Four-wave mixing in two-layer microstructure fibres

The dispersion and waveguide characteristics of two-layer microstructure fibres with different layer filling factors are studied theoretically and experimentally. It is shown that by changing the filling factor of the second layer, it is possible to achieve lower effective cross sections for a mode and to control dispersion characteristics in a broader range. Frequency conversion during four-wave mixing with a frequency shift of 5460 cm^-1 (1098–687 nm) and efficiency of 0.1% at 200 mW of cw pump power was obtained for the first time in two-layer fibres fabricated for experiments.