Journal Article

Study of the Optical Features of Tbsup.3+:CaYAlOsub.4 and Tbsup.3+/Prsup.3+:CaYAlOsub.4 Crystals for Visible Laser Applications

Yu, Yi, Cheng, Jian, Wang, Zhiyuan, Tu, Chaoyang, Wang, Yeqing, Gong, Yujing, Sun, Yijian, Huang, Jianhui

2022

Overview

Single crystals of Tb[sup.3+] single-doped and Tb[sup.3+]/Pr[sup.3+] co-doped CaYAlO[sub.4] were produced by the Czochralski method. The room-temperature polarized absorption spectra, emission spectra, and decay curves were recorded and analyzed in detail. The absorption cross-section around 487 nm was found to be 1.53 × 10[sup.−22] cm[sup.2] for the π polarization in the Tb[sup.3+]:CaYAlO[sub.4] crystal and increased to 5.23 × 10[sup.−22] cm[sup.2] in the Tb[sup.3+]/Pr[sup.3+]:CaYAlO[sub.4] crystal. The spectroscopic parameters were calculated through the Judd–Ofelt theory. For the Tb[sup.3+]:CaYAlO[sub.4] crystal, the emission bands of green light at 546 nm and yellow light at 587 nm had fluorescence branching ratios of 64.7% and 6.65% with cross-sections of 8.82 × 10[sup.−22] cm[sup.2] (σ-polarization) and 0.44 × 10[sup.−22] cm[sup.2] (π-polarization), respectively. The decay lifetimes of [sup.5]D[sub.4] multiplets were measured to be 1.41 ms and 1.1 ms for Tb[sup.3+]:CaYAlO[sub.4] and Tb[sup.3+]/Pr[sup.3+]:CaYAlO[sub.4] crystals, respectively. The energy transfer mechanisms of Tb[sup.3+] and Pr[sup.3+] and their emission spectral intensities at different temperatures were analyzed. As the temperature increased, the luminescence intensity of the Tb[sup.3+]:CaYAlO[sub.4] and Tb[sup.3+]/Pr[sup.3+]:CaYAlO[sub.4] crystals decreased almost linearly with the CIE coordinate variation, from (0.370, 0.621) to (0.343, 0.636) and from (0.345, 0.638) to (0.246, 0.698), respectively. The results indicate the potential of Tb[sup.3+]:CaYAlO[sub.4] and Tb[sup.3+]/Pr[sup.3+]:CaYAlO[sub.4] crystals as visible laser materials with a wide temperature range.

• Publisher: MDPI AG
• Subject: Fluorescence