Ultrawide field-of-view integrated optical phased arrays employing multiple orbital angular momentum beams

Optical phased arrays (OPAs) are crucial in beam-steering applications, particularly as transmitters in light detection and ranging and free-space communication systems. In this paper, we demonstrate a on-chip OPA that emits multiple orbital angular momentum (OAM) beams in different directions, each carrying unique topological charges. By superimposing a forked 1×3 Dammann grating on the grating array, six OAM beams with topological charges of ±3, ±4, and ±5 can be radiated from the OPA region. The OPA chip was fabricated on a silicon-on-insulator platform, and the simultaneous generation of multiple OAM beams was realized experimentally. The directions of these vortices can be steered by adjusting the wavelength of the input light and the bias voltages of the phase shifters, enabling a remarkable field of view (FOV) of 140 deg×40 deg within a 120-nm wavelength range. We pave the way for developing systems with ultrawide FOVs, improving the resolution of remote sensing and broadening the possibilities of free-space communications.