A novel design of a two-channel optical add–drop multiplexer based on a self-rolled-up microtube (SRM) is presented. This design consists of an SRM that has a parabolic lobe-like pattern along the tube’s axial direction, as well as straight silicon waveguides and a 180° waveguide bend. The vertical configuration of the SRM and waveguides is analyzed by the coupled mode theory for achieving the optimum gap. In the critical coupling regime, when the device serves as an optical demultiplexer, the m
