Photonic Crystal Ring Lasers Grown on SOI

This is the authors' abstract. We don't add key points for this paper.

Photonic crystal and whispering-gallery-mode resonators are the leading platforms for high-performance microcavity lasers. However, both face inherent trade-offs: photonic crystal cavities achieve strong optical confinement at the expense of large footprints due to extensive surrounding mirrors, whereas whispering-gallery-mode cavities offer high quality factors but suffer from large mode volumes and extreme sensitivity to sidewall roughness. Here, we demonstrate monolithic photonic crystal ring lasers on silicon-on-insulator to combine the advantages of photonic crystal and whispering-gallery-mode cavities. The photonic crystal ring lasers were fabricated from III-V membranes grown on silicon-on-insulator via selective lateral heteroepitaxy and exhibit a compact footprint of 5.51 μm2 (9.50 × 0.58 μm2) and a mode volume of 0.381 (λ/n)3. The devices achieved continuous-wave lasing with a threshold power of 0.27 μW at room temperature and maintained operation with a sub-μW threshold up to 100 °C. Our approach offers a compelling route toward high-density, low-power on-chip light sources for silicon photonics.