Faster communication between electronic devices inside a semiconductor chip may be enabled by optical interconnects based on surface-plasmon-polariton (SPP) waves, as their high localization overcomes the size mismatch between optical and electronic devices. Hence, we solved the Maxwell equations in the time domain to investigate the jump of a pulse-modulated carrier SPP wave across a semi-infinite gap on the metallic side of a planar metal/dielectric interface. The Drude model was used for the susceptibility of the metal and the air was taken as the dielectric material in our calculations. The Pearson correlation coefficient of the appropriate component of the Poynting vector at two points on either side of the gap was calculated. After an abrupt termination of the metal, reflection was very low and the signal continued to propagate in air as a precursor followed by a somewhat distorted version of the launched pulse. Information encoded as the existence of a pulse was found to be strongly and positively correlated with the transmitted signal. When the metal/air interface was restored after a gap of width equal to the carrier wavelength in free space, the signal received across the gap still comprised a precursor and a main pulse that were still strongly and positively correlated with the transmitted signal. Thus, information continued to propagate in the forward direction for a long distance after the gap, a promising result for SPP-wave-based optical interconnects.

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Terahertz metasurfaces with pixelated meta-atoms were designed for linearpolarization conversion and absorption. The differences between the two functionalities emerged from the number and arrangement of metal-dielectric combos patching some but not necessarily every pixel of each meta-atom. A patching arrangement for a meta-atom with 3×3 pixels yielded polarization conversion ratio (PCR) > 0.9 over the 10.20-16.08 THz band, whereas another yielded absorptance (A) > 0.9 over the 27.67-28.73 THz band. A third patching arrangement delivered both functionalities, albeit in different spectral regimes: high PCR and high A at 13.92 THz and 29.1 THz, respectively. The spatial profiles of the electric and magnetic fields in each meta-atom suffice to explain the display of these functionalities. The generality of the pixelated meta-atom approach was supported by a meta-atom with 4×4 pixels.

Energy harvesting is expected to be ubiquitous and essential to modern-day life in the future. The limitations of ambient sources, such as thermal, mechanical, and solar, for energy harvesting can be overcome by RF energy harvesting for low-power devices. With the help of perfect metasurface absorbers, an electromagnetic wave can be used as an ambient source for energy harvesting. In this paper, a simple polarization-insensitive triple-band perfect metasurface absorber is proposed for RF energy harvesting applications. The three-layer (metal-dielectric-metal) meta-atom of the designed metasurface consists of a cross-shaped metal patch surrounded by slotted square-shaped metallic patches and of 9 × 9 meta-atoms. The absorber is typically developed in S-and C-bands with resonant frequencies of 3.06, 3.9, and 5.97 GHz. The absorption is near unity which persists over a wide angle of incidence. The experimental results are in close agreement, within 2%, with the simulation results. The reliability of the proposed absorber has been determined for the RF energy harvesting applications, and a high harvesting efficiency of 94.4% and 84% has been observed at 3.07 and 5.97 GHz, respectively.

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