Applications of Self-Collimated Properties of Photonic Crystal in 3D Imaging Lidar System

Photonic crystals (PCs) are increasingly attracting attention due to their ability to control light propagation.In this paper,the dispersion properties of a two-dimensional (2D) square lattice PCs with plane- wave expansion (PWE) method are presented,the equi-frequency contours and the band structure are analyzed,and the alignment transmission characteristics are simulated by using the finite difference time domain (FDTD) method.In addition,for the wavelength of 1.55 m,a kind of application structure with the lattice constant a=405 nm and the radius of air holes R=135 nm which can restrict the transmission of beams in photonic crystal without defect is proposed and simulated.The structure which can collimate the output beam and compress its divergence angle is easy to design.It has wide application prospects in optical communication and three-dimensional (3D) imaging lidar systems.