Proposal for Supercontinuum Generation by Optofluidic Infiltrated Photonic Crystal Fibers

We propose a technique based on optofluidic infiltration to design a photonic crystal fiber (PCF) to control chromatic dispersion for supercontinuum generation. Selectively infiltrating the PCF air-holes with an optical fluid having an appropriate refractive index, we have achieved a PCF with low confinement loss and ultra-flattened near zero dispersion centered about λ_ZD ~ 1325 nm, without a need for nano-scale geometrical tuning. Numerical simulations show that femto-second pulses, with center wavelengths within the range of 1250 nm ≤ λ₀ ≤ 1625 nm, can generate relatively flat supercontinuum spectra as wide as 640 to 1180 nm, passing through a 250-mm long PCF whose dispersion profile is engineered via selective optofluidic infiltration. Simulations also show that optical fluid with refractive index of n_F = 1.32 for input signals having the aforementioned range of wavelengths result in the widest flat supercontinua. This is attributed to the smallest corresponding effective mode area as well as the smallest and flat corresponding dispersion both of which enhance the PCF nonlinearities.