Optical devices, wavelength tunable filter, wavelength tunable filter module, and an optical spectrum analyzer

摘要

An optical device includes a movable portion and a fixed portion having a first light reflection portion. The movable portion has a second light reflection portion facing the first light reflection portion with a first gap. The first and second light reflection portions are configured to reflect light repeatedly between the first and second light reflection portions so as to cause interference and emit light having a wavelength corresponding to a size of the first gap. The optical device also includes a first electrode portion fixed to the fixed portion so as to face a surface of the movable portion near the first light reflection portion with a second gap between the movable portion and the first electrode portion. The optical device has a second electrode portion fixed to the fixed portion so as to face another surface of the movable portion with a third gap between the movable portion and the second electrode portion. One of the first and second electrode portions serves as a detection electrode for detecting a capacitance between the movable portion and the detection electrode. Another of the first and second electrode portions serves as a drive electrode. The optical device includes a circuit operable to generate a potential difference between the movable portion and the drive electrode so as to generate an electrostatic attraction force therebetween for changing a position and/or a posture of the movable portion.