VARIABLE OPTICAL FILTER DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a variable optical filter device which is capable of correcting a transmission central wavelength at a high speed by controlling the transmission position of a light beam and is capable of executing a wavelength spectral analysis at a high speed with a high like lihood ratio at a wide range. SOLUTION: The variable optical filter device, which changes in the central wavelength of the transmitted light transmitted through the variable optical filter 2 of a disk type rotatable around a central axis by an estimated angle θfor the rotation of a transmission position, has a sweep mechanism 30 which sweeps the transmission central wavelength λc over a wide range by largely changing the angle θ at which the light passes and a correction mechanism 40 which controls the transmission central wavelength at a high speed within a limited wavelength range. The correction mechanism 40 is controlled according to a correction quantity σx determined according to the rotating angle by this sweep mechanism 30, by which the desired transmission central wavelength λc is made strictly coincident with the transmission central wavelength determined by the time.