Topology optimal design for optical waveguides using time domain beam propagation method

New topology optimal design approach for optical waveguide devices using a time domain beam propagation method (TD-BPM) is presented. A sensitivity analysis method for topology optimization using TD-BPM is formulated based on an adjoint variable method (AVM). A density method is used as a way to represent refractive index distribution. As design examples, a loss-reduced bending waveguide and a reflector are designed. It is confirmed that our design approach can surely enhance the performance of optical waveguide devices.