Ganapathi S Subramania

US Patent:

6339030, Jan 15, 2002

Filed:

Jan 5, 2000

Appl. No.:

09/477191

Inventors:

Kristen Constant - Ames IA
Ganapathi S. Subramania - Ames IA
Rana Biswas - Ames IA
Kai-Ming Ho - Ames IA

Assignee:

The United States of America as represented by the United States Department of Energy - Washington DC

International Classification:

H01L 2131

US Classification:

438758, 438 7, 438 16, 438 22, 438 29, 257 9, 257 10, 257 13, 257 76, 257918

Abstract:

A method for forming a periodic dielectric structure exhibiting photonic band gap effects includes forming a slurry of a nano-crystalline ceramic dielectric or semiconductor material and monodisperse polymer microspheres, depositing a film of the slurry on a substrate, drying the film, and calcining the film to remove the polymer microspheres therefrom. The film may be cold-pressed after drying and prior to calcining. The ceramic dielectric or semiconductor material may be titania, and the polymer microspheres may be polystyrene microspheres.

US Patent:

20140219306, Aug 7, 2014

Filed:

Feb 3, 2014

Appl. No.:

14/171231

Inventors:

- Albuquerque NM, US
Igal Brener - Albuquerque NM, US
Ganapathi S. Subramania - Albuquerque NM, US
George T. Wang - Albuquerque NM, US
Qiming Li - Shanghai, CN

Assignee:

Sandia Corporation - Albuquerque NM

International Classification:

H01S 5/323
H01S 5/343

US Classification:

372 45012

Abstract:

A multicolor photonic crystal laser array comprises pixels of monolithically grown gain sections each with a different emission centre wavelength. As an example, two-dimensional surface-emitting photonic crystal lasers comprising broad gain-bandwidth III-nitride multiple quantum well axial heterostructures were fabricated using a novel top-down nanowire fabrication method. Single-mode lasing was obtained in the blue-violet spectral region with 60 nm of tuning (or 16% of the nominal centre wavelength) that was determined purely by the photonic crystal geometry. This approach can be extended to cover the entire visible spectrum.