Tuning the mode-splitting of a semiconductor microcavity with uniaxial stress

TL;DR

This paper presents a reversible, in-situ method to tune mode-splitting in semiconductor microcavities using uniaxial stress, exploiting the photoelastic effect to achieve up to 11 GHz adjustment, enhancing control for quantum technologies.

Contribution

The work introduces a novel, reversible technique to control mode-splitting in microcavities via uniaxial stress, with quantitative analysis of the tuning mechanism.

Findings

Maximum tuning of ~11 GHz achieved.

Mode-splitting can be controlled across the stopband.

Stress is quantified through quantum dot photoluminescence shifts.

Abstract

A splitting of the fundamental optical modes in micro/nano-cavities comprising semiconductor heterostructures is commonly observed. Given that this splitting plays an important role for the light-matter interaction and hence quantum technology applications, a method for controlling the mode-splitting is important. In this work we use an open microcavity composed of a "bottom" semiconductor distributed Bragg reflector (DBR) incorporating an n-i-p heterostructure, paired with a "top" curved dielectric DBR. We measure the mode-splitting as a function of wavelength across the stopband. We demonstrate a reversible in-situ technique to tune the mode-splitting by applying uniaxial stress to the semiconductor DBR. The method exploits the photoelastic effect of the semiconductor materials. We achieve a maximum tuning of $\sim$11 GHz. The stress applied to the heterostructure is determined by observing the photoluminescence of quantum dots embedded in the sample, converting a spectral shift to a stress via deformation potentials. A thorough study of the mode-splitting and its tuning across the stop-band leads to a quantitative understanding of the mechanism behind the results.