HIGH SPEED WAVELENGTH DISCRIMINATING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a high-speed wavelength discriminating mechanism by removing the limit on a mechanical mechanism by providing a disk type optical filter having a filter characteristic in which the transmitting central wavelength is changed along the circumferential direction and a means for rotating the optical filter at high speed synchronized with an external signal. SOLUTION: This device is provided with a disk type optical filter 12 arranged in the optical path 11 of collimated light and having a filter characteristic whose transmitting central wavelength is changed in the circumferential direction and a variable rotating mechanism 13 as a means for rotating the optical filter 12 at high speed sybchronized with an external signal. In this case, in order to remove the mechanical restriction on the maximum number of revolution, a disk rotating mechanism is adopted as the variable rotating mechanism 13. A filter layer 15 whose central wavelength is changed in the circumferential direction is provided on a quartz disk 14 as the substrate composing the disk type optical filter 12, the filter layer 15 is composed of an ordinary dielectric multilayer film and the central wavelength is continuously changed over a wide band.