ETALON AND METHOD FOR PRODUCING ETALON

摘要

PROBLEM TO BE SOLVED: To provide a new type of etalon.SOLUTION: An etalon 1 includes: a first translucent body 7A of which the change in light path length with respect to a temperature increase change is positive; a second translucent body 7B of which the change in light path length with respect to the temperature increase change is negative; a first reflecting film 5A covering a first outer surface 51A; a first anti-reflection film 9A covering a first inner surface 55A; a second anti-reflection film 9B covering a second inner surface 55B; and a second reflective film 5B covering the first outer surface 51A. The first inner surface 55A and the second inner surface 55B face each other sandwiching a gap 53.