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 Ω2 = 11.11×10⁻²⁰ cm², Ω4 = 3.5×10⁻²⁰ cm² and Ω6 = 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.