Photonic band structure investigation of two-dimensional Bragg reflector mirrors for semiconductor laser mode control

Abstract

A theoretical study that follows the lines of previous photonic band structure investigations has been undertaken in search of a two-dimensional (2D) periodic dielectric structure that exhibits a certain type of photonic band structure for application as an external feedback mirror for laser diode arrays and broad-area devices. Instead of looking for an absolute band gap for a band of frequencies, we are particularly interested in structures that exhibit only stop bands, i.e., bands with a narrow extent in both frequency and angle. This type of reflecting structure, which can also be termed a 2D Bragg reflector, could provide improved mode control for both longitudinal and transverse characteristics of the modes for these devices. Our study, which employed photonic band structure calculational methods, showed that square lattice dielectric structures exhibit such stop bands for both TE and TM waves and could be used as photonic band structure mirrors to induce better mode control.