Fiber-based dynamically tunable Lyot filter for dual-wavelength and tunable single-wavelength mode-locking of fiber lasers.

We propose and demonstrate a novel dynamically tunable fiber-based Lyot filter for the realization of a dual-wavelength mode-locked fiber laser, operating at center wavelengths of 1535 nm and 1564 nm. The same laser cavity can also be operated in a single-wavelength mode-locked regime with a wavelength tuning range of 30 nm, from 1532 nm to 1562 nm. The proposed dynamically tunable Lyot-filter provides a simple setup for laser mode-locking using a single laser cavity design to generate dual-wavelength pulses, with the flexibility to also allow the generation of single-wavelength pulses with a continuously-tunable center wavelength.