Near-infrared emissions and quantum efficiencies in TM3+-doped heavy metal gallate glasses for S- and U-band amplifiers and 1.8 mu m infrared laser

摘要

Intense 1.8 mu m and efficient 1.48 mu m infrared emissions have been recorded in Tm3+-doped alkali-barium-bismuth-gallate (LKBBG) glasses with low phonon energies under the excitation of 792 nm diode laser. The maximum emission cross-sections for 1.8 and 1.48 mu m emission bands are derived to be 6.26 x 10(-21) and 3.34 x 10(-21) cm(2), respectively, and the peak values are much higher than those in Tin(3+)-doped ZBLAN glass. In low-concentration doping, the full-widths at half-maximum (FWHMs) of the two emission bands are 223 and 122 nm, and the quantum efficiencies of the F-3(4) and H-3(4) levels are proved to be similar to 100 and 86, respectively. When the doping concentration increases to 1 wt, the quantum efficiency of the H-3(4) level is reduced to 60 due to the cross-relaxation processes in high-concentration doping. Efficient 1.8 pm infrared emission in Er3+/Tm3+-codoped LKBBG glass has also been achieved under the excitation of 970 nin diode laser, and the probability and the efficiency of non-radiative energy transfer from Er3+ to Tm3+ are as high as 354 s(-1) and 58.4, respectively. Efficient and broad 1.8 and 1.48 mu m infrared emission bands indicate that Tm3+-doped LKBBG glasses are suitable materials in developing S- and U-band amplifiers and 1.8 Pin infrared laser. (C) 2007 Elsevier B.V. All rights reserved.