Accession Number : AD0778096

Title :   A Fully Tunable Lyot-Ohman Filter.

Descriptive Note : Interim rept.,

Corporate Author : AIR FORCE CAMBRIDGE RESEARCH LABS L G HANSCOM FIELD MASS

Personal Author(s) : Beckers,Jacques M.

Report Date : MAR 1973

Pagination or Media Count : 17

Abstract : Incorporation of achromatic wave plates into the Lyot-Ohman type of birefringent filter and the introduction of computer control has made it possible to manufacture filters of that type which are rapidly tunable over a wide spectral range. This so-called Universal Birefringent Filter is now in use at the Sacramento Peak Observatory. It can be tuned within 2 seconds to any wavelength in the 4100 - 7100 A wavelength range. The initial bandwidth, which varies from 0.28 A at 7100 to 0.08 A at 4100 A, can be decreased by the addition of an extra filter element to 0.14 at 7100 A and 0.04 A at 4100 A. Peak transmission varies from 8 percent in the 5000 - 7000 A range to 2 percent at 4200 A. This filter, as part of the Sacramento Peak Observatory vacuum telescope, will be used for observation of solar intensity, velocity and magnetic fields. (Author)

Descriptors :   *Optical filters, *Telescopes, Tuning, Birefringence, Astronomical instruments

Subject Categories : Astrophysics
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE