Threshold with Photon Recycling in Nanolasers with Extreme Dielectric Confinement

On-chip optical interconnects [1] would enable denser integration of electronics and photonics, paving the way to information and communication technologies with higher energy efficiency and more complex functionalities. This revolution requires a new generation of semiconductor lasers, with ultra-small footprint, low noise and reduced energy consumption. Emerging dielectric cavities comprising a bowtie geometry [2] localize photons to an effective mode volume far below the so-called diffraction limit, while maintaining a high quality factor. These cavities with extreme dielectric confinement (EDC) may lead to nanolasers with unprecedented lightmatter coupling rate and near-unity spontaneous emission factor. Besides promising ultralow threshold current and high modulation speed, EDC lasers fundamentally call for reconsidering the standard approach [3] to computing the lasing threshold.