Inverse-designed Optical Vortex Beam Emitters

We experimentally demonstrate a suite of integrated inverse-designed optical vortex beam emitters. As these emitters are extremely compact, 3 × 3 µm, they are capable of operating over a 60 nm uninterrupted band.

Optical vortex beams and the orbital angular momentum (OAM) they carry are useful in a vast array of applications including classical and quantum communication, super-resolution microscopy, optical trapping and manipulation, and metrology [1]–[3]. While these beams are traditionally generated by phase plates or spatial light modulators, efforts have been made to integrate optical vortex beams emitters onto nanophotonic platforms [4],[5]. Such integration allows for the construction of extremely compact systems, possibly with enhanced performance and additional functionality. Here, we utilize photonic inverse design [6], [7] to create a suite of large-bandwidth miniature optical vortex beam emitters with optical angular momenta spanning −3ℏ to 3ℏ.