Angular selective optical metasurfaces: Fundamentals, progress and applications

Light manipulation over spatial angular dispersion is a fundamental challenge. The advent of metasurfaces promotes the manipulation of electromagnetic waves in the energy-momentum space. By adjusting the spatial dispersion characteristics, metasurfaces can realize diverse angular selective functionalities, which manifest as unique optical effects customized over particular angular ranges and have garnered increasing interest to address growing application demands. This review introduces state-of-the-art developments of angular selective optical metasurfaces, emphasizing the significant breakthroughs realized until now. We start by introducing fundamental design strategies enabling angular dispersion. Then, the recent progress in angular selective optical metasurfaces, i.e., emission, reflection, transmission, and dynamic directional metasurfaces, are systemically overviewed. Subsequently, their diverse applications such as thermal management, information transfer and encryption, imaging and advanced light detection and ranging systems are addressed. Finally, existing challenges, and potential directions are presented with perspectives in the concluding part, aiming to provide guidance for the future development of advanced angular selective optical metasurfaces.