A sensor device is formed from a metal film having a plurality of
openings, a sensor material positioned within each of the openings, a
light source that emits light having a first wavelength, and a light
detector that detects light emitted from the light source and transmitted
through or reflected from the openings. The plurality of openings are
arranged periodically in a first direction in the metal film, and both a
size of each of the plurality of openings and an interval thereof in the
first direction are equal to or less than the wavelength of the light.