Photonic-crystal ultrashort bends with improved transmission and low reflection at 1.55 μm

Abstract

We propose and demonstrate improved designs in order to increase the transmission level through double 60°-bend photonic-crystal-based waveguides. These bends are defined in a two-dimensional photonic crystal (PC) patterned into a GaInAsP slab on InP substrate. Transmission spectra calculated using a two-dimensional finite difference time domain method that accounts for radiation losses, as well as measurements, demonstrate enhancement of the transmission when moving holes in the corner. As expected a drop in reflection is obtained. The sensitivity to the PC guide width is also evidenced.