Polarization switching and optical bistability in the diode-pumped Tm,Ho:LLF laser

We first report on the polarization switching and optical bistability in the Tm,Ho:LLF laser. In the free-running operation, the switching of the π-polarization at 2069 nm and σ-polarization at 2066 nm are experimentally observed. By adjusting the tilting angle of an intracavity etalon, the orthogonally polarized dual-wavelength single-longitudinal-mode laser is obtained at 2054 and 2066 nm, and the π-polarized and σ-polarized single wavelength single-longitudinal-mode laser is obtained at 2057 and 2063 nm, which all show evident optical bistability.