Supercontinuum generation in C₆H₅NO₂-core photonic crystal fibers with various air-hole size

In this paper, we demonstrated the ability of a hexagonal photonic crystal fiber (PCF) with a hollow core infiltrated with nitrobenzene (C6H5NO2) to generate a broad SC spectrum at low peak powers. Due to the non-uniformity of the air hole diameters, our new design allows for simultaneous optimization of features, resulting in near-flat, near-zero dispersion, a small effective mode area, and low attenuation for efficient spectral broadening. We selected two optimal structures from the simulation results to analyze the nonlinear properties and super-continuum generation. The first fiber, #HF1, with a lattice constant of 1.0 mu m and a filling factor of 0.45, operates in all-normal dispersion and produces spectral SC ranging from 0.81 mu m to 1.919 mu m with a pump wavelength of 1.56 mu m, a pulse duration of 90 fs, and peak power of 0.133 kW propagated in a 1 cm fiber length. The #HF2 fiber (lattice constant of 2.0 mu m, filling factor of 0.3) has an extended SC spectrum from 0.792 mu m to 3.994 mu m, a pump wavelength of 1.55 mu m, a pulse width of 110 fs, a peak power of 0.273 kW propagated in a 15 cm fiber length. The proposed fiber may be a new-generation optical fiber suitable for low-peak power all-fiber optical systems to replace glass-core glass fiber.