Accession Number : ADD016059

Title :   Discrete Vacuum Ultra Violet Reflective Interference Filter.

Descriptive Note : Patent Application, Filed 27 Jun 93,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Hunter, William R ; Long, James P

Report Date : 27 Jun 1993

Pagination or Media Count : 22

Abstract : A thin film reflecting interference filter (RIF) is designed to suppress unwanted harmonics thereby improving the monochromaticity of the radiation. An interference layer of material which has a well-defined plasma oscillation is deposited on a substrate and a mismatch layer is formed thereon. This interference layer exploits the interference between wavefronts reflected from the layer-substrate and the vacuum-layer interfaces to suppress higher order harmonics, while allowing good reflectance at the fundamental wavelength. This is achieved by positioning the RIF in the radiation at an angle of incidence which is greater than the critical angle of the desired fundamental wavelength, but less than critical angles of the harmonics to be suppressed. The mismatch layer increases the reflectance of the unwanted harmonics at the vacuum-layer interface, thus allowing more complete destructive interference of the unwanted harmonics. The RIF can be tuned by altering the thickness of the layer, the composition of the layer and/or the angle of incidence of the radiation. (Author)

Descriptors :   *PATENT APPLICATIONS, *FILTERS, *INTERFERENCE, *VACUUM ULTRAVIOLET RADIATION, *ULTRAVIOLET SPECTRA, THIN FILMS, REFLECTIVITY, LAYERS, PLASMA OSCILLATION, SUBSTRATES, WAVEFRONTS, HARMONICS, ANGLE OF INCIDENCE

Subject Categories : Solid State Physics
      Pumps, Filters, Pipes, Tubing, Fittings & Vlvs
      Optics
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE