The paper report new results of chromatic dispersion in Photonic Crystal
Fibers (PCFs) through appropriate designing of index-guiding triangular-lattice
structure devised, with a selective infiltration of only the first air-hole
ring with index-matching liquid. Our proposed structure can be implemented for
both ultra-low and ultra-flattened dispersion over a wide wavelength range. The
dependence of dispersion parameter of the PCF on infiltrating liquid indices,
hole-to-hole distance and air-hole diameter are investigated in details. The
result establishes the design to yield a dispersion of 0+-0.15ps/ (nm.km) in
the communication wavelength band. We propose designs pertaining to
infiltrating practical liquid for near-zero ultra-flat dispersion of
D=0+-0.48ps/ (nm.km) achievable over a bandwidth of 276-492nm in the wavelength
range of 1.26 {\mu}m to 1.80{\mu}m realization.Comment: 6 pages, 13 figures, 1 tabl