Metasurface empowered lithium niobate optical phased array with an enlarged field of view

Integrated optical phased arrays (OPAs) have attracted significant interest to steer laser beams for applications including free-space communications, holography, and light detection and ranging. Although many methods have been proposed to suppress grating lobes, OPAs have also been limited by the trade-off between field of view (FOV) and beamforming efficiency. Here, we propose a metasurface empowered port-selected OPA (POPA), an OPA steered by port selection, which is implemented by an aperiodic waveguide array with an average pitch less than the wavelength and phase controlled by coupling among waveguides. A metasurface layer above the POPA was designed to increase wide FOV steering, aliasing-free by polarization division. As a result, we experimentally demonstrate beam scanning over a +/- 41.04 degrees x 7.06 degrees FOV. The aliasing-free POPA with expanded FOV shows successful incorporation of the waveguide-based OPA technique with an emerging metasurface design, indicating much exploration in concepts for integrated photonic devices. (c) 2022 Chinese Laser Press