All-fiber Michelson-Gires-Toumois interferometer as multi-passband filter

In this paper, we present a novel flattop multi-passband filter based on all-fiber Michelson-Gires-Tournois interferometer (MGTI). With introducing a distributed Gires-Tournoise etalon to a Michelson interferometer, we realize, for the first time to our knowledge, an all-fiber MGTI structure. Compared with the bulk-optic MGTI, the proposed all-fiber device has some additional advantages such as fully compatible with fiber system, low insertion loss and low cost. Such filters are potentially very attractive for DWDM application in optical fiber communication systems.