Abstract

Among many nonlinear effects in optical fibers, frequency up-conversion has been much exploited recently. In the process an optical fiber efficiently nonlinearly converts infrared (IR) radiation into visible light, as reported for polarization preserving fibers¹ and rare-earth doped silica fibers² in singlepass arrangements, and also for fiber lasers.³ In this work we report on the efficient frequency up-conversion of 1.319 μm radiation into 580-nm light with peak powers as high as 20 W, in a single-span of single-mode pure SiO₂-core optical fiber. The yellow laser beam-like signal generated propagates in the LP₀₂ mode and exhibits an asymmetrical broadband spectrum (~3.5 nm) with long tail toward high frequencies. The frequency up- conversion process presents a threshold power that depends upon the fiber length and also, for a fixed power, a critical fiber length at which the process starts to build up.

© 1993 Optical Society of America