Supercontinuum generation in photonic crystal fibres with core filled with toluene

A photonic crystal fibre with hollow core filled with toluene is considered as a new system for coherent supercontinuum generation. The dispersion characteristics are studied for various geometrical parameters of photonic crystal fibres. Two structures with lattice constant 2 μm, filling factors d/Λ 0.3 and 0.35 and toluene core of diameters of 3.34 and 3.23 μm have flat dispersion in the near infrared range. The structure with d/Λ = 0.3 has all-normal dispersion characteristics in whole near-infrared wavelength range, while the second structure (d/Λ = 0.35) has anomalous dispersion for wavelengths longer than 1.5 μm. Although confinement losses in the considered structures are as high as 0.4 dB cm−1, we show that the generation of coherent supercontinuum in the range 1.0–1.7 μm with the pulse energy conversion of 16% is feasible in 4 cm long fibre samples with standard fibre femtosecond lasers.