Yb~(3+)-doped YVO_(4) crystal for efficient Kerr-lens mode locking in solid-state lasers

摘要

We report the first demonstration, to our knowledge, of soft-aperture Kerr-lens mode locking in a diodepumped femtosecond Yb~(3+):YVO_(4) laser. Near-transform-limited pulses as short as 61 fs are generated around a center wavelength of 1050 nm with an output power of 54 mW and a pulse repetition frequency of 104.5 MHz. This is, to our knowledge, the shortest pulse generated directly from an Yb laser having a crystalline host material. The femtosecond operation has a mode-locking threshold at an absorbed pump power of 190 mW. The nonlinear refractive indexes of the Yb~(3+):YVO_(4) crystal have been measured to be 19 X 10~(-16) cm~(2)/W and 15 X 10~(-16) cm~(2)/W for the sigma and pi polarizations, respectively, at 1080 nm.