Yb:CaF2 laser at cryogenic temperature

The authors present the first laser operation of a singly doped Yb:CaF₂ at cryogenic temperature and high power level. The laser shows very interesting properties: a laser efficiency up to 70 %, an output power approaching 100 W at 1034 nm with an incident pump power of 212W, a small signal gain exceeding 3, a laser wavelength tunability compatible with femtosecond pulse amplification. Moreover in this first experiment we have demonstrated the laser emission at 992 nm despite the presence of high-loss (at this wavelength) dichroic mirror, which is very encouraging for the potential of a natural ultra-low quantum defect laser very appropriate for high power DPSSL development.