TUNABLE INTERFERENCE FILTER, OPTICAL MODULE, AND PHOTOMETRIC ANALYZER

摘要

An etalon as a tunable interference filter includes a first substrate, a second substrate, a fixed mirror, a movable mirror, and an electrostatic actuator. The respective mirrors are formed by stacking one layer of a TiO2 film and one layer of an alloy film. A film thickness dimension of the TiO2 film and a film thickness dimension of the Ag alloy film are set to film thicknesses such that reflectance of a reference wavelength may be target reflectance and reflectance of a set wavelength may be lower than that of the case where the reflection film is formed only by the metal film.