Figure 3: Far-field subwavelength focusing.
From: A polychromatic approach to far-field superlensing at visible wavelengths
(a) We emit shaped light pulses (that is, time-varying signals) from eight directions in the far-field region and we map the intensity received in the focal plane, 25 nm on top of the nanorods medium. (b) As a control simulation, we show that we obtain an isotropic diffraction-limited focal spot in free space. In the presence of the plasmonic metalens, we obtain (c) a λ/5 wide spot with the emission of signals that correspond to a time-reversal scheme, and (d) a λ/23 wide spot when emitting signals that correspond to an iterative time-reversal scheme. The colour maps are normalized to the emitted energy.
