Flat-top and broadband supercontinuum generation in CCl4-filled circular photonic crystal fiber

In this work, a flat-top and broadband supercontinuum (SC) generation in photonic crystal fibers (PCFs) infiltrated with carbon tetrachloride ([Formula: see text] with different air hole diameters in the cladding has been introduced. The optical properties of the fundamental mode are analyzed by numerical simulation. Based on the obtained results, two optimized PCFs with small dispersion are proposed and verified against SC generation in detail. The first fiber has an all-normal dispersion of −9.376[Formula: see text]ps.nm[Formula: see text].km[Formula: see text] at the pump wavelength of 0.98[Formula: see text][Formula: see text]m, generating broadband of 768[Formula: see text]nm and flat-top with only 0.3[Formula: see text]nJ of input energy and time duration of 90[Formula: see text]fs. In the meantime the dispersion property of the second fiber is anomalous, which equals 1.105[Formula: see text]ps[Formula: see text]⋅[Formula: see text]nm[Formula: see text][Formula: see text]⋅[Formula: see text]km[Formula: see text] at 1.3[Formula: see text][Formula: see text]m pump wavelength. The second fiber generates a SC spectrum of 1,751.1[Formula: see text]nm with input energy and time duration of 0.55[Formula: see text]nJ and 55[Formula: see text]fs, respectively. Proposed fibers are suitable for all-fiber SC sources which could lead to new low-cost all-fiber optical systems.