High average power 80 MHz repetition rate additive pulse mode-locked femtosecond Yb:YAG laser

Summary form only given. In this paper we report on an additive-pulse-mode-locked Yb:YAG laser which generates high average power fs-laser pulses with a repetition rate of 80 MHz. For pumping we use a fiber coupled diode laser which emits 20 W of 940 nm light out of a fiber with 200 /spl mu/m core diameter. The pump light is focused into a Yb:YAG rod to a spot size of 200 /spl mu/m. To improve the homogeneity of the pump light distribution inside the laser crystal, the transmitted pump-light is reflected back into the crystal.