Abstract
We propose a paradigm to realize nonreciprocal wavefront engineering using time-modulated gradient metasurfaces. The essential building block of these surfaces is a subwavelength unit cell whose reflection coefficient oscillates at low frequency. We demonstrate theoretically and experimentally that such modulation permits tailoring the phase and amplitude of any desired nonlinear harmonic and determines the behavior of all other emerging fields. By appropriately adjusting the phase delay applied to the modulation of each unit cell, we realize time-modulated gradient metasurfaces that provide efficient conversion between two desired frequencies and enable nonreciprocity by (i) imposing drastically different phase gradients during the up/down conversion processes and (ii) exploiting the interplay between the generation of certain nonlinear surface and propagative waves. To demonstrate the performance and broad reach of the proposed platform, we design and analyze metasurfaces able to implement various functionalities, including beam steering and focusing, while exhibiting strong and angle-insensitive nonreciprocal responses. Our findings open an alternative direction in the field of gradient metasurfaces, in which wavefront control and magnetic-free nonreciprocity are locally merged to manipulate the scattered fields.
| Original language | English (US) |
|---|---|
| Article number | 054054 |
| Journal | Physical Review Applied |
| Volume | 11 |
| Issue number | 5 |
| DOIs | |
| State | Published - May 21 2019 |
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ASJC Scopus subject areas
- Physics and Astronomy(all)
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Nonreciprocal Wavefront Engineering with Time-Modulated Gradient Metasurfaces. / Zang, J. W.; Correas-Serrano, D.; Do, J. T.S.; Liu, X.; Alvarez-Melcon, A.; Gomez Diaz, Juan Sebastian.
In: Physical Review Applied, Vol. 11, No. 5, 054054, 21.05.2019.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Nonreciprocal Wavefront Engineering with Time-Modulated Gradient Metasurfaces
AU - Zang, J. W.
AU - Correas-Serrano, D.
AU - Do, J. T.S.
AU - Liu, X.
AU - Alvarez-Melcon, A.
AU - Gomez Diaz, Juan Sebastian
PY - 2019/5/21
Y1 - 2019/5/21
N2 - We propose a paradigm to realize nonreciprocal wavefront engineering using time-modulated gradient metasurfaces. The essential building block of these surfaces is a subwavelength unit cell whose reflection coefficient oscillates at low frequency. We demonstrate theoretically and experimentally that such modulation permits tailoring the phase and amplitude of any desired nonlinear harmonic and determines the behavior of all other emerging fields. By appropriately adjusting the phase delay applied to the modulation of each unit cell, we realize time-modulated gradient metasurfaces that provide efficient conversion between two desired frequencies and enable nonreciprocity by (i) imposing drastically different phase gradients during the up/down conversion processes and (ii) exploiting the interplay between the generation of certain nonlinear surface and propagative waves. To demonstrate the performance and broad reach of the proposed platform, we design and analyze metasurfaces able to implement various functionalities, including beam steering and focusing, while exhibiting strong and angle-insensitive nonreciprocal responses. Our findings open an alternative direction in the field of gradient metasurfaces, in which wavefront control and magnetic-free nonreciprocity are locally merged to manipulate the scattered fields.
AB - We propose a paradigm to realize nonreciprocal wavefront engineering using time-modulated gradient metasurfaces. The essential building block of these surfaces is a subwavelength unit cell whose reflection coefficient oscillates at low frequency. We demonstrate theoretically and experimentally that such modulation permits tailoring the phase and amplitude of any desired nonlinear harmonic and determines the behavior of all other emerging fields. By appropriately adjusting the phase delay applied to the modulation of each unit cell, we realize time-modulated gradient metasurfaces that provide efficient conversion between two desired frequencies and enable nonreciprocity by (i) imposing drastically different phase gradients during the up/down conversion processes and (ii) exploiting the interplay between the generation of certain nonlinear surface and propagative waves. To demonstrate the performance and broad reach of the proposed platform, we design and analyze metasurfaces able to implement various functionalities, including beam steering and focusing, while exhibiting strong and angle-insensitive nonreciprocal responses. Our findings open an alternative direction in the field of gradient metasurfaces, in which wavefront control and magnetic-free nonreciprocity are locally merged to manipulate the scattered fields.
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U2 - 10.1103/PhysRevApplied.11.054054
DO - 10.1103/PhysRevApplied.11.054054
M3 - Article
VL - 11
JO - Physical Review Applied
JF - Physical Review Applied
SN - 2331-7019
IS - 5
M1 - 054054
ER -