Abstract
A new PCF structure with variation in geometry of holes in the cladding region have been investigated using FDTD method. Holes of circular and elliptical geometry have been used for designing the proposed PCF. Elliptical holes have area four times greater than that of circular holes. Investigated structure has shown excellent results. Obtained birefringence is of the order 10-2. Relative sensitivity obtained is high. Also it reports ultra low confinement loss over wide range of optical wavelength. Besides these, endless single mode property has also been ensured in this paper.