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Hiroaki Ohta

from Goleta, CA
Age ~48
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Related to:
Yukiko Ohta
Connected to:
Allison M Ohta, 39Andrea E Ohta, 43Jun Ohta, 87Lisa H Ohta, 41Miki M Ohta, 88Ted H Ohta, 61Teri Y Ohta, 58Takuya Ohtani, 54Yumi Ohtani, 54Danielle Ohtola, 35

Hiroaki Ohta Phones & Addresses

  • Goleta, CA

Publications

Us Patents

Anisotropic Strain Control In Semipolar Nitride Quantum Wells By Partially Or Fully Relaxed Aluminum Indium Gallium Nitride Layers With Misfit Dislocations

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US Patent:
8481991, Jul 9, 2013
Filed:
Aug 23, 2010
Appl. No.:
12/861652
Inventors:
Hiroaki Ohta - Goleta CA, US
Feng Wu - Goleta CA, US
Anurag Tyagi - Goleta CA, US
Arpan Chakraborty - Goleta CA, US
James S. Speck - Goleta CA, US
Steven P. DenBaars - Goleta CA, US
Shuji Nakamura - Santa Barbara CA, US
Erin C. Young - Santa Barbara CA, US
Assignee:
The Regents of the University of California - Oakland CA
International Classification:
H01L 29/66
US Classification:
257 14, 257E29168, 257E2109, 438 47
Abstract:
An epitaxial structure for a III-Nitride based optical device, comprising an active layer with anisotropic strain on an underlying layer, where a lattice constant and strain in the underlying layer are partially or fully relaxed in at least one direction due to a presence of misfit dislocations, so that the anisotropic strain in the active layer is modulated by the underlying layer.

Structure For Improving The Mirror Facet Cleaving Yield Of (Ga,Al,In,B)N Laser Diodes Grown On Nonpolar Or Semipolar (Ga,Al,In,B)N Substrates

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US Patent:
20110007766, Jan 13, 2011
Filed:
Jul 9, 2010
Appl. No.:
12/833607
Inventors:
Robert M. Farrell - Goleta CA, US
Matthew T. Hardy - Goleta CA, US
Hiroaki Ohta - Goleta CA, US
Steven P. DenBaars - Goleta CA, US
James S. Speck - Goleta CA, US
Shuji Nakamura - Santa Barbara CA, US
Assignee:
THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA
International Classification:
H01S 5/343
H01S 5/34
H01L 33/04
H01L 33/30
US Classification:
372 4501, 438 31, 977755, 977951, 257E33067, 438 47, 257E33005, 257E33023
Abstract:
A structure for improving the mirror facet cleaving yield of (Ga,Al,In,B)N laser diodes grown on nonpolar or semipolar (Ga,Al,In,B)N substrates. The structure comprises a nonpolar or semipolar (Ga,Al,In,B)N laser diode including a waveguide core that provides sufficient optical confinement for the device's operation in the absence of p-type doped aluminum-containing waveguide cladding layers, and one of more n-type doped aluminum-containing layers that can be used to assist with facet cleaving along a particular crystallographic plane.

Semipolar Nitride-Based Devices On Partially Or Fully Relaxed Alloys With Misfit Dislocations At The Heterointerface

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US Patent:
20110064103, Mar 17, 2011
Filed:
Aug 23, 2010
Appl. No.:
12/861532
Inventors:
Hiroaki Ohta - Goleta CA, US
Feng Wu - Goleta CA, US
Anurag Tyagi - Goleta CA, US
Arpan Chakraborty - Goleta CA, US
James S. Speck - Goleta CA, US
Steven P. DenBaars - Goleta CA, US
Shuji Nakamura - Santa Barbara CA, US
Erin C. Young - Santa Barbara CA, US
Assignee:
THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA
International Classification:
H01S 5/343
H01L 33/04
C30B 23/02
C30B 25/02
B82Y 20/00
US Classification:
372 4501, 257 13, 117108, 117104, 257E33008, 977755, 977951
Abstract:
A dislocation-free high quality template with relaxed lattice constant, fabricated by spatially restricting misfit dislocation(s) around heterointerfaces. This can be used as a template layer for high In composition devices. Specifically, the present invention prepares high quality InGaN templates (In composition is around 5-10%), and can grow much higher In-composition InGaN quantum wells (QWs) (or multi quantum wells (MQWs)) on these templates than would otherwise be possible.

Superluminescent Diodes By Crystallographic Etching

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US Patent:
20110103418, May 5, 2011
Filed:
Oct 27, 2010
Appl. No.:
12/913638
Inventors:
Matthew T. Hardy - Goleta CA, US
You-Da Lin - Goleta CA, US
Hiroaki Ohta - Goleta CA, US
Steven P. DenBaars - Goleta CA, US
James S. Speck - Goleta CA, US
Shuji Nakamura - Santa Barbara CA, US
Kathryn M. Kelchner - Santa Barbara CA, US
Assignee:
THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA
International Classification:
H01S 5/323
H01L 33/22
H01L 21/302
US Classification:
372 4401, 257 98, 438 29, 257E33074, 257E21214
Abstract:
An optoelectronic device, comprising an active region and a waveguide structure to provide optical confinement of light emitted from the active region; a pair of facets on opposite ends of the device, having opposite surface polarity; and one of the facets which has been roughened by a crystallographic chemical etching process, wherein the device is a nonpolar or semipolar (Ga,In,Al,B)N based device.

Semipolar Iii-Nitride Laser Diodes With Etched Mirrors

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US Patent:
20110170569, Jul 14, 2011
Filed:
Oct 20, 2010
Appl. No.:
12/908478
Inventors:
Anurag Tyagi - Goleta CA, US
Robert M. Farrell - Goleta CA, US
Chia-Yen Huang - Goleta CA, US
Po Shan Hsu - Arcadia CA, US
Daniel A. Haeger - Goleta CA, US
Kathryn M. Kelchner - Santa Barbara CA, US
Hiroaki Ohta - Goleta CA, US
Shuji Nakamura - Santa Barbara CA, US
Steven P. DenBaars - Goleta CA, US
James S. Speck - Goleta CA, US
Assignee:
THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA
International Classification:
H01S 5/323
H01L 33/02
H01L 33/60
H01S 5/00
H01S 5/183
US Classification:
372 45013, 438 46, 438 29, 372 4401, 257E33023, 257E33068
Abstract:
A semipolar {20-21} III-nitride based laser diode employing a cavity with one or more etched facet mirrors. The etched facet mirrors provide an ability to arbitrarily control the orientation and dimensions of the cavity or stripe of the laser diode, thereby enabling control of electrical and optical properties of the laser diode.
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Hiroaki Ohta from Goleta, CA, age ~48 Get Report