Enhancement of third-harmonic blue-violet light at 440 nm by erbium ions in Er^3+–GeO_2-doped silica monomode optical fibers pumped at 1319 μm

Abstract

The efficient generation of third-harmonic blue-violet light at 440 nm in short lengths of Er3+-doped germanosilicate single-mode optical fibers pumped at 1.319 μm is reported. Measurement indicates that the third-harmonic generation process that is due to a GeO2–SiO2 core is resonantly enhanced through the amplification of the signal light at 440 nm by population inversion of the erbium ions in the fiber core. An average signal power at 440 nm of ~5 μW was observed.