Variable wavelength interference filter, optical filter device, optical module, and electronic apparatus

摘要

A variable wavelength interference filter includes a stationary substrate, a movable substrate bonded to the stationary substrate, a stationary reflecting film provided to the stationary substrate, a movable reflecting film provided to the movable substrate, and opposed to the stationary reflecting film across an inter-reflecting film gap, and an electrostatic actuator adapted to vary the gap amount of the inter-reflecting film gap by deflecting the movable substrate toward the stationary substrate, a releasing space to which air between the stationary reflecting film and the movable reflecting film moves when the gap amount of the inter-reflecting film gap is reduced is provided between the stationary substrate and the movable substrate, and assuming that a spring constant of the movable substrate is kv, and a spring constant of the air existing in the inter-reflecting film gap is kair, kv≧20×kair is satisfied.

主权项

1. A variable wavelength interference filter comprising:
a first substrate; a second substrate opposed to the first substrate, the second substrate being bonded to the first substrate; a first reflecting film provided to the first substrate; a second reflecting film provided to the second substrate, the second reflecting film being opposed to the first reflecting film across an inter-reflecting film gap having a predetermined gap amount; and a gap amount changing section adapted to vary the gap amount of the inter-reflecting film gap by moving the second substrate relative to the first substrate, wherein a releasing space, to which gas between the first reflecting film and the second reflecting film moves when the second substrate moves closer to the first substrate due to the gap amount changing section, is provided between the first substrate and the second substrate, the releasing space being in communication with an exterior of the filter through an extraction electrode groove formed in the first substrate that extends outward from the releasing space, and an air spring constant of the gas between the first reflecting film and the second reflecting film is kair, and a spring constant of the second substrate is kv, the following relationship is satisfied:
kv≧20×kair.