Abstract
In this paper, we present an optical design of a near-infrared (at FeI 15648.5 angstroms) birefringent filter system which is used to obtain the chromatic images of the sun and measure the solar magnetic field at the Big Bear Solar Observatory (BBSO). This system consists of a prefilter, a liquid crystal analyzer, a wavelength-tunable birefringent filter and a Fabry-Perot Etalon. This system is expected to achieve a clean narrow pass band (1/8 angstroms). It can also be tuned across the spectral line to obtain line profiles of two-dimensional fields of view. During the design of the tunable near-IR birefringent filter and the test of its components, we found the value of birefringence index μ(ne-no) of calcite at spectral range near 15648.5 angstroms is very different from the value in literature. Because the birefringence index is important for the design of birefringent optical components, the birefringence index of calcite and its thermal coefficient are measured. Some test results of the four pairs of calcite plate used in the birefringent filter are presented.
Original language | English (US) |
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Pages (from-to) | 481-489 |
Number of pages | 9 |
Journal | Proceedings of SPIE - The International Society for Optical Engineering |
Volume | 4093 |
DOIs | |
State | Published - 2000 |
Event | Current Developments in Lens Design and Optical Systems Engineering - San Diego, CA, USA Duration: Aug 2 2000 → Aug 4 2000 |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering