John H Goebel

US Patent:

6838669, Jan 4, 2005

Filed:

Apr 25, 2002

Appl. No.:

10/135014

Inventors:

John H. Goebel - Foster City CA, US

Assignee:

The United States of America as represented by the Administrator of the National Aeronautics and Space Administration - Washington DC

International Classification:

G01J 520
G01J 524

US Classification:

2503384, 2503381

Abstract:

Bolometer system and method for detecting, at BLIP levels, presence of radiation over a broad range of wavelengths in an infrared spectrum and in a temperature range from 20 K to as high as room temperature. The radiation is received by a Si crystal having a region that is doped with one or more of In, Ga, S, Se, Te, B, Al, P, As and Sb in a concentration ratio in a range such as 5×10to 5×10. Change in electrical resistance ΔR due to receipt of the radiation is measured through a change in voltage difference or current within the crystal, and the quantity ΔR is converted to an estimate of the amount of radiation received. Optionally, incident radiation having an energy high enough to promote photoconductivity is removed before detection.