Efficient shortcut techniques in evanescently coupled waveguides

TL;DR

This paper adapts Shortcut to Adiabatic Passage techniques, originally from atomic physics, to photonic waveguide couplers, enabling faster, efficient power switching with reduced device length through engineered coupling parameters.

Contribution

It demonstrates the application of SHAPE methods to waveguide couplers, achieving rapid, complete power switching and significant length reduction.

Findings

Efficient and complete power switching achieved.

Coupler length can be significantly reduced.

Engineered coupling coefficients enhance performance.

Abstract

Shortcut to Adiabatic Passage (SHAPE) technique, in the context of coherent control of atomic systems has gained considerable attention in last few years. It is primarily because of its ability to manipulate population among the quantum states infinitely fast compared to the adiabatic processes. Two methods in this regard have been explored rigorously, namely the transitionless quantum driving and the Lewis-Reisenfeld invariant approach. We have applied these two methods to realize SHAPE in adiabatic waveguide coupler. Waveguide couplers are integral components of photonic circuits, primarily used as switching devices. Our study shows that with appropriate engineering of the coupling coefficient and propagation constants of the coupler it is possible to achieve efficient and complete power switching. We also observed that the coupler length could be reduced significantly without affecting the coupling efficiency of the system.