Efficient frequency upconversion of 1319-μm radiation into intense yellow light at 580 nm in pure SiO_2-core monomode optical fiber

Abstract

Generation of intense visible light at 580 nm with peak powers as high as 20 W through efficient frequency upconversion of 1.319-μm Nd:YAG laser pulses in a single span of pure SiO2-core single-mode optical fiber is reported. The yellow-light signal generated at 580 nm propagates in the LP02 mode and exhibits an asymmetrical 3.5-nm bandwidth spectrum with a long tail toward high frequencies. The frequency upconversion process presents a threshold power, which depends on the fiber length, and a critical length of a few meters, at which the mechanism starts to build up. A conversion efficiency of fundamental radiation at 1.319 μm into visible light at 580 nm of approximately 0.5% in a 20-m length of pure silica-core fiber at 5.0-kW peak pump power was measured.