Inverse-Designed Photonic Crystal Cavities with Controllable Far-Field Numerical Aperture
Researchers developed an inverse design framework to simultaneously optimize photonic crystal cavities for high quality factors and controllable far-field numerical aperture (NA). They designed three distinct L3 cavities with different NAs, achieving a 28-fold improvement in coupling efficiency and a 3.9-fold increase in Q factor over the standard cavity, proving that NA can be tailored using inverse design while remaining robust against fabrication imperfections.