A 60° photonic crystal waveguide bend with improved transmission characteristics

Abstract

Corresponding author: ma_kh303-mail@stu.um.ac.irIn this paper, a 60° waveguide bend is designed in a two-dimensional (2D) photonic crystal (PC)slab to provide high transmission over a large bandwidth. We apply geometrical modification inthe bend region to improve the transmission characteristics. This modification results in increasingthe relative bandwidth from 6.5% to 25.7% of photonic band gap width. Using the effectiverefractive index, the structures designed are simulated by the 2D finite-difference time-domain(FDTD) method. As a specific application, we us e the improved bend structure in a PC waveguidedirectional coupler and show that the drop output increases significantly.Keywords: photonic crystal, waveguide, bend, bandwidth, slab structures.