Tunable Optical Orbital Angular Momentum Beams Generation Using 2D Optical Phased Array with an Ultra‐Large Reconstructed Envelope

Abstract The generation and manipulation of optical vortex beams are essential to optical sensing, communication, and processing applications. The integrated on‐chip generation of vortex beams by the optical phased array (OPA) paves the way of compact, adjustable, and robust optical systems. To address the limited field‐of‐view challenge in 2D architecture OPAs, this work proposes an innovative far‐field envelope reconstruction strategy and implements a grating‐lobe‐free 2D OPA with a bicyclic configuration on a silicon integrated photonic platform. The fabricated device realizes a side‐lobe suppression ratio (SLSR) of ≈11.2 dB, a main lobe full width at half‐maximum (FWHM) of roughly 0.16°, and maintains intensity fluctuations of under 3 dB across even an 80° × 60° steering range, achieving unprecedented ≈187 500 far‐field resolvable points. The high‐performance OPA chip is demonstrated to rapidly generate and steer free‐space vortex beams carrying tunable optical orbital angular momentum (OAM) by accurately calibrating the phase shift and configuring the computed voltage, which provides broad prospects for applications such as optical coherence tomography and high‐capacity optical communications.