Qingjie Huang

Optical parameters and upconversion fluorescence in Tm3+/Yb3+ codoped tellurite glass

Tm3+/Yb3+ codoped tellurite glass has been prepared. Density, refractive index, optical absorption, Judd-Ofelt parameters and spontaneous transition probabilities of Tm3+ have been measured and calculated, respectively. Intense blue three-photon upconversion fluorescence and S-band (1470 nm) fluorescence were investigated under the excitation of a 980 nm diode laser at room temperature. Judd-Ofelt parameters, strong blue three-photon upcoversion emission of Tm3+ in glass indicate that Tm3+/Yb3+ codoped tellurite glass is a promising blue color upconversion optical and laser material. In addition, experiment results showed the 980 nm laser was more efficient than 808 nm laser when pumping Tm3+/Yb3+ codoped tellurite glass, Tm3+/Yb3+ codoped tellurite glass also could be a promising material for S-band amplification.

Spectroscopic properties of Tm3+ ions in Tm3+/Yb3+ codoped tellurite glass

Absorption coefficience of Tm³⁺ ions in Tm³⁺/Yb³⁺ codoped tellurite glass have been analyzed by using the J-O theory. The J-O parameters are calculated to be Ω<inf>2</inf> = 11.11×10⁻²⁰ cm², Ω<inf>4</inf> = 3.5×10⁻²⁰ cm² and Ω<inf>6</inf> = 3.6×10⁻²⁰ cm². Spontaneous radiative transition probabilities, branching ratios and radiative life time of Tm³⁺ ions are also calculated, the calculation results indicate that it is difficult to get S-band amplification through single 808 nm laser pump in this glass, this is tested by 808 nm single wavelength pump experiment. The Yb³⁺ codoping with Tm³⁺ and energy transfer process between them make 980 nm single wavelength pump scheme possible to get S-band amplification, experiment results indicate that 980 nm pump energy absorbed by Yb³⁺ is transferred to Tm³⁺, consequently, the low cost 980 nm pump scheme could make it become promising material for S-band amplification.