We investigate the optical characteristic, transverse magnetic (TM) and transverse electric (TE) band of two-dimensional (2D) square lattice photonic crystal structure, which is composed of cylindrical air regions positioned at the coers of the square shaped dielectric rods. We obtain the wide photonic bandwidths between TM1–TM2 and TM3–TM4 bands. According to the results, we demonstrate the band gaps close to each other in the TM and TE frequencies for pro-posed structures. The resulting photonic gaps are formed to be about 8％at the higher frequencies of TE modes (TE4–TE5) and TM modes (TM7–TM8 and TM9–TM10). In addition, we examine isotropically generated structures for light guiding properties and observe that the light is directed in a particular route without using any defl ection. We also investigate the self-collimation effect with the designed structure. The obtained results reveal the infl uences of the radius of cylindrical air holes and the angle between these air holes on absolute and partial photonic band gaps. Moreover, we observe the TM and TE band gaps that overlap. It is thought that the obtained band overlap will provide an easy way to produce the photonic crystals in practical applications like photonic insensitive waveguide. It is also believed that these results can provide the photonic crystal structures to work as a beam defl ecting and beam router in integrated optical circuit applications.