Slow light and voltage control of group velocity in resonantly coupled quantum wells

Pavel Ginzburg,Meir Orenstein

doi:10.1364/oe.14.012467

Abstract

We analyze slow light propagation in a coupled semiconductor quantum wells system exhibiting tunneling induced transparency. A group index as high as 85, for simple applicable GaAs/AlGaAs quantum wells structures, is predicted. Using DC voltage, the resonant tunneling rate can be altered and the related group index can be controlled over a broad range.

Highlights

In recent years intense research effort was exerted towards the realization of controllable slow light propagation [1]
Variety of implementations were proposed – both theoretically and experimentally including quantum interference phenomena – the most prominent is the Electromagnetically Induced Transparency (EIT) [2], nonlinear phenomena in optical fibers [3], nonlinear phenomena in semiconductors[4], linear dispersive waveguides, microcavities[5] and photonic crystals [6] exploiting near band edge dispersion
In order to realize an autonomous system that reduces the group velocity of a primary light field without a pump one, we employ here an alternative coupling mechanism to replace the pump light field. This scheme, namely tunneling induced transparency was previously proposed by Imamoglu group in relations to implementation of inversionless lasers and Fano interference [11]. It is based on two resonant quantum wells exhibiting a periodic Rabi oscillation of the electron due to the resonant tunneling effect – can serve as the 'second' arm in the V or Λ configurations of the EIT scheme

Summary

Introduction

In recent years intense research effort was exerted towards the realization of controllable slow light propagation [1]. In order to realize an autonomous system that reduces the group velocity of a primary light field without a pump one, we employ here an alternative coupling mechanism to replace the pump light field This scheme, namely tunneling induced transparency was previously proposed by Imamoglu group in relations to implementation of inversionless lasers and Fano interference [11]. It is based on two resonant quantum wells exhibiting a periodic Rabi oscillation of the electron due to the resonant tunneling effect – can serve as the 'second' arm in the V or Λ configurations of the EIT scheme. We propose and analyze the exploitation of the tunneling configuration for slow light generation and the application of a DC voltage to control the group velocity magnitude - a scheme that is favorable for implementation in semiconductor materials. Reports on slow light in solid state media (by coherent population trapping or by unique nonlinearities [13]) all required a second electromagnetic field and are substantially different from our proposed scheme

Anomalous dispersion of double quantum well configuration

Electrostatically controllable slowing down factor

Conclusion