No abstract

In this letter, an in-fiber integrated Michelson interformeteris proposed and experimentally demonstrated. The device consists in the combination of multi-mode fiber (MMF) and a single-mode fiber (SMF) tip which is covered by thick silver film. The MMF excites cladding modes into downstream SMF via the mismatch-core splicing interface. The core-cladding modes are reflected back by the silver and recoupled to fiber core through the MMF. By the reason of fiber-core mismatch and core-cladding modes interference, a well-defined interference pattern is obtained. A stable dual-wavelength fiber laser based on a hybrid gain medium combined with the interferometer filter is realized.