Highly efficient, high-power, broadly tunable, cryogenically cooled and diode-pumped Yb:CaF2

International audienceWe present a high-power diode-pumped Yb:CaF2 laser operating at cryogenic temperature (77 K). A laser output power of 97 W at 1034 nm was extracted for a pump power of 245 W. The corresponding global extraction efficiency (versus absorbed pump power) is 65%. The laser small signal gain was found to be equal to 3.1. The laser wavelength could be tuned between 990 and 1052 nm with peaks that correspond well to the structure of the gain cross-section spectra registered at low temperature