Crystal growth, spectroscopy and first laser operation of a novel disordered tetragonal Tm:Na2La4(WO4)7tungstate crystal

Identifier:  imarina:3996506

Handle: https://hdl.handle.net/20.500.11797/imarina3996506

Authors:  Zhang, LZ; Sun, SJ; Lin, ZB; Lin, HF; Zhang, G; Mateos, X; Serres, JM; Aguiló, M; Díaz, F; Loiko, P; Wang, YC; Griebner, U; Petrov, V; Vilejshikova, E; Chen, WD

Abstract:
© 2018 Elsevier B.V. Tm3+:Na2La4(WO4)7, a disordered tetragonal scheelite-type tungstate crystal, is grown by the Czochralski method. The polarized absorption, stimulated-emission and gain cross-section spectra are determined. The maximum σSEis 1.62 × 10–20cm2at 1788.6 nm for σ-polarization. The Judd-Ofelt parameters for Tm3+are Ω2= 10.321, Ω4= 0.183 and Ω6= 2.122 [10–20cm2]. The radiative lifetime of the3F4state is 1.63 ms. Raman spectroscopy reveals a maximum phonon energy of 923 cm−1. Laser operation under diode-pumping is achieved with both a-cut and c-cut Tm:Na2La4(WO4)7crystals, reaching a maximum output power for the a-cut of 715 mW at ~ 1937 nm with a slope efficiency of 34%. Microchip laser operation using the c-cut crystal yields a slope efficiency of 41%. The Tm:Na2La4(WO4)7crystal is promising for mode-locked lasers due to its broadband emission.