Systematic and robust design of photonic crystal waveguides by topology optimization

Abstract

A robust topology optimization method is presented to consider manufacturing uncertainties in tailoring dispersion properties of photonic crystal waveguides. The under, normal and over‐etching scenarios in manufacturing process are represented by dilated, intermediate and eroded designs based on a threshold projection. The objective is formulated to minimize the maximum error between actual group indices and a prescribed group index among these three designs. Novel photonic crystal waveguide facilitating slow light with a group index of ng = 40 is achieved by the robust optimization approach. The numerical result illustrates that the robust topology optimization provides a systematic and robust design methodology for photonic crystal waveguide design.