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

Upon excitation at 808nm laser diode, an intense 1.47 mu m infrared fluorescence has been observed with a broad full width at half maximum (FWHM) of about 124nm for the Tm3+-doped TeO2-K2O-La2O3 glass. The Judd-Ofelt parameters found for this glass are: Omega 2 =5.26x10 super(-20) cm2, Omega 4 =1.57x10 super(-20) cm2 and Omega 6 =1.44x10 super(-20) cm2. The calculated emission cross-sections of the 1.47 mu m transition are 3.57x10 super(-21) cm2, respectively. It is noted that the gain bandwidth, Iefe A-FWHM, of the glass is about 440x10 super(-28) cm3, which is significantly higher than that in ZBLAN and Gallate glasses, a high gain of 35.5dB at 1470nm 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.