All‐Dielectric Metawaveguide Ring Resonators with Deeply Sub‐Diffractive Mode Volumes (Laser Photonics Rev. 19(11)/2025)

Achieving Sub‐diffractive Mode Volumes The cover image illustrates an all‐dielectric meta‐waveguide microring resonator operating below the diffraction limit. Introduction of a subwavelength grating with diamond shaped nanostructures leads to formation of a standing wave and enhanced optical concentration in the nanoscale bridge between diamonds. This reveals a promising approach toward high‐ Q and low‐ V whispering gallery mode resonators. See article 2401579 by Saddam Gafsi and Judson Ryckman for more details.