ETALON AND METHOD FOR PRODUCING ETALON

摘要

This etalon (1) has: 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 a 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).