Our paper on “Magnified imaging based on non-Hermitian nonlocal cylindrical metasurfaces” [1], in collaboration with Andrea Alù’s Group (University of Texas at Austin), has been published in Physical Review B.
We show that a cylindrical lensing system composed of two metasurfaces with suitably tailored non-Hermitian (i.e., with distributed gain and loss) and nonlocal (i.e., spatially dispersive) properties can perform magnified imaging with reduced aberrations. More specifically, we analytically derive the idealized surface-impedance values that are required for “perfect” magnification and imaging and elucidate the role and implications of non-Hermiticity and nonlocality in terms of spatial resolution and practical implementation. For a basic demonstration, we explore some proof-of-principle quasilocal and multilayered implementations and independently validate the outcomes via full-wave numerical simulations. We also show that the metasurface frequency-dispersion laws can be chosen so as to ensure unconditional stability with respect to arbitrary temporal excitations. These results, which extend previous studies on planar configurations, may open intriguing venues in the design of metastructures for field imaging and processing.
@article{IJ123_PRB_95_115114_2017, title = {Magnified imaging based on non-Hermitian nonlocal cylindrical metasurfaces}, author = {Savoia, Silvio and Valagiannopoulos, Constantinos A. and Monticone, Francesco and Castaldi, Giuseppe and Galdi, Vincenzo and Al\`u, Andrea}, journal = {Physical Review B}, volume = {95}, issue = {11}, pages = {115114}, numpages = {13}, year = {2017}, month = mar, publisher = {American Physical Society}, doi = {10.1103/PhysRevB.95.115114} }