 2, 2006
    Inventor: Ralph Johnson
  • Publication number: 20050281025
    Abstract: A high-density LED array (10) capable of presenting a density of X LEDs/unit area has a first printed circuit board (12) having X/2 LEDs/area and X/2 apertures arrayed therewith. A second printed circuit board (22) is spaced from the first printed circuit board (12) and has X/2 LEDs 28/unit area. The LEDs (28) on the second printed circuit board are aligned with the apertures (20) in the first printed circuit board. Each of the LEDs (28) on the second printed circuit board (22) has an optical fiber (30) associated therewith and each of the light guides (30) extends through one of the apterures (20). Each of the mounted LEDs on the first printed circuit board can have an optical fiber associated therewith and the light guides can be bundled to direct light to a remote source.
    Type: Application
    Filed: November 9, 2004
    Publication date: December 22, 2005
    Inventors: Charles Coushaine, Michael Tucker, Thomas Tessnow, Ralph Johnson, Steven Sidwell
  • Publication number: 20050281048
    Abstract: A lamp component has a support with a base surrounded by an interior wall defining a cavity with a central axis. A plurality of LEDs are supported on the interior wall and generally aimed to direct light towards the central axis. A center piece has a first reflective surface shaped and positioned to intercept light received from the LEDs and reflect such received light generally in a direction parallel to the axis.
    Type: Application
    Filed: May 9, 2005
    Publication date: December 22, 2005
    Inventors: Charles Coushaine, Michael Tucker, Thomas Tessnow, Ralph Johnson, Steven Sidwell
  • Publication number: 20050243888
    Abstract: Disclosed is a structure for an active region of a GaAs based VCSEL with strong optical output substantially within the range of 1.3 ?m and potentially for the 1.5 um range, making it well suited for the transmissivity of silica core fiberoptics. The active region of the VCSEL incorporates antimony in the quantum wells and portions of the barriers. The presence of Sb substantially smooths the surface of the barriers and quantum wells during the process of beam epitaxy, causing a higher critical thickness of each of the layers, thereby enabling fabrication with significantly reduced defects.
    Type: Application
    Filed: April 30, 2004
    Publication date: November 3, 2005
    Inventor: Ralph Johnson
  • Publication number: 20050190812
    Abstract: This disclosure concerns devices such as DBRs, one example of which includes at least one first mirror layers having an oxidized region extending from an edge of the DBR to an oxide termination edge that is situated greater than a first distance from the edge of the DBR. The DBR also includes at least one second mirror layer having an oxidized region extending from the edge of the DBR to an oxide termination edge that is situated less than a second distance from the edge of the DBR, such that the first distance is greater than the second distance. Additionally, a first mirror layer includes an oxidizable material at a concentration that is higher than the concentration of the oxidizable material in any of the second mirror layers. Finally, a first mirror layer is doped with an impurity at a higher level than one of the second mirror layers.
    Type: Application
    Filed: April 29, 2005
    Publication date: September 1, 2005
    Inventors: Ralph Johnson, Klein Johnson, Jimmy Tatum, James Guenter, James Biard, Robert Hawthorne
  • Publication number: 20050157765
    Abstract: A laser system having migration enhanced epitaxy grown substantially flat layers proximate to quantum wells of an active region. The flat layers may be grown at low temperature. This growth may result in flatter interfaces in the nitrogen containing quantum wells within the active region as well as lower trap densities in adjacent material. This may achieve a reduced trap density as well as reduced segregation resulting in a spectral luminescence profile revealing a single narrow peak with a high level of photoluminescence.
    Type: Application
    Filed: March 14, 2005
    Publication date: July 21, 2005
    Inventor: Ralph Johnson
  • Publication number: 20050142683
    Abstract: Methods and systems produce flattening layers associated with nitrogen-containing quantum wells and prevent 3-D growth of nitrogen containing layers using high As fluxes. MEE (Migration Enhanced Epitaxy) is used to flatten layers and enhance smoothness of quantum well interfaces and to achieve narrowing of the spectrum of light emitted from nitrogen containing quantum wells. MEE is performed by alternately depositing single atomic layers of group III and V before, and/or after, and/or in-between quantum wells. Where GaAs is used, the process can be accomplished by alternately opening and closing Ga and As shutters in an MBE system, while preventing both from being open at the same time. Where nitrogen is used, the system incorporates a mechanical means of preventing nitrogen from entering the MBE processing chamber, such as a gate valve.
    Type: Application
    Filed: August 31, 2004
    Publication date: June 30, 2005
    Inventors: Ralph Johnson, Virgil Blasingame