  Multi-wavelength fiber lasers have emerged as a promising light source for
the application in wavelength division multiplexing communication, terahertz
wave generation and optical sensing due to high efficiency and robustness.
Lyot-filter emerges as a potential device for multi-wavelength generation
application. However, because of the high birefringence of polarization
maintaining fiber in Lyot-filter, it is difficult to generate broadband
dual-wavelength or multi-wavelength mode-locked fiber laser by using common
Lyot-filter. In this paper, for the first time, we propose an idea of using the
low birefringence induced by bending the single-mode fiber to form a
Lyot-filter for dual-wavelength mode-locked fiber laser generation. The
dual-wavelength output centers at 1532 and 1556 nm and it may simplify the
set-up for dual-wavelength mode-locked laser.
