Fabry-Perot filter, wavelength-selective infrared detector and infrared gas analyzer using the filter and detector

摘要

A Fabry-Perot filter device for selectively transmitting three wavelength bands of infrared radiation, including a reference light band, wherein the filter device comprises a fixed mirror formed on a substrate; a movable mirror arranged opposite to the fixed mirror with a gap formed therebetween so that the movable mirror is displaced with respect to the fixed mirror by applying an external force; a fixed electrode formed on the fixed mirror; and a movable electrode formed on the movable mirror and arranged opposite to the fixed electrode wherein the movable electrode is displaced by applying a potential difference across the fixed and movable electrodes so that the width of the gap is varied in at least three steps, whereby at least three wavelength bands of infrared radiation are selectively transmitted through the filter device.