Impact of Non-linear Spectral Processes on NIR and Visible Emission Characteristics in Bismuth Doped Silicate Fibres

Abstract

Bismuth doped fibres (BDFs) emit in the NIR and visible wavelength range. For instance, BDFs produce emissions, mainly at 1420 nm and 420 nm under 830 nm pump. These emissions are closely related to non-linear spectral processes like excited state absorption (ESA), upconversion (UC), non-radiative decay mechanism, etc. Emission produced in BDFs at 1420 nm is promising for the development of BDF laser and amplifier; emission observed at 420 nm can be useful for medical applications. Characteristics of Bi associated emissions at 1420 nm and 420 nm and impact of ESA, UC and non-radiative emission processes on these emissions are investigated in this work when BDF is pumped under 830 nm. In addition, the effect of Bi concentration on the intensities of Bi emissions at 1420 nm and 420 nm is evaluated in an analytical approach.