Complete and robust light transfer in three-waveguide coupler by shortcut to adiabaticity

A novel design for complete transfer and robust three-waveguide coupler is presented in this paper, which employs shortcut to adiabaticity (STA) based on stimulated Raman adiabatic passage (STIRAP). Most recently, some remarkable papers on STA of STIRAP [Phys. Rev. A 94(6), 063411 (2016) and Nat. Comm. 7, 12479 (2016)] have been proposed in both theoretical and experimental configurations. In this paper, we propose to design a novel three-waveguide coupler by employing STA based on STIRAP, which can achieve much shorter device length and also maintain the robust performance against perturbations on device geometry parameters compared to previous devices. This finding significantly improves the performance and fabrication of integrated optical devices to build up more compactable devices.