Patent ID: 7483211

Claim:
An optical tunable filter comprising: a fixed substrate having a first recess formed therein; a movable substrate bonded to said fixed substrate, said movable substrate including a movable portion having an opening formed at a location facing said first recess and a support portion for supporting said movable portion so that said movable portion can be displaced; a light-transmittable substrate bonded to said movable portion at a location near said opening; a fixed reflection film formed on a bottom of said first recess; a movable reflection film formed on a surface of said light-transmittable substrate which faces said first recess; an interference gap formed between said fixed reflection film and said movable reflection film for causing interference of light due to repeated reflection between said fixed reflection film and said movable reflection film; and an actuator operable to displace said movable portion relative to said fixed substrate to vary a size of said interference gap for emitting light having a wavelength corresponding to the size of said interference gap to an exterior of said optical tunable filter.