Continuous-wave and SESAM mode-locked operation of a Yb:YSr₃(PO₄)₃ laser

We report on the continuous-wave (CW) and, for what we believe to be the first time, passively mode-locked (ML) laser operation of an Yb³⁺-doped YSr₃(PO₄)₃ crystal. Utilizing a 976-nm spatially single-mode, fiber-coupled laser diode as pump source, the Yb:YSr₃(PO₄)₃ laser delivers a maximum CW output power of 333 mW at 1045.8 nm with an optical efficiency of 55.7% and a slope efficiency of 60.9%. Employing a quartz-based Lyot filter, an impressive wavelength tuning range of 97 nm at the zero level was achieved in the CW regime, spanning from 1007 nm to 1104 nm. In the ML regime, incorporating a commercially available semiconductor saturable absorber mirror (SESAM) to initiate and maintain soliton-like pulse shaping, the Yb:YSr₃(PO₄)₃ laser generated pulses as short as 61 fs at 1062.7 nm, with an average output power of 38 mW at a repetition rate of ∼66.7 MHz.