Ultrafast Simulation and Optimization of Nanophotonic Devices with Integral Equation Methods

• Published in: ACS photonics 2019-12, Vol.6 (12), p.3233-3240
• Main Authors: Sideris, Constantine, Garza, Emmanuel, Bruno, Oscar P
• Format: Article
• Language: English
• ISSN: 2330-4022; 2330-4022
• DOI: 10.1021/acsphotonics.9b01137

Integrated photonics is poised to become a billion-dollar industry due to its vast array of applications. However, designing and modeling photonic devices remains challenging due to the lack of analytical solutions and difficulties with numerical simulation. Recently, inverse design has emerged as a promising approach for designing photonic devices; however, the current implementations require major computational effort due to their use of inefficient electromagnetic solvers based on finite-difference methods. Here we report a new, highly efficient method for simulating devices based on boundary integral equations that is orders of magnitude faster and more accurate than existing solvers, almost achieves spectral convergence, and is free from numerical dispersion. We develop an optimization framework using our solver based on the adjoint method to design new, ready-to-fabricate devices in just minutes on a single-core laptop. As a demonstration, we optimize three different devices: a nonadiabatic waveguide taper, a 1:2 1550 nm power splitter, and a vertical-incidence grating coupler.