Self-sweeping Tm-doped fiber laser with wavelength stopping

We demonstrate a Tm-doped fiber laser which operates in three self-sweeping regimes, depending on pump power: (1) a single-frequency self-sweeping operation with a normal scanning direction; (2) a multi-frequency operation with a reverse direction, and; (3) wavelength stopping. In the last case, the wavelength can be stopped at an arbitrary value in the range from 1912 nm to 1923 nm, depending on the prehistory of spectral dynamics of the laser. The wavelength fluctuations in the case of wavelength stopping are below our measurement resolution of 50 pm within 5 min. As a result, we have manually controlled the laser wavelength with pump power adjustment. This result can extend the potential practical applications of self-sweeping lasers.