Optical parametric amplification in the normal dispersion regime using a PCF

Photonic crystal fibres (PCFs) can now be constructed exhibiting a wide range of dispersion profiles and nonlinearities, which have enabled the demonstration of many nonlinear optical phenomena. In our experiments, we have used a range of fibres with varying zero group velocity dispersion (GVD) points around the visible red pump wavelength. Upshifted sidebands can be generated which span the entire visible range from the blue to the red, whilst the corresponding downshifted sidebands range from approximately 750 to 1000 nm. We have demonstrated that newly developed PCFs can be used as efficient parametric frequency generators, and, in principle, a PCF based fibre optic parametric oscillator could generate a tunable all solid state source spanning the entire visible spectrum. Such a source would, however, require the production of PCFs with very uniform fibre diameter and the development of higher power single transverse mode solid state lasers in the red.