Tunable and switchable multi-wavelength actively Q-switched random fiber laser based on an electro-optic modulator and Sagnac loop filter.

In this article, an actively Q-switched multi-wavelength random fiber laser based on a Sagnac loop filter and electro-optic modulator is proposed and demonstrated experimentally. The random distributed feedback media is a section of a 25 km long single-mode fiber. When the pump power is 350 mW, the polarization angle of the Sagnac loop filter can be adjusted by polarization controller to achieve the switching of a single, double, triple, and quadruple channels laser output.

Tunable and switchable multi-wavelength pulsed fiber laser based on a nonlinear optical loop mirror and an improved Sagnac filter.

We propose and experimentally demonstrate a tunable and switchable multi-wavelength erbium-doped fiber ring pulsed laser based on a nonlinear optical loop mirror (NOLM) and an improved Sagnac filter. To achieve multi-wavelength pulsed laser output, we adopt a NOLM as a quasi-saturable absorber and an improved Sagnac loop as a wavelength selected filter. The constructed laser has a maximum output wavelength number of five with a pulse repetition frequency of 40.