Photonic integrated circuits are the devices in which multiple devices are integrated in a single substrate to obtain the functionality of entire components as a single chip. In this paper, the photonic crystal based optical 4 x 4 routers for photonic integrated on chip networks is designed and the characteristics of the same are reported. The investigation of the router is extended by varying the crystal radius and materials. The materials such as germanium (Ge) of RI 4.0029, gallium arsenide of RI 3.3219 and indium phosphate (InP) of RI 3.457 are used for the router formation. Performance of the router is examined for the wavelength gamut of 1500-1600 nm and the routed wavelengths are tabulated. Crosstalk (CT) and insertion loss (IL) are the crucial determinants of the router and compared to all the router configurations Ge pillared router has minimum CT and InP pillared router has minimum IL. The diminutive structured router in the size of 33 mu m x 36 mu m has been depicted to place the footprints on the integrated photonics of ultra- compact device employment.