OPTICAL FILTER TUNING APPARATUS AND AN OPTICAL FILTERING METHOD

摘要

An optical filter tuning apparatus and filtering method which uses an optical fi lter (8) that reflects light of a predetermined wavelength which is dependent on the position of incidence (16) of the light on the filter (8), and a retroreflector (32) moveable with respect to the filter (8) and which reflects light from an optical source ( 4) to the position of incidence (16) and reflects light of the predetermined wavelength from the filter (8) to an optical receiver (6).