Switchable and wavelength interval adjustable multi-wavelength actively Q-switched fiber laser based on EOM and improved Lyot filter

A switchable and wavelength interval adjustable multi-wavelength erbium-doped fiber actively Q-switched fiber laser based on EOM and improved Lyot filter is proposed. In the experiment, stable and switchable laser outputs of single to quintuple-wavelength can be achieved by adjusting the polarization controllers and the wavelength intervals are adjustable between 2 nm, 3 nm and 6 nm. With the increase of the pump power, the number of output wavelength reaches nine. Moreover, the single-dual and dual-pulse sequences can be observed in a modulation period and the dual-pulse interval can be tuned from 14.7 to 11.1 µs. The wavelength interval of the proposed laser and the pulse interval of the dual-pulse can be adjusted more flexibly. It has a broad application prospect in the fields of optical measurement and laser imaging.