Structure-Adaptive Topology Optimization Framework for Photonic Band Gaps with TE-Polarized Sources

Abstract

Leveraging our structure-adaptive topology optimization framework based on the integration of the photonic density of states over a frequency window for the TM polarization of light [see A. Bahulikar et al., arXiv:2411.09165 (2025)], we show that the $\Gamma$-point and full Brillouin zone integration schemes can also recover two-dimensional photonic crystals for TE polarization. For the $\Gamma$-point formalism, we employ the scalar magnetic field formulation of the electromagnetic wave equation with independent sources polarized in the x and y directions. For the full Brillouin zone formalism, we employ the vector electric field formulation of the electromagnetic wave equation, again with independent sources polarized in the x and y directions. This work can simultaneously treat frequency-dependent optical response, allow for targeted optimization for a given frequency and reciprocal lattice vector pair, and inherently encourage binarized designs.