Monolithically integrated low-loss silicon photonic wires and three-dimensional tapered couplers fabricated by self-profile transformation

摘要

A subwavelength silicon photonic wire integrated with three-dimensional (3D) tapered couplers fabricated through self-profile transformation is presented. Unlike the conventional process of defining the silicon wire by etching, the profile transformation, which is induced by surface diffusion of silicon atoms during hydrogen annealing, is applied on as-etch silicon structures to make photonic wires. Additionally, this process is able to reduce sidewall roughness to be less than 1 nm, substantially meliorating the unwanted scattering loss. Exploiting this technology, the authors demonstrated that the photonic wire has low propagation loss of 1.26 dB/cm and the 3D tapered coupler has coupling efficiency of 54%.