A metasurface-based light-to-microwave transmitter for hybrid wireless communications

Signal conversion plays an important role in many applications such as communication,sensing,and imaging.Realizing signal conversion between optical and microwave frequencies is a crucial step to construct hybrid communication systems that combine both optical and microwave wireless technologies to achieve better features,which are highly desirable in the future wireless communications.However,such a signal conversion process typically requires a complicated relay to perform multiple operations,which will consume additional hardware/time/energy resources.Here,we report a light-to-microwave transmitter based on the time-varying and programmable metasurface integrated with a high-speed photoelectric detection circuit into a hybrid.Such a transmitter can convert a light intensity signal to two microwave binary frequency shift keying signals by using the dispersion characteristics of the metasurface to implement the frequency division multiplexing.To illustrate the metasurface-based transmitter,a hybrid wireless communication system that allows dual-channel data transmissions in a light-to-microwave link is demonstrated,and the experimental results show that two different videos can be transmitted and received simultaneously and independently.Our metasurface-enabled signal conversion solution may enrich the functionalities of metasurfaces,and could also stimulate new information-oriented applications.

Light-controllable time-domain digital coding metasurfaces

Programmable metasurfaces enable real-time control of electromagnetic waves in a digital coding manner,which are suitable for implementing time-domain metasurfaces with strong harmonic manipulation capabilities.However,the time-domain metasurfaces are usually realized by adopting the wired electrical control method,which is effective and robust,but there are still some limitations.Here,we propose a light-controllable time-domain digital coding metasurface consisting of a full-polarization dynamic metasurface and a high-speed photoelectric detection circuit,from which the microwave reflection spectra are manipulated by time-varying light signals with periodic phase modulations.As demonstrated,the light-controllable timedomain digital coding metasurface is illuminated by the light signals with two designed time-coding sequences.The measured results show that the metasurface can well generate symmetrical harmonics and white-noise-like spectra,respectively,under such cases in the reflected wave.The proposed lightcontrollable time-varying metasurface offers a planar interface to tailor and link microwaves with lights in the time domain,which could promote the development of photoelectric hybrid metasurfaces and related multiphysics applications.