Photonic crystal fibres infiltrated with nitrobenzene for low peak power supercontinuum generation in NIR to MIR region

We present a comparative study of silica-based Photonic Crystal Fibres infiltrated with nitrobenzene to generate supercontinuum light with low peak power in the near-infrared to mid-infrared ranges. Using a full vectorial finite element method, we analyzed three designs: symmetrical circular (#C) and asymmetrical elliptical X-polarised (#EX) and Y-polarised (#EY). The circular design showed a dispersion of + 30.211 ps/nm/km, effective mode area of 4.13 mu m2, and nonlinear coefficient of 1962.0 W-1 km-1 at 1.55 mu m. The elliptical designs had dispersions of -10.852 ps/nm/km (#EX) and -8.356 ps/nm/km (#EY), with effective mode areas of 4.55 and 4.60 mu m2, and nonlinear coefficients of 1780.9 and 1761.5 W-1 km-1. Using a 10 mm fiber, 50 fs laser pulse, and 650 W pump power, we achieved supercontinuum spectra ranging from 1.3-2.0 mu m (#C), 0.9-2.3 mu m (#EX), and 1.0-2.4 mu m (#EY). These designs are promising for biomedical and sensing applications.