Near-infrared luminescence of Er3+ doped Na0.04K0.96Y(WO4)2 single crystals

Single crystals of the compositions Na0.04K0.96Y(WO4)(2) (NKYW) and x mol% Er: Na0.04K0.96Y(WO4)(2 )(x = 1, 3, 5, 7) (Er: NKYW) have been successfully grown by the top-seeded solution growth (TSSG) method. The growth process parameters have been investigated in detail. X-ray diffraction (XRD) and Raman spectroscopy measurements showed that the K+ and Na+ cations occupied equivalent lattice sites and the crystal structure remained monoclinic. The spectral properties and energy transfer mechanisms of the single crystals doped with different concentrations of Er3+ ions were investigated. According to the Judd-Ofelt theory, the intensity parameters of the 5 mol% Er: NKYW crystal were calculated to be omega(2) = 1.77 x 10(-20) cm(2), omega(4) = 3.15 x 10(-20) cm(2), omega(6) = 3.08 x 10(-20) cm(2), and the radiative transition probability of I-4(13/2) -> I-4(15/2) was 541.25 s(-1). The gain cross section of the 5 mol% Er: NKYW crystal at 1542 nm was determined to be 2.63 x 10(-20) cm(2), indicating that high quality Er: NKYW single crystals have great potential for laser applications.