Green luminescence of Er3+ in stoichiometric KYb(WO4)2 single crystals

We grew good-optical-quality KYb(WO4)2 single crystals doped with erbium ions by the top seeded solution growth slow cooling method. Optical absorption of erbium was performed at room temperature (RT) and at 6 K. Green photoluminescence of erbium was achieved at RT and 6 K after selective excitation of ytterbium ions at 940 nm (10 638 cm−1). The splitting of all found excited energy levels and the ground energy level of erbium in KYb(WO4)2 is presented derived from the accurate absorption and emission measurements, respectively. The lifetime of the Stokes and the anti-Stokes green emissions of erbium were measured after excitation at 488 nm (20 490 cm−1) and 940 nm(10 638 cm−1), respectively. We propose applying the up-conversion model to the observed green emission.