No abstract

Function expansion based topology optimization method for optical waveguide devices has been proposed as an automatic design method which can produce an optimal device structure having an arbitrary topology. In this paper, we aim to extend the function expansion based topology optimization method to the design problems of three-dimensional photonic devices with structural variation in the depth direction. We confirm the effectiveness of our approach through the design example of the polarization splitter and rotator which utilizes structural asymmetry in the depth direction.