Discrete photonics: Shaping inhomogeneous waveguide arrays to control guided light on chip - “guidonics”

We show that elegant and inspiring photonics can be achieved in inhomogeneous waveguide arrays. We engineer light flow in waveguide arrays via patterning the coupling strength between waveguides which is key for light distribution within the discrete metamaterial. Applications range from multiport beam-steering discrete analogues of reflection and refraction for Bloch waves to a threshold-less all-optical transistor. We demonstrate an extensive theoretical toolbox for the design of functionalized inhomogeneous waveguide arrays and exemplify the expected effects on InP semiconductor based structures.