In this paper photonic crystal fibers (PCFs) with different refractive index profiles have been investigated. A PCF structure with triangular refractive index profile of seven hexagonal rings show better performance compared to other simulated structures having same geometry but with different refractive index profiles. Dispersion characteristics of the triangular refractive index PCFs have nearly zero flattened dispersion with birefringence of the order of 2 10-2. Full vector finite difference time domain (FDTD) method has been applied for simulation using OptiFDTD software. These fibers may be used in optical communication system and optical sensors.