Diode-pumped mode-locked Yb:YScO laser.

To the best of our knowledge, we report on the mode-locking of the mixed sesquioxide single crystal Yb:YScO for the first time. The spectra of Yb ions in this crystal were studied at both room temperature and low temperature. A continuous-wave laser output at 1080 nm was achieved using a fiber-coupled semiconductor laser, with a pump wavelength of 976 nm, in the Yb:YScO crystal, yielding a maximum output power of 7.45 W and a slope efficiency of 52.3%. By implementing a SESAM for initiating and stabilizing the mode-locked operation, the Yb:YScO laser produced soliton pulses as short as 48 fs at 1056.4 nm, with an average output power of 45 mW at a pulse repetition rate of ∼ 71.55 MHz. These results suggest that Yb:YScO crystals are promising candidates for high-power ultrashort pulse lasers.