Space and Time Modulations of Light with Metasurfaces: RecentProgress and Future Prospects

In this Perspective, we discuss the differentopportunities offered by time-modulated metasurfaces for dynamicwavefront engineering andspace-time photonics. Efforts incodesigning a photonic response while taking into carefulconsideration the switching/tuning mechanisms, including ther-mal, electronic, optical, chemical, and mechanical actuation, areessential for achieving sufficient amplitude, phase, and polarizationmodulation. Here, we examine in detail how the key enablingphotonic technologies currently available and relying on similartuning mechanisms can be applied for the conception of tunablemetasurfaces. We review the latest developments and discuss theadvantages and limitations of each approach, providing the readerwith a clear vision of the current state of the art in activemetasurfaces. We also address the readiness of each technological approach to drawing short- and long-term application perspectives.Finally, we discuss perspectives for spatiotemporal metasurface modulation opening new horizons toward unlimited wavefrontengineering capabilities.

Automated summary

In this Perspective, the authors discuss the opportunities offered by time-modulated metasurfaces for dynamic wavefront engineering and space-time photonics. The authors examine the current state of the art in active metasurfaces and provide a clear vision of the latest developments and limitations. They also discuss the readiness of each technological approach for short- and long-term application perspectives. The authors conclude by discussing the prospects for spatiotemporal metasurface modulation and its potential for unlimited wavefront engineering capabilities.