Abstract: We have performed a numerical analysis of the structural dependence of the PCF parameters towards ultra-flat dispersion in the C-band of communication wavelength. The technique is based on regular square-lattice PCF with all the air-hole of same uniform diameter and the effective size of the air-holes are modified with a selective infiltration of the air-holes with liquids. The dependence of the PCF structural parameters namely air-hole diameter and hole-to-hole distance along with the infiltrating liquid has been investigated in details. It is shown that the infiltrating liquid has critical influence on both the slope and value of dispersion, while pitch only changes the dispersion value whereas air-hole diameter modifies the slope of the dispersion. Our numerical investigation establishes dispersion values as small as 0±0.58ps/(nm-km) over a bandwidth of 622nm in the communication wavelength band (C-band). The proposed design study will be very helpful in high power applications like broadband smooth supercontinuum generation, ASE suppressed amplification etc.Abstract: We have performed a numerical analysis of the structural dependence of the PCF parameters towards ultra-flat dispersion in the C-band of communication wavelength. The technique is based on regular square-lattice PCF with all the air-hole of same uniform diameter and the effective size of the air-holes are modified with a selective infiltration of t...Show More