Near-infrared nano-spectroscopy of semiconductor quantum dots using a phase-change mask layer

Abstract

We propose a technique that uses an optical mask layer of a phase-change material (PCM), which is used for rewritable optical recording media, to achieve highly sensitive near-field imaging spectroscopy of single semiconductor quantum constituents at optical telecommunication wavelengths. An amorphous nanoaperture allows imaging spectroscopy with a high spatial resolution and high collection efficiency. This is due to the large optical contrast between the crystalline and amorphous phases of the phase-change material at visible wavelengths and its high transparency at near-infrared wavelengths. We demonstrate the effectiveness of the method by numerical simulations and photoluminescence measurements of InAs/InP quantum dots.