Multiphoton process and optical amplification in Er~(3+)-Yb~(3+)-doped fiber pumped by Ti:Al_2O_3 tunable laser at 980-nm band

摘要

The Er~(3+)-Yb~(3+)-doped fiber has a broadened absorption spectrum, which means the pumping sources can work efficiently from 810 to 1 l00nm. Among them 980 nm is the maximum absorption (l0dB/km) wavelength. By energy transferring and multiphoton process, the visible and ultraviolet radiation occurs when the Er~(3+)-Yb~(3+)-doped fiber is pumped by the laser at 980-nm band. Further researches on the mechanism of the fluorescence of Er~(3+)-Yb~(3+)-doped silica fiber pumped by Ti: A1_2O_3 tunable laser at 980-nm band are helpful to the design of fiber up-conversion elements, such as fiber lasers and fiber amplifiers. The experimental results of the serial step-excited 'state absorption of Er~(3+)-doped fiber pumped by LD at 1 480 nm have been reported. In this note, some experimental results are reported for the first time to our knowledge: the up-conversion fluorescence spectrum of Er~(3+)-Yb~(3+) highly doped silica fiber pumped by Ti:Al_2O_3 laser at 970 nm, the 554-nm green fluorescence intensity versus pump power and wavelength of pumping source and the gain of 21-cm long Er~(3+)-Yb~(3+)-doped fiber amplifiers versus signal power when it is pumped by Ti: A1_2O_3 laser at 979 nm.