UC Berkeley

With the advent of the information era, the ever-growing need for bandwidth and computing power is calling for the development of highly integrated and compact photonic circuits where controlling light at the nano-scale becomes the most critical aspect of information processing and transfer. However, the inherent cross-talk in densely packed waveguides is a major roadblock toward ultra-high density photonic integrated circuits. As a result, the diffraction limit is often considered as the lower bound for ultra-dense integrated photonics circuits. In recent years, analogies between light propagation in waveguides and atomic physics dynamics were explored leading to non-intuitive light propagation patterns in waveguides.

In this dissertation we discuss the application of the Adiabatic Elimination concept from atomic physics into integrated photonics. We experimentally demonstrate that this scheme allows the control via a dark mode of the coupling between two outer waveguides in a three-waveguide configuration. In particular, we show that at the nano-scale, where higher order couplings occur, a zero coupling between all the waveguides can be achieved, thus allowing perfect shielding in very dense waveguides configuration. We also show the applicability of the Adiabatic Elimination in larger arrays of waveguides.

We conclude by showing how dark mode interaction applied to a plasmonic system leads to a significant linewidth narrowing of the plasmonic resonance thus reducing the losses typically associated to these systems.