Richard R Stewart

US Patent:

20120250133, Oct 4, 2012

Filed:

Mar 19, 2012

Appl. No.:

13/423498

Inventors:

Richard E. Stewart - San Ramon CA, US
Stephen P. Vernon - Pleasanton CA, US
Paul T. Steele - Livermore CA, US
Mark E. Lowry - Castro Valley CA, US

Assignee:

Lawrence Livermore National Security, LLC - Livermore CA

International Classification:

G02B 26/00

US Classification:

359238

Abstract:

A high sensitivity transient grating ultrafast radiation to optical image converter is based on a fixed transmission grating adjacent to a semiconductor substrate. X-rays or optical radiation passing through the fixed transmission grating is thereby modulated and produces a small periodic variation of refractive index or transient grating in the semiconductor through carrier induced refractive index shifts. An optical or infrared probe beam tuned just below the semiconductor band gap is reflected off a high reflectivity mirror on the semiconductor so that it double passes therethrough and interacts with the radiation induced phase grating therein. A small portion of the optical beam is diffracted out of the probe beam by the radiation induced transient grating to become the converted signal that is imaged onto a detector.