Tunable and Switchable Multi-Wavelength Erbium-Doped Fiber Laser Based on Composite Structure Filter

A multi-wavelength erbium-doped fiber laser (MW-EDFL) with wide tuning range, switching and adjustable wavelength interval is designed tested, which based on a composite filter. The filter consists of tapered microfiber coupler loop (TMCL) nested single mode (SMF)-two (TMF)-SMF (STS) structure, has comb spectrum obvious envelope uniform fluctuation. Our experimental theoretical results show that the can output thirteen wavelengths, when angles two polarization controllers (PCs) in TMCL are accurately set. Moreover, by adjusting PCs, range single- to sextuple-wavelength reach about 40 nm. Six non-adjacent outputs be observed some specific states. maximum side-mode suppression ratio (SMSR) 40.6 dB. Compared other EDFL, characteristics laser, such as adjustability flexibility spacing switch-ability number, have been improved.