Lawrence P Ho

US Patent:

7359046, Apr 15, 2008

Filed:

Apr 12, 2006

Appl. No.:

11/402357

Inventors:

Gregory J. Steckman - Glendora CA, US
Frank Havermeyer - Arcadia CA, US
Lawrence Pokwah Ho - Arcadia CA, US

Assignee:

Ondax, Inc. - Monrovia CA

International Classification:

G01N 21/00

US Classification:

3562391, 3562392

Abstract:

The invention describes a system for the measurement of volume holograms on a wafer scale that permits high-resolution and high throughput measurement of grating parameters. The invention uses a collimated beam of a fixed wavelength light source that is transmitted through the wafer to be tested. The transmitted beam is imaged with a lens onto a sensor. The sensor is used to measure the beam power under a variety of conditions, including without a wafer in place, so that the various measurements can be used to determine grating characteristics. The measurement data produced includes values for grating spacing, tilt angle, and diffraction efficiency with a high spatial resolution.

US Patent:

7636376, Dec 22, 2009

Filed:

May 23, 2008

Appl. No.:

12/154636

Inventors:

Christophe Moser - Pasadena CA, US
Frank Havermeyer - Arcadia CA, US
Lawrence Pokwah Ho - Arcadia CA, US

Assignee:

Ondax, Inc. - Monrovia CA

International Classification:

H01S 3/10
H01S 3/08

US Classification:

372 20, 372 21, 372101, 372102

Abstract:

A method is presented for shaping the spectral response of volume holographic grating elements by applying controlled thermal energy. The methods allow generating continuous or discontinuous grating periods from a fixed grating period. The methods are applicable to optical feedback into optical sources such as light emitting diodes, lasers and other general optical filtering applications.

US Patent:

58419934, Nov 24, 1998

Filed:

Jan 2, 1996

Appl. No.:

8/582114

Inventors:

Lawrence Ho - Arcadia CA

International Classification:

G11B 2002

US Classification:

395282

Abstract:

A surround sound system for personal computer includes a control card and a PC surround decoder. The control card is a PC interface card for interfacing to the personal computer and draining the 5 VDC and. +-. 12 VDC power from the personal computer as power source for both the control card and the PC surround decoder to operate. The PC surround decoder for processing the stereo source signal and generating left, center, right, surround and subwoofer signals. A connecting means electrically connects the PC surround decoder to the control card. The PC surround sound system is specified for incorporating with personal computer which enables the users to command the PC surround sound system with their computer keyboard or mouse and receive the full benefit of Dolby Surround encoded multimedia software and the like.

US Patent:

20170191939, Jul 6, 2017

Filed:

Mar 20, 2017

Appl. No.:

15/464114

Inventors:

- Monrovia CA, US
Lawrence Ho - Arcadia CA, US
Frank Havermeyer - La Verne CA, US
Eric Maye - Torrance CA, US
Randy Heyler - Newport Beach CA, US

International Classification:

G01N 21/65

Abstract:

Provided are methods and systems for identification and analysis of materials and molecular structures. An apparatus for identification and analysis of materials and molecular structures may include a laser. The laser may, in turn, include an amplified spontaneous emission-suppressed single-frequency laser excitation source. The apparatus may further comprise a plurality of filters. The plurality of filters may include reflective volume holographic grating blocking filters. The apparatus may also comprise an optical unit and an optical spectrometer. The optical unit may be configured to deliver excitation energy to a sample substance and capture Raman signal scattering from the sample substance. The optical spectrometer may be disposed in a path of the Raman signal and configured to measure a spectrum of the Raman signal and generate a detection signal. Finally, the apparatus may comprise a processing unit configured to analyze the spectrum.