Emission engineering in microdisk lasers via direct integration of meta-micromirrors.

Despite their excellent performance and versatility, the efficient integration of small lasers with other optical devices has long been hindered by their broad emission divergence. In this study, we introduce a novel approach for emission engineering in microdisk lasers, significantly enhancing their vertical emission output by directly integrating specially designed reflective metalenses, referred to as "meta-micromirrors". A 5 μm-diameter microdisk laser is precisely positioned at an 8 μm focal distance on a 30 × 30 μm meta-micromirror featuring a numerical aperture (NA) of 0.95, accomplished through micro-transfer printing techniques. Our experiments demonstrated a notable increase in the emission efficiency within an NA of 0.65. Specifically, we observed a 2.68-fold increase in the average emission from ten microdisk lasers. This integration not only enhances the emission efficiency of small lasers but also holds considerable implications for micro- and nano-photonic integrations. The results of this integration open up new possibilities in various fields, including photonic integrated circuits, bio-sensing technologies, and the development of quantum light sources.