Modeling the Compression of Modulated Electromagnetic Pulses in a Straight Waveguiding Defect of Two-Dimensional Photonic Crystal

Abstract

The paper presents the results of numerical modeling of the compression of a frequency-modulated electromagnetic pulse in a straight waveguiding defect of a finite two-dimensional photonic crystal. For the first time, the time reversal method was used to accurately compute the temporal profile of a current pulse that excites an electromagnetic wave that is being compressed in such a structure, given that its temporal profile (electric field intensity) has a specified shape at a given point in space. The photonic crystal consists of an array of sapphire bars with a square cross-section of 1 mm × 1 mm, arranged in free space at a distance of 1 mm from each other. In this model, the boundaries of the frequency range containing the crystal’s band gap (from 35.6 to 46.5 GHz), the optimal width of the waveguiding defect (4 mm), and the shape of the excitation current pulse for the waveguiding defect with a length of 0.5 m were found. The obtained pulsed power amplification coefficient is approximately 7.48. A photonic-crystal analog of an H-plane horn antenna was used to radiate the compressed pulse into free space.