Spectroscopic study of bismuth-doped silica glass

In this paper we investigate the spectroscopic performance of bismuth-doped silica glass at temperature from 10 K to room temperature to identify the nature of the luminescent centre and to understand its fluorescence dynamics. Performing low temperature measurements we show that the near infrared luminescence spread over at least three emission bands centered at 1050, 1260 and 1430 nm when pumped in the region 700-850 nm whereas it consists in one main luminescence peak at 1140 nm when excited at 500 or 1000 nm. The relative intensity of these bands depends on the excitation wavelength. The richness of the energy level organisation is confirmed by the observation of green up-conversion emission when the sample is excited around 800 nm.