Spectroscopic properties of Tm3+ doped TeO2-R2O-La2O3 glasses for 1.47 μm optical amplifiers

Upon excitation at 808 nm laser diode, an intense 1.47 μm infrared fluorescence has been observed with a broad full width at half maximum (FWHM) of about 124 nm for the Tm3+-doped TeO2-K2O-La2O3 glass. The Judd–Ofelt parameters found for this glass are: Ω2 = 5.26 × 10−20 cm2, Ω4 = 1.57 × 10−20 cm2 and Ω6 = 1.44 × 10−20 cm2. The calculated emission cross-sections of the 1.47 μm transition are 3.57 × 10−21 cm2, respectively. It is noted that the gain bandwidth, σe × FWHM, of the glass is about 440 × 10−28 cm3, which is significantly higher than that in ZBLAN and Gallate glasses, a high gain of 35.5 dB at 1470 nm can be obtained in a TKL glass fiber. TeO2-R2O (R = Li, Na, K)-La2O3 glasses has been considered to be more useful as a host for broadband optical fiber amplifier.