Ultra-Broadband Beam Splitting in Three-Waveguide System with Dissipation

While integrated optical devices must be often designed to operate at a specific light wavelength, disposing of achromatic structures with a wide spectral response is generally of strong interest. In this context, approaches based on spatially and adiabatically evolving configurations have recently been proposed as robust solutions for various waveguide-based broadband and design-tolerant functionalities [1] - [4] . Here we propose a novel approach for robust ultra-broadband beam splitting that does not need any adiabatic evolution of the waveguide’s parameters. Our scheme turns dissipation in one of three waveguides (WGs) into an advantage and may be directly associated to quantum population transfer through a decaying intermediate state [5] .