Optical thin-film cavities for transducing visible radiation to infrared

Abstract

A transducer is deposited on each fiber of an optical fiber scene projector to convert portions of electromagnetic radiation to emitted radiation, h as IR. The transducer, is adaptable to large arrays of optical fibers and can be fabricated using mature conventional processes, such as vapor deposition, for example. The components of the transducer can be tailored to handle different incident radiation and produce desired emitted radiation. Dielectric layers having thicknesses equal to odd-numbered multiples of quarter wavelengths of the electromagnetic radiation receive the electromagnetic radiation and a reflector adjacent to the layers reflects unabsorbed portions of radiation back through the layers. An absorber layer interposed between adjacent dielectric layers absorbs the received and the reflected radiation so as to convert the absorbed radiation into heat energy. Second dielectric layers having thicknesses equal to odd-numbered multiples of quarter wavelengths of desired emitted radiation are deposited adjacent to the reflector. A second absorber layer interposed between the adjacent layers of the second dielectric layers absorbs the heat energy and converts it to the emitted radiation, such as IR, although, other wavelengths could be emitted depending on the dimensions and materials used. Different number of layers may be included as needed to modify the emitted radiation.