Vol. 37, Issue 1-2, pp. 101-106 (2007)

Abstract

Careful, intensity and spectral examinations of fluorescence in the process of infrared-to-visible upconversion, observed perpendicularly to the excited ZBLAN:Er³⁺ optical fiber (side fluorescence), and at the fiber end, point to the existence of amplified spontaneous emission (ASE), when the fiber is long enough. We have observed the narrowing of the fluorescence band centered at 544 nm (⁴S_3/2 -> ⁴I_15/2 transition) and an increase in the ASE intensity, when the fiber is pumped at 809 nm with a laser diode.