Accession Number : ADD014238

Title :   Narrow Band and Wide Angle Hemispherical Interference Optical Filter.

Descriptive Note : Patent, Filed 27 Jun 88, patented 25 Jul 89,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Rieger, Harry

Report Date : 25 Jul 1989

Pagination or Media Count : 8

Abstract : An optical interference filter has narrow linewidth and wide acceptance angle and includes a hemisphere coated to provide a narrow bandpass filter at a desired wavelength at normal incidence while other wavelengths at normal incidence are absorbed or reflected. A photodetector placed at the center of the hemisphere detects the desired wavelength only. Other wavelengths that are shorter than the wavelength of the filter are transmitted through the filter to be absorbed by a black absorbing surface around the photodetector. Thus, only the frequency of interest at normal incidence provides a representative signal at the detector. Patents. (RRH)

Descriptors :   *BANDPASS FILTERS, *INTERFERENCE, *NARROWBAND, *OPTICAL FILTERS, *PATENTS, *PHOTODETECTORS, ACCEPTABILITY, DETECTORS, FILTERS, FREQUENCY, HEMISPHERES, SIGNALS, SPECTRAL LINES, WIDE ANGLES, ACCEPTABILITY, BANDPASS FILTERS, DETECTORS, FILTERS, FREQUENCY, HEMISPHERES, INTERFERENCE, NARROWBAND, OPTICAL FILTERS, PATENTS, PHOTODETECTORS, SIGNALS, SPECTRAL LINES, WIDE ANGLES

Subject Categories : Optics
      Optical Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE