Differaction free light guiding in channel less 2D square array waveguides using self-collimation

In this paper we investigated one of the most recently introduced phenomena in Photonic Crystal structures, responsible for collimating and guiding light through the preferred direction without diffraction, to design self-collimation based waveguide. The advantage of using self-collimation property to design waveguides is discussed and the idea is compared with conventional band gap engineered waveguides made by defects. The square lattice waveguide presented in this article, guides the 1.55μm wavelength in a considerable propagation length of about 26μm and 30μm without diffraction and divergence for TE and TM polarizations, respectively. The simulations are done using the Plane Wave Expansion and Beam Propagation methods and the results confirm the value of using self-collimation in waveguide design.