Slow and Stopped Light in Dynamic Moir\'e Gratings

TL;DR

This paper presents a theoretical model for dynamic Moiré gratings that can significantly slow or stop light, outperforming static gratings by dynamically tuning coupling strength to enhance group velocity reduction and bandwidth control.

Contribution

It introduces a dynamic Moiré grating model capable of tunable slow and stopped light with improved performance over static gratings, including a proposed electro-optic implementation.

Findings

Dynamic modulation enhances slow light performance.

Bandwidth modulation is achievable via spectrum alteration.

Proposed electro-optic realization using nonlinear media.

Abstract

We investigate a theoretical model for a dynamic Moir\'e grating which is capable of producing slow and stopped light with improved performance when compared with a static Moir\'e grating. A Moir\'e grating superimposes two grating periods which creates a narrow slow light resonance between two band gaps. A Moir\'e grating can be made dynamic by varying its coupling strength in time. By increasing the coupling strength the reduction in group velocity in the slow light resonance can be improved by many orders of magnitude while still maintaining the wide bandwidth of the initial, weak grating. We show that for a pulse propagating through the grating this is a consequence of altering the pulse spectrum and therefore the grating can also perform bandwidth modulation. Finally we present a possible realization of the system via an electro-optic grating by applying a quasi-static electric field to a poled $\chi^{(2)}$ nonlinear medium.