Optical wavelength tunable filter

摘要

The wavelength tunable optical filter (1) comprises a resonant cavity (4) delimited by two opposite reflective elements (8, 8') which are not wavelength selective, and a reflector (7) external to the cavity (4). The external reflector (7) exhibits transmission peaks for an integer number N of optical frequencies and the Fabry-Perot cavity (4) delimiting a phase tuning section (11) is sized so that the distance between the optical frequencies of any two resonant modes of the cavity (4) is never equal to the difference between the optical frequencies of any two transmission peaks of the external reflector (7).