Wideband near-i.r. continuum (0.7¿2.1 ¿m) generated in low-loss optical fibres

A wideband near-infrared continuum is obtained by nonlinear optical interactions in low-loss single-mode and multimode silica fibres pumped by pulses from a Q-switched Nd:y.a.g. laser. With 50 kW pump power coupled into a 315 m long 33 ¿m core-diameter low-loss multimode fibre, a continuum spanning the spectral range 0.7¿2.1 ¿m with a total power of 12 kW is generated. In single-mode and low-mode-number fibres a similar continuum of lower power has been obtained. Such continuum sources are useful for measurement of fibre properties as well as for spectroscopic study of other optical materials.