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 (CCl4) 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 -9.376ps.nm(-1).km(-1 )at the pump wavelength of 0.98 mu m, generating broadband of 768nm and flat-top with only 0.3nJ of input energy and time duration of 90fs. In the meantime the dispersion property of the second fiber is anomalous, which equals 1.105ps.nm(-1).km(-1) at 1.3 mu m pump wavelength. The second fiber generates a SC spectrum of 1,751.1nm with input energy and time duration of 0.55nJ and 55fs, respectively. Proposed fibers are suitable for all-fiber SC sources which could lead to new low-cost all-fiber optical systems.