Optimal Design of Photonic Devices Using Time-Domain Beam Propagation Method

In this paper, we introduce shape and topology optimal design approach making use of a time-domain beam propagation method (TD-BPM) for optical waveguide devices. The design approach is based on sensitivity analysis to density parameters, and the sensitivity is computed by an adjoint variable method (AVM). We describe how to compute the sensitivity in the case of using the standard BPM which is a frequency domain method, then adapt it to the case of using the TD-BPM. As a numerical design example, a reflector is optimized using our design approach with the TD-BPM, and we study on its advantage over the case of using frequency domain techniques.