Enhanced Quantum Dot Light Emission at Telecom Wavelengths on Metallic Mirrors

We demonstrate the integration of molecular beam epitaxy (MBE)-grown InAs/InP quantum dots (QDs) on gold thin films, achieving a fivefold enhancement of telecom-wavelength emission compared with QDs grown on distributed Bragg reflectors (DBRs). Micro-photoluminescence (µ-PL) spectroscopy reveals a pronounced increase in PL intensity from the Au-integrated structures, highlighting the enhanced optical response enabled by the metallic mirror effect. Reflectivity measurements exhibit a characteristic dip near the QD emission wavelength, indicating increased optical absorption and reduced reflectance, consistent with improved coupling of incident light into the fabricated structure. Power-dependent measurements demonstrate background-free exciton and biexciton emission from single QDs with resolution-limited linewidths. Polarization-dependent measurements further reveal an ultra-small excitonic fine-structure splitting, reaching values as low as ~2 μeV. Finally, statistical analysis of multiple QDs confirms the reproducibility and robustness of the observed optical properties.