Optical Filter, Spectrometric Module, And Spectral Measurement Method

A spectral measurement method using an optical filter,

• the optical filter including
• a variable wavelength interference filter including a pair of reflection films and having a plurality of transmission peak wavelengths according to a dimension of a gap between the pair of reflection films, and
• a fixed wavelength filter disposed so as to face the variable wavelength interference filter and having a plurality of filter regions different from one another in transmission wavelength segment,
• the plurality of transmission peak wavelengths of the variable wavelength interference filter corresponding to the transmission wavelength segments of the plurality of filter regions, respectively,
• the method comprising:
• a scanning step of changing the gap dimension at predetermined intervals in such a way that the plurality of transmission peak wavelengths of the variable wavelength interference filter each change within a corresponding one of the transmission wavelength segments of the plurality of filter regions;
• and
• a detection step of detecting light passing through the variable wavelength interference filter and the fixed wavelength filter for each of the filter regions during the scanning step.