EXPERIMENTAL INVESTIGATION OF NONLINEAR FREQUENCY-CONVERSION IN PURE SIO2-CORE MONOMODE OPTICAL FIBERS PUMPED AT 1.319 MU-M - SINGLE-PASS AND OSCILLATORS

Generation of intense visible picosecond pulses in the spectral region of 580-610 mn through efficient nonlinear frequency conversion of 1.3 19 mu m Nd:YAG Q-switched and mode-locked laser pulses in pure SiO2-co re single mode optical fibers was experimentally investigated, Peak po wers of ten's of Watts in single-pass arrangement and over 100 W in sy nchronously pumped amplifier/oscillator were obtained, The LP(02) mode signal light generated exhibits threshold power, critical fiber lengt h, and an asymmetrical spectrum of a few nanometers. A phase-matched f our-wave mixing process involving two photons around 800 nm and one ph oton around 1.4 mu m was responsible for the visible light generation. Varying the test fiber minimum dispersion wavelength, the four-wave m ixing signal wavelength is shifted within the region of 580-610 nm.