Linear and nonlinear optical spectroscopy of a strongly-coupled microdisk-quantum dot system

TL;DR

This paper demonstrates strong coupling and nonlinear optical effects in a microdisk-quantum dot system using fiber taper waveguides, revealing vacuum Rabi splitting and low-photon saturation.

Contribution

It introduces a fiber taper waveguide technique for direct optical spectroscopy of microdisk-quantum dot systems, enabling observation of strong coupling and nonlinear saturation effects.

Findings

Observation of vacuum Rabi splitting in transmitted and reflected signals

Demonstration of cavity-QD response saturation at less than one intracavity photon

Use of fiber coupling to probe steady-state nonlinear properties

Abstract

A fiber taper waveguide is used to perform direct optical spectroscopy of a microdisk-quantum-dot system, exciting the system through the photonic (light) channel rather than the excitonic (matter) channel. Strong coupling, the regime of coherent quantum interactions, is demonstrated through observation of vacuum Rabi splitting in the transmitted and reflected signals from the cavity. The fiber coupling method also allows the examination of the system's steady-state nonlinear properties, where saturation of the cavity-QD response is observed for less than one intracavity photon.