Spectroscopic and 1.5–1.6 μm laser properties of Er:Yb:GdSr3(PO4)3 crystal

Abstract

An Er:Yb:GdSr3(PO4)3 crystal was grown by the Czochralski method, and its spectroscopic properties were investigated at room temperature. The peak absorption cross section is 1.12 × 10−20 cm2 at 975 nm and the full width at half maximum of the absorption band is 5.8 nm. The peak emission cross section is 0.74 × 10−20 cm2 at 1535 nm and the full width at half maximum of the fluorescence band is 41 nm. Fluorescence lifetime of the 4I13/2 multiplet of Er3+ and Yb3+→Er3+ energy transfer efficiency in the crystal are 7.97 ms and 91.8 %, respectively. End-pumped by a 975 nm diode laser, a 1563 nm continuous-wave laser with a maximum output power of 60 mW and a slope efficiency of 16.1 % was realized in an Er:Yb:GdSr3(PO4)3 crystal at an absorbed pump power of 413 mW. Using a SiO2 birefringent filter as a wavelength tuning element, a continuously tunable 1.5–1.6 μm laser with a range of 45 nm and a maximum output power of 30 mW at 1541 nm was obtained at the same pump power.