A SPECTROSCOPIC STUDY OF THE BEST PUMP WAVELENGTH IN THE 800 NM BAND FOR ERBIUM-DOPED FLUOROZIRCONATE FIBER AMPLIFIERS

The fluorescence spectrum of erbium-doped fluorozirconate glass was investigated with a tunable Ti-sapphire laser source operating in the 800 nm band. It was found that the green fluorescence (comprised of the 524 nm and 546 nm bands), which was due to pump excited state absorption, was always present along with the useful 1550 nm fluorescence band. However, the intensity of the 1550 nm signal was found to reach a maximum and the intensity ratio of the 1550 nm and 546 nm signals were also approaching a maximum when excited with the 801 nm wavelength. This was therefore considered to be a favourable pump wavelength for erbium-doped fluorozirconate fibre amplifiers.