Four photonic crystal fiber (PCF) structures have been investigated using Finite Difference Time Domain (FDTD) method. These structures vary in structure and material filled in holes of cladding region. Elliptical holes equal to four times the area of circular holes have been introduced to report high birefringence. Moreover, air filled and ethanol filled holes are introduced to provide a comparison of propagation characteristics. Structure D, with lead silicate as background material and ethanol filled holes provides much better results than all other PCFs structures studied in this paper. However, other structures studied in this paper are also found to be eligible for wide application in optical communication system, optical coupler and for sensing applications.