OPTICAL MATERIAL, OPTICAL DEVICE, AND ETALON

摘要

PROBLEM TO BE SOLVED: To provide an optical material which has a low manufacturing cost, undergoes little change in the direction of a ray even when it has a temperature unevenness, has excellent transmittance to infrared rays, and has controlled temperature dependency of an optical path length, to provide an optical device, and to provide an etalon. SOLUTION: The optical material comprises a crystallized glass in which the main crystal is a deposition of aβ-quartz solid solution or aβ-eucryptite solid solution, has an infrared transmittance of at least 50% in a thickness of 3 mm at any one of wavelengths in the range of 1,200 to 1,700 nm, has a coefficient of thermal expansionαof -2.0×10-6to 2.0×10-6/°C at -40 to 100°C, and satisfies the relationship:ϕ-0.5α<19.5×10-6(whereinαis the coefficient of thermal expansion, andϕis the temperature coefficient of polarizability). COPYRIGHT: (C)2006,JPO&NCIPI