A review on the techniques for building all-optical photonic crystal logic gates

Recently, photonic crystals have emerged to contribute in building all-optical computers and optical communication systems. This is due to the urgent need for faster computers and mobiles with high speed processing of data and with higher data transmission rates. In this paper we review the operation of photonic crystal logic gates and depict the different design techniques that produce a wide range of structures realizing the logic functions. We investigate several techniques such as self-collimated beam, multi-mode interference, interference based defect method and nonlinear Kerr materials based gates. As a summary, we compare the various key features of each design and illustrate the advantages and disadvantages of each design technique.