<title>Plastic Birefringent Filters And System Applications</title>

Abstract

Using the Lockheed. Alternate Partial Polarizer Universal Filter technique, we have designed and built a tunable wideband birefringent filter that is all plastic. The plastics are polyvinyl alcohol and plastic polarizer. Using lamination techniques a 60 Å bandpass tunable filter has been constructed. The filter operates from 4200-8000 Å. A single knob tunes the filter by rotating po1arizers. Clear apertures of 10 to 30 cm can be constructed, with plastic filters. The cone angle can be 60° . The design, characteristics, and applications of these plastic filters are presented below.