Metasurfaces – the planarized version of metamaterials – hold the potential of revolutionizing the way we control and mold wave propagation, while largely relaxing typical limitations of bulk metamaterials, especially their sensitivity to losses and fabrication challenges. Early attempts in this direction, however, led to non-ideal designs exhibiting very low efficiency. In a seminal paper [1], I derived fundamental limitations on the possibility of controlling light over an ultrathin surface and, by taking inspiration from the concept of transmit-arrays at RF/microwaves, I proposed a general solution to overcome these limitations and achieve full control of the wave propagation at optical frequencies (figures below). This pioneering work has helped establish the field of metasurfaces, and has stimulated a plethora of subsequent theoretical and experimental works (see, e.g. [2,3]), paving the way for a new paradigm of “flatland nanophotonics” [4,5].
Following this vision, I have also pioneered the possibility of designing metasurfaces to perform a suite of mathematical operations [6,7], which may lead to the realization of ultrathin analog data processors, analog optical computers (potentially very useful for dedicated tasks, such as ultrafast image processing on the hardware level) and equation solving ‘on-the-fly’ as the wave propagates through the structure (figure below).
I am currently working on several exciting new directions in which metasurface concepts can be applied, from advanced wave manipulation and cloaking, to sensing and light trapping, which may have potentially disruptive impact in several diverse areas, from microwave engineering and acoustics, to near-field optics, biology and medicine.
Related Publications:
[1] F. Monticone, N. Mohammadi Estakhri, and A. Alù, “Full Control of Nanoscale Optical Transmission with a Composite Metascreen,” Physical Review Letters, Vol. 110, No. 20, 203903 (5 pages), May 14, 2013. (web) [This paper has been selected as PRL Editor’s suggestion; Press coverage by Phys.org].
[2] F. Qin*, L. Ding*, L. Zhang*, F. Monticone*, C. C. Chum, J. Deng, S. Mei, Y. Li, J. Teng, M. Hong, S. Zhang, A. Alù, and C. W. Qiu, “Hybrid bilayer plasmonic metasurface efficiently manipulates visible light,” Science Advances, in press, 2015. * Joint first authorship
[3] X. Ding*, F. Monticone*, K. Zhang, L. Zhang, D. Gao, S. N. Burokur, A. de Lustrac, Q. Wu, C. W. Qiu, and A. Alù, “Ultrathin Pancharatnam-Berry Metasurface with Maximal Cross-Polarization Efficiency,” Advanced Materials, Vol. 27, No. 7, pp. 1195–1200, February 18, 2015. (web) * Joint first authorship
[4] F. Monticone, and A. Alù, “Metamaterial-Enhanced Nanophotonics,” OPN – Year in Optics, Vol. 24, No. 12, p. 35, November 26, 2013. (web)
[5] F. Monticone, and A. Alù, “Metamaterials and Plasmonics: From Nanoparticles to Nanoantenna Arrays, Metasurfaces and Metamaterials,” Chinese Physics B, Vol. 23, No. 4, 047809, March 20, 2014 (invited review paper). (web) [This paper was the most downloaded CPB paper in 2014]
[6] A. Silva*, F. Monticone*, G. Castaldi, V. Galdi, A. Alù, and N. Engheta, “Performing Mathematical Operations with Metamaterials,” Science, Vol. 343. No. 6167, pp. 160-163, January 10, 2014. (web) [A Perspective from A. Sihvola has appeared on the same issue, pp. 144-145; News highlights have appeared on Phys.org, Nanowerk, AzoNano, Laser Focus World, Tech Times, The Alcalde, La Repubblica, New Scientist, Live Science, ANSA, Penn Current, UT News, among others]. * Joint first authorship
[7] A. Silva, F. Monticone, G. Castaldi, V. Galdi, A. Alù, and N. Engheta, “Doing Math with Light,” Optics and Photonics News, Year in Optics 2014, Vol. 25, No. 12, p. 52, December 1, 2014. (web)