David C Wei

US Patent:

7297966, Nov 20, 2007

Filed:

Aug 16, 2005

Appl. No.:

11/205782

Inventors:

David T. Wei - Malibu CA, US
Axel Scherer - Laguna Beach CA, US

Assignee:

California Institute of Technology - Pasadena CA

International Classification:

G01J 3/45
G01N 13/00

US Classification:

2504922, 250397, 250399, 356445, 356451, 345 87, 345 77

Abstract:

A method for monitoring the surface roughness of a metal, comprises impinging a laser beam onto the surface of a metal layer to induce the formation of a plasmon therein, and monitoring a current of decay electrons emitted by the plasmon.

US Patent:

7495230, Feb 24, 2009

Filed:

Aug 16, 2005

Appl. No.:

11/205781

Inventors:

David T. Wei - Malibu CA, US
Axel Scherer - Laguna Beach CA, US

Assignee:

California Institute of Technology - Pasadena CA

International Classification:

G01K 1/08

US Classification:

250397, 2504922, 356445

Abstract:

An integrated plasmon detector includes a top layer of material adapted to generate a plasmon when excited by a beam of light incident onto a surface of the top layer, an interface layer joined to the top layer opposite from the surface of the top layer and adapted to slow polarons emitted by the plasmon to thermal electrons, and a collector layer joined to the interface layer opposite from the top layer and adapted to collect the thermal electrons from the interface layer.

US Patent:

7693052, Apr 6, 2010

Filed:

Aug 17, 2005

Appl. No.:

11/206445

Inventors:

Cheng Jin - Pasadena CA, US
Steven H. Low - La Canada CA, US
David X. Wei - Pasadena CA, US
Bartek Wydrowski - Altadena CA, US
Ao Tang - Pasadena CA, US
Hyojeong Choe - Gyeonggi-do, KR

Assignee:

California Institute of Technology - Pasadena CA

International Classification:

G01R 31/08

US Classification:

370230

Abstract:

The invention provides a congestion control scheme that is a delay based scheme that includes a scalable queue size and one-way queueing delay measurement to reduce network congestion. Queue size is managed by queue control, a scalable utility function, dynamic alpha tuning, and/or randomized alpha tuning. One-way queueing delay is accomplished by measuring backward queueing delay management using various methods of estimating the receiver clock period. Embodiments include estimating the receiver clock period using single sample and multiple sample periods. The system includes a method for detecting route change.

US Patent:

RE328499, Jan 31, 1989

Filed:

Jul 2, 1985

Appl. No.:

6/751218

Inventors:

David T. Wei - Malibu CA
Anthony W. Louderback - Ojai CA

Assignee:

Litton Systems, Inc. - Woodland Hills CA

International Classification:

C23C 1446

US Classification:

20419227

Abstract:

A method for fabricating multiple layer interference optical films by ion beam sputtering, said films being used for mirrors in a ring laser apparatus. An ion beam strikes a target material obliquely, dislodging molecules of the target so that they can be deposited on a surface serving as a base for a multiple layer interference coating. The thickness of the coating is monitored so that the proper thickness of a given layer can be optimized to obtain the type of reflectance desired for a given light wave length. The surface to be coated is rotated during the deposition of the layer of target material. A stack of layers of alternating indices of refraction comprises the optical interference film. The coating process occurs inside of a vacuum chamber where the partial pressures of the gases are carefully controlled to insure the proper ion beam intensity and optimum stoichiometry of the deposited optical films. Prior to beginning the deposition of optical films, the ceramic substrate comprising the mirror base is bombarded by the ion beam at an oblique angle to remove surface anomalies and clean it.

US Patent:

61905119, Feb 20, 2001

Filed:

Feb 6, 1998

Appl. No.:

9/020195

Inventors:

David T. Wei - Malibu CA

International Classification:

C23C 1434

US Classification:

20419211

Abstract:

A technique for ion beam sputter deposition of optical coatings. The technique includes the following features (i) an assist chemical emitted towards the sputter target to oppose the tendency of film growth on the target; (ii) a discriminate baffle to capture ions or assist chemicals reflected from the target; (iii) a screen chemical to protect the coating area from the assist chemical; (iv) compartmentalized of the coating chamber to reduce crossing effects between the different chemicals (D. W. ) (C. L. ); (v) a compartmentalized assist ion beam to modify the coating and to reduce microstructure, defects and impurities in the coating (D. W. ) (C. L. ); and (vi) to combine the above features or multiply use one of the above features to further advantage or to increase throughput.

US Patent:

41429583, Mar 6, 1979

Filed:

Apr 13, 1978

Appl. No.:

5/896133

Inventors:

David T. Wei - Malibu CA
Anthony W. Louderback - Ojai CA

Assignee:

Litton Systems, Inc. - Woodland Hills CA

International Classification:

C23C 1500

US Classification:

204192P

Abstract:

A method for fabricating multiple layer interference optical films by ion beam sputtering, said films being used for mirrors in a ring laser apparatus. An ion beam strikes a target material obliquely, dislodging molecules of the target so that they can be deposited on a surface serving as a base for a multiple layer interference coating. The thickness of the coating is monitored so that the proper thickness of a given layer can be optimized to obtain the type of reflectance desired for a given light wave length. The surface to be coated is rotated during the deposition of the layer of target material. A stack of layers of alternating indices of refraction comprises the optical interference film. The coating process occurs inside of a vacuum chamber where the partial pressures of the gases are carefully controlled to insure the proper ion beam intensity and optimum stoichiometry of the deposited optical films. Prior to beginning the deposition of optical films, the ceramic substrate comprising the mirror base is bombarded by the ion beam at an oblique angle to remove surface anomalies and clean it.