Radiative Transitions and Optical Behaviors in Tm3+ Doped Mixed Alkali/Alkaline-Earth Modified Heavy-Metal Gallate Glasses

Abstract

Efficient ~1.48 and ~1.8mm infrared emissions have been recorded in Tm3+doped mixed alkali/alkaline-earth modified heavy-metal gallate glasses (LKBPBG) with low phonon energy under 793nm excitation. Judd-Ofelt parameters W2(4.34´10-20cm2), W4(9.74´10-21cm2) and W6(1.00´10-20cm2) indicate a higher asymmetric and stronger covalent environment in the glass material. The spontaneous transition probability and maximum emission cross-section of3H4→3F4transition are derived to be 283s-1and 2.90´10-21cm2. The maximum emission cross-section of3F4→3H6transition is calculated to be 6.82´10-21cm2, and the ideal net gain coefficients at 1.675 (U-band edge) and 1.872mm are given to be 0.56 and 3.51dB/cm, respectively, as the population inversion equals 1.0, which provide a theoretical anticipation in developing U-band amplifiers and eye-safe medical lasers.