On-chip optical true time delay lines featuring one-dimensional fishbone photonic crystal waveguide

Abstract

In this paper, we present on-chip optical true time delay lines based on slow light one-dimensional (1D) fishbone photonic crystal waveguides (FPCWs). The structural slow light is generated by modulating the index guided optical mode with periodically arranged sidewalls along the propagation direction. Due to the reduced mode overlap with the rough etched surface, the propagation loss of the 1D FPCW is significantly reduced compared to the two-dimensional photonic crystal waveguide. A delay time of 65 ps/mm is observed experimentally.