Spontaneous emission inhibition of telecom-band quantum disks inside single nanowire on different substrates

TL;DR

This study examines how the spontaneous emission of telecom-band quantum disks in nanowires is inhibited differently depending on substrate material, disk dimensions, and nanowire orientation, with implications for photonic device integration.

Contribution

It provides experimental and theoretical analysis of emission inhibition in quantum disks within nanowires on various substrates, highlighting substrate effects on emission suppression.

Findings

Inhibition factor decreases from 4.6 to 2.5 when changing substrate from SiO2 to Si.

Inhibition is significantly reduced in NWs on high-refractive index substrates.

Experimental results agree with mode coupling calculations.

Abstract

We investigate the inhibited spontaneous emission of telecom-band InAs quantum disks (Qdisks) in InP nanowires (NWs). We have evaluated how the inhibition is affected by different disk diameter and thickness. We also compared the inhibition in standing InP NWs and those NWs laying on silica (SiO2), and silicon (Si) substrates. We found that the inhibition is altered when we put the NW on the high-refractive index materials of Si. Experimentally, the inhibition factor $\zeta$ of the Qdisk emission at 1,500 nm decreases from 4.6 to 2.5 for NW on SiO2 and Si substrates, respectively. Those inhibitions are even much smaller than that of 6.4 of the standing NW. The inhibition factors well agree with those calculated from the coupling of the Qdisk to the fundamental guided mode and the continuum of radiative modes. Our observation can be useful for the integration of the NW as light sources in the photonic nanodevices.