Experimental investigation of nonlinear frequency conversion in pure SiO/sub 2/-core monomode optical fibers pumped at 1.319 /spl mu/m: single pass and oscillators

Generation of intense visible picosecond pulses in the spectral region of 580-610 nm through efficient nonlinear frequency conversion of 1.319 /spl mu/m Nd:YAG Q-switched and mode-locked laser pulses in pure SiO/sub 2/-core single mode optical fibers was experimentally investigated. Peak powers of ten's of watts in single-pass arrangement and over 100 W in synchronously pumped amplifier/oscillators were obtained. The LP/sub 02/ mode signal light generated exhibits threshold power, critical fiber length, and an asymmetrical spectrum of a few nanometers. A phase-matched four-wave mixing process involving two photons around 800 nm and one photon around 1.4 /spl mu/m was responsible for the visible light generation. Varying the test fiber minimum dispersion wavelength, the four-wave mixing signal wavelength is shifted within the region of 580-610 nm.<
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