Engineering the light coupling between metalens and photonic crystal resonators for robust on-chip microsystems

We designed an on-chip transformative optic system with a broadband metalens coupler on foundry compatible silicon photonic platform. By adjusting the metalens’ focusing length and mode dimension, insertion loss between crystal waveguide (PhC WG) structures is reduced to 2 dB by matching focal plane PhC WG mode. Alternatively, integrated allow for direct coupling from multi-mode cavity. The on-resonance transmission in lens–cavity–lens microsystem achieves 60%. These micro-systems do not involve any single-mode nanowire WG, even suspended structure can be mechanically robust against vibrations. proposed new platform miniaturized chemical biosensor applications operating air or solution environments.