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Related Experiment Video

Updated: Aug 28, 2025

Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator

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Published on: January 28, 2019

Frequency-modulated continuous waves controlled by space-time-coding metasurface with nonlinearly periodic phases.

Jun Chen Ke^1,2, Jun Yan Dai^1,2, Jun Wei Zhang^1,2

¹Institute of Electromagnetic Space, Southeast University, 210096, Nanjing, China.

Light, Science & Applications

|September 14, 2022

Summary

This study introduces a new method using space-time-coding metasurfaces (STCMs) to generate and control frequency-modulated continuous waves (FMCWs). This breakthrough enables simultaneous manipulation of FMCW waveforms and their spatial propagation.

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Area of Science:

Electromagnetic Metasurfaces
Waveform Engineering
Applied Physics

Background:

Space-time-coding metasurfaces (STCMs) enable efficient manipulation of electromagnetic waves.
Current STCM research primarily focuses on harmonic generation, with limited control over continuous waveforms.

Purpose of the Study:

To develop a theoretical framework for generating frequency-modulated continuous waves (FMCWs) using STCMs.
To enable simultaneous control over FMCW temporal waveforms and their spatial propagation behaviors.

Main Methods:

Proposed a novel STCM with nonlinearly periodic phases to generate customized time-varying reflection phases.
Utilized monochromatic wave illumination to produce FMCWs based on required time-varying phases.
Encoded the metasurface with different initial phase gradients to control beam propagation directions.

Main Results:

Demonstrated the generation of FMCWs with controllable temporal waveforms and spatial propagation.
Successfully controlled the propagation directions of time-varying beams by adjusting metasurface encoding.
Fabricated a programmable STCM prototype that validated the theoretical predictions.

Conclusions:

The proposed STCM framework effectively generates and controls FMCWs, expanding STCM capabilities beyond harmonic manipulation.
This work offers a new paradigm for dynamic control of complex electromagnetic signals in both time and space.