Orbital angular momentum generation in high-Q photonic crystal microrings

In a new article in Nature Communications, we demonstrate how to generate high orbital angular momentum states from a photonic crystal microring while maintaining high cavity quality factors.

Our work involves utilizing a photonic crystal patterning in a microring resonator to eject the naturally high orbital angular momentum states of the ring into free-space. We develop new understanding of how to make sure that this ejection mechanism does not introduce additional loss, so that high resonator quality factors are still possible. This is important for applications, such as in quantum optics and nonlinear optics, where the cavity quality factor promotes light-matter interaction, but coupling into orbital angular momentum states may be desired (e.g., for spatial mode multiplexing). 

This work is a collaboration with colleagues at DTU, MIT, and NIST.