The Birefringent Filter
Abstract
The basic principles of birefringent filter operation are briefly discussed and references given to papers which discuss the theory. Off-axis effects are investigated as well as field of view limitations, and methods for extending the field of view are considered. The split element filter is described; it uses only half as many polarizers as a conventional filter, after the first polarization. Wave length adjustment possibilities are evaluated for conventional and split element filters. The usefulness of various crystal materials is mentioned. Finally, the polarization interferometer is discussed as a way of accomplishing the narrow-band transmission of an impossibly thick birefringent filter element. Several possible forms of interferometer are mentioned.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1948
- Accession Number
- AD0740709
Entities
People
- John W. Evans
- Walter O. Roberts
Organizations
- High Altitude Observatory