Structure, spectroscopy and laser operation at ∼ 2.8 μm of a novel Er:SGGG crystal

We demonstrate the crystal structure, spectroscopy and laser performance of a novel Er:SGGG crystal grown successfully by Czochralski (Cz) method. The lattice constant is refined to be 12.42 Å and the FWHM of the crystal’s X-ray rocking curve is only 86.4″, indicating an excellent quality. The segregation coefficient of Er³⁺ ions in SGGG is determined to be 1.2. The Er:SGGG crystal displays a specialty in broadening spectrum. There is a wide absorption band near 962 nm, with an absorption bandwidth of 19 nm and a peak absorption coefficient of 5.57 cm⁻¹. Under the conditions of 969 nm laser diode (LD) pumping, with a 400 Hz repetition rate and 300 μs pulse duration, a maximum power 404 mW with slope efficiency of 15.6 % at 2.8 μm is achieved on the Er:SGGG crystal. The M² factors of horizontal and vertical are 1.4 and 1.5, respectively. The results indicate the mid-infrared laser output can be generated in the Er:SGGG crystal, and it is a potential and promising candidate for 2.8 μm laser material.