Title :
A double-element broad-band liquid crystal tunable filter-factors affecting contrast ratio
Author :
Staromlynska, J.
Author_Institution :
Surveillance Res. Lab., Salisbury, SA, Australia
fDate :
2/1/1992 12:00:00 AM
Abstract :
A double-element broad-band liquid crystal tunable filter consisting of a high-order quartz wave plate in series with a very-low-order electrooptically tunable liquid crystal phase plate and placed between crossed polarizers is described. A possible application for such a device is protection against intrusive laser radiation. The advantage of this double-element filter over a single-element low-order LC filter is that it increases the wavelength resolution of the device, which, when operated in the protect mode, allows continued sensing of the scene. Experimental and theoretical studies were made of the contrast ratios obtainable with such a filter
Keywords :
electro-optical devices; liquid crystal devices; optical filters; optical polarisers; optical resolving power; tuning; contrast ratio; crossed polarizers; double-element broad-band liquid crystal tunable filter; high-order quartz wave plate; intrusive laser radiation; protect mode; scene sensing; very-low-order electrooptically tunable liquid crystal phase plate; wavelength resolution; Filters; Laser modes; Laser theory; Lasers and electrooptics; Layout; Liquid crystals; Optical retarders; Polarization; Protection; Tunable circuits and devices;
Journal_Title :
Quantum Electronics, IEEE Journal of
