Diffractive optical modulator and method for producing the same, infrared sensor including such a diffractive optical modulator and method for producing the same, and display device including such a diffractive optical modulator

An infrared sensor comprising:

• a lens for converging infrared light and a pyroelectric element,
• wherein a diffractive optical modulator for receiving the infrared light converged by the lens and for outputting at least a part of the infrared light toward the pyroelectric element is further provided,
• the diffractive optical modulator comprising:
• a plate having a portion functioning as a first electrode;
• a spacer layer formed on the plate;
• and
• a grating consisting of a plurality of beams having a portion functioning as a second electrode, both ends of the beams being supported on the spacer layer;
• wherein, by adjusting a voltage applied between the first electrode and the second electrode, a distance between the beams and the plate is varied, thereby controlling the diffraction efficiency of the diffractive optical modulator,
• wherein an amount of zero-order diffracted light is varied in accordance with a variation of a distance between the beams and the plate of the diffractive optical modulator, and
• wherein the plate is disposed being inclined so that a normal with respect to a principal plane of the plate is not parallel to an optical axis of the lens.