2.0 μm Ultra Broadband Emission from Tm3+/Ho3+ Co-Doped Gallium Tellurite Glasses for Broadband Light Sources and Tunable Fiber Lasers

作者：Yuan, Jian^*; Wang, Weichao; Ye, Yichen; Deng, Tingting; Huang, Yizhao; Gu, Shitao; Chen, Yuanbin; Xiao, Peng

来源：Crystals, 2021, 11(2): 190.

DOI：10.3390/cryst11020190

• gallium tellurite glass
• Tm3+/Ho3+ co-doped
• 2.0 mu m ultra broadband emission
• energy transfer
• tunable fiber laser

A flat 2.0 mu m ultra broadband emission with a full width at half maximum (FWHM) of 329 nm is achieved in 1 mol.% Tm2O3 and 0.05 mol.% Ho2O3 co-doped gallium tellurite glasses upon the excitation of an 808 nm laser diode. The influence of Tm3+ and Ho3+ contents on 2.0 mu m spectroscopic properties of gallium tellurite glasses is minutely investigated by absorption spectra, emission spectra, and lifetime measurement. In addition, emission cross section and gain coefficient of Ho3+ ions at 2.0 mu m are calculated, and the maximum values reach 8.2 x 10(-21) cm(2) and 1.54 cm(-1), respectively. Moreover, forward and backward energy transfer probability between Tm3+ and Ho3+ ions are qualitatively evaluated by the extended spectral overlap method. Large ratio of the forward energy transfer from Tm3+ to Ho3+ to the backward one (19.7) and high forward energy transfer coefficient (6.22 x 10(39) cm(6)/s) are responsible for effective 2.0 mu m emission from Ho3+ ions. These results manifest that Tm3+/Ho3+ co-doped gallium tellurite glass is suitable for potential applications of broadband light sources and tunable fiber lasers operating in eye-safe 2.0 mu m spectral region.

• 单位
  佛山科学技术学院