Nonreciprocal and time-modulation metasurface for direct imaging
Year: 2024
Type: article
Abstract: Image reconstruction has become more attractive in electromagnetic (EM) areas, especially when metasurface emerges to introduce various methods for manipulating spatial EM waves. Here, we propose a new method for achieving direct EM imaging in the near field by applying a co-aperture active metasurface combined with nonreciprocal and time-modulation features at a single frequency. In our metasurface design, the transmitting and receiving EM signals can be manipulated independently in each meta-atom by integrating the dual-direction power amplifiers (PAs), which can be regarded as isolators for one-way propagation. In the transmitting aperture, a uniform wavefront is realized to illustrate the imaging plane; in the receiving aperture, the phase shift of 360-degree coverage in each meta-atom is dynamically controlled by time-modulation of different frequencies to establish direct relations between the spatial pixels of the imaging plane and spectra of Doppler shift. A metasurface prototype is fabricated, and several targets composed of metal stripes are successfully reconstructed directly with one co-aperture metasurface at a single frequency in experiments. The good measurement results verify the validity of the proposed method for direct imaging and sensing.
Source: Optics Express
DOI: 10.1364/oe.540865
Authors: Yun Bo Li, He Li, Yong Han Liu, Shi Yu Wang, Xian Kun Zeng, Tie Jun Cui
Language: English
Subfield: Aerospace Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,270
Award: G7920607008
OpenAlex ID: W4404674673