Optical spectra of Tm3+ doped NaBi(WO4)2

Tm doped NaBi(WO4)2 of good optical quality with sizes of about 20 mm × 20 mm × 40 mm was grown successfully by the Czochralski technique. The absorption spectra for both σ- and π-polarizations were recorded at room temperature. Based upon these data, the oscillator strengths and radiative transition rates were evaluated. The σ- and π-polarized emission spectra together with the fluorescence decay curve were also obtained. The emission cross-section of the potential laser transition at 1460 nm was determined to be 1.49 × 10−19 cm2. The results show that Tm3+:NaBi(WO4)2 crystal is a promising laser material.