Optical filter device and method for controlling optical filter device

An optical filter device comprising:

• a Fabry-Perot interference filter;
• and
• a first external terminal, a second external terminal, and a third external terminal electrically connected to the Fabry-Perot interference filter,
• wherein the Fabry-Perot interference filter comprises:
• a first structural body having a first surface and a second surface opposite the first surface;
• a second structural body having a third surface facing the first surface via an air gap;
• a first mirror portion provided to the first structural body;
• a second mirror portion provided to the second structural body so as to face the first mirror portion via the air gap, a distance between the first mirror portion and the second mirror portion in a light transmission region being adjusted;
• a first driving electrode provided to the first structural body;
• a second driving electrode provided to the second structural body so as to face the first driving electrode via the air gap;
• a first terminal electrically connected to the first driving electrode;
• a second terminal electrically connected to the second driving electrode;
• and
• a third terminal electrically connected to the first driving electrode
• wherein the first driving electrode overlaps the air gap when viewed from a facing direction in which the first surface and the third surface face each other,
• a distance between the first driving electrode and the air gap in the facing direction is shorter than a distance between the second surface and the air gap in the facing direction,
• the first external terminal is electrically connected to the first terminal,
• the second external terminal is electrically connected to the second terminal, and
• the third external terminal is electrically connected to the third terminal.

A method for controlling an optical filter device including a Fabry-Perot interference filter, the Fabry-Perot interference filter comprising:

• a first structural body having a first surface and a second surface opposite the first surface;
• a second structural body having a third surface facing the first surface via an air gap;
• a first mirror portion provided to the first structural body;
• a second mirror portion provided to the second structural body so as to face the first mirror portion via the air gap, a distance between the first mirror portion and the second mirror portion in a light transmission region being adjusted;
• a first driving electrode provided to the first structural body;
• a second driving electrode provided to the second structural body so as to face the first driving electrode via the air gap;
• a first terminal electrically connected to the first driving electrode;
• a second terminal electrically connected to the second driving electrode;
• and
• a third terminal electrically connected to the first driving electrode
• wherein the first driving electrode overlaps the air gap when viewed from a facing direction in which the first surface and the third surface face each other, and
• a distance between the first driving electrode and the air gap in the facing direction is shorter than a distance between the second surface and the air gap in the facing direction,
• the method for controlling the optical filter device comprising:
• a first step of measuring a resistance value of the first driving electrode via the first terminal and the third terminal;
• and
• a second step of adjusting a voltage or a current applied between the first terminal and the second terminal based on the resistance value measured in the first step.