Accession Number : ADD018046

Title :   Broadband Thermal Optical Limited for the Protection of Eyes and Sensors.

Descriptive Note : Patent, Filed 31 May 94, patented 13 Feb 96,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Justus, Brian L ; Huston, Alan L ; Campillo, Anthony J

Report Date : 13 Feb 1996

Pagination or Media Count : 14

Abstract : A broadband thermal optical limiter for protecting a light sensitive object from intense laser beams at all near ultraviolet, visible and near infrared wavelengths is disclosed. The broadband thermal optical limiter comprises: a sample cell containing a solution of broadband absorber material dissolved in a thermal solvent; and a first optical device for converging an incident laser beam into the sample cell. The sample cell is responsive to a converged incident laser beam below a predetermined intensity level for passing therethrough the converged incident laser beam below the predetermined intensity level. The sample cell is also responsive to a converged incident laser beam at or above a predetermined intensity level for thermally defocusing substantially all of the converged incident laser beam in different directions and passing therethrough only a remaining small portion of the converged incident laser beam at or above the predetermined intensity level. The broadband thermal optical limiter further includes a second optical device for focusing substantially all of the laser beam passing through the sample cell into the light-sensitive object to be protected. A collecting aperture may be disposed in front of the second optical device for substantially blocking all light deflected by the protective element and passing need therethrough into the second optical device only a small, portion of the focused incident light beam at or above the predetermined intensity level.

Descriptors :   *EYE SAFETY, *LIMITERS, *PATENTS, THERMAL PROPERTIES, OPTICAL PROPERTIES, INTENSITY, SENSITIVITY, LASER BEAMS, ABSORBERS(MATERIALS), BROADBAND, PROTECTION, FOCUSING, BLOCKING, NEAR INFRARED RADIATION, NEAR ULTRAVIOLET RADIATION

Subject Categories : Electrooptical and Optoelectronic Devices

Distribution Statement : APPROVED FOR PUBLIC RELEASE