Spectral and laser performance of a Tm3+:ScYSiO5 crystal

Spectroscopic features and laser performance of a novel thulium-doped scandium yttrium silicate crystal Tm3+:ScYSiO5 (Tm:SYSO) are presented. The experimental lifetime of luminescence related to the 3F4 - 3H6 laser transition of Tm3+ amounts to 1.1 ms, which is smaller by a factor of three than the calculated radiative lifetime value due to the contribution of nonradiative relaxation. As a consequence of the internal disordered structure of the SYSO host crystal, the luminescence bands of 3F4 - 3H6 and 3H4 - 3H6 show significant inhomogeneous spectral broadening as compared with that of SSO. The laser performances were evaluated in an end-pumped cavity using a CW semiconductor laser as a pump source. In a free run regime, the Tm:SYSO laser delivered a maximum output power of 580 mW at 2022 nm, corresponding to a slope efficiency of 17.4%. With a birefringent quartz plate inserted into laser cavity, the laser output wavelength was continuously tuned from 1950 nm to 2057 nm and dual wavelength operations at 2011 nm and 2020 nm, 1987 nm and 2045 nm, 2022 nm and 2044 nm were observed.