Broadband amplification of spoof surface plasmon polaritons at microwave frequencies

Abstract

Efficient amplification of spoof surface plasmon polaritons (SPPs) is proposed at microwave frequencies by using a subwavelength‐scale amplifier. For this purpose, a special plasmonic waveguide composed of two ultrathin corrugated metallic strips on top and bottom surfaces of a dielectric substrate with mirror symmetry is presented, which is easy to integrate with the amplifier. It is shown that spoof SPPs are able to propagate on the plasmonic waveguide in broadband with low loss and strong subwavelength effect. By loading a low‐noise amplifier chip produced by the semiconductor technology, the first experiment is demonstrated to amplify spoof SPPs at microwave frequencies (from 6 to 20GHz) with high gain (around 20dB), which can be directly used as a SPP amplifier device. The features of strong field confinement, high efficiency, broadband operation, and significant amplification of the spoof SPPs may advance a big step towards other active SPP components and integrated circuits.

Hyperbolic spoof plasmonic metasurfaces

“…We believe that the presented metasurface will be promising, for example, in broad applications in spatial multiplexers, focusing and imaging devices, planar hyperlenses, dispersion-dependent directional couplers, and photonic integrated circuits. With the introduction of actively controllable components, 26 one can dynamically tailor the dispersions of the HSPMs and realize the tunable characteristics of spoof SPPs including their propagation and spin. Furthermore, the HSPMs will also be beneficial for building two-dimensional transformation-optics-based devices.…”

“…Recent research on spoof SPPs has revealed their promising potential applications, such as in flexible waveguides, 22 sensors, 23 laser beams, 24 energy concentration 25 and integrated circuits. 26 The concept that underlies spoof SPPs has also been extended to other physical systems, including acoustic waves, and has inspired novel devices in, for example, subwavelength imaging 27 and collimation. 28 Here, we propose and experimentally demonstrate plasmonic metasurfaces with a hyperbolic dispersion where the SPPs propagate on complementary H-shaped, perfectly conducting surfaces at low frequencies.…”

Design, Analysis and Characterisation of Spoof Surface Plasmon Polaritons based Wideband Bandpass Filter at Microwave Frequency

“…The mismatches between simulated and measured results are due to manual fabrication. The transmission loss is marginally higher than that of conventional microstrip line structure because of the mode converter and subwavelength nature of SPP structures 29 . The insertion loss of SSPP filter is approximately same as back to back transition structure, which means the main loss in the SSPP BPF is due to the mode converter 25 .…”

Ultrathin 90-degree sharp bends for spoof surface plasmon polaritons

“…In 2004, Pendry et al suggested that metamaterial structures such as square hole lattices cut into the surface of a perfect electric conductor (PEC) can support bound electromagnetic waves that mimic the dispersion behavior of the SPPs in the optical range [14]. After that, different kinds of structured PEC surfaces, such as the one-dimensional subwavelength corrugations [15,16], dominos [17,18], corrugated metal wires [19,20], complementary split-ring resonator metal films [21], corrugated metal films [22][23][24][25][26][27], etc, have been proposed to support spoof SPPs, showing potential applications in sensing [28,29], laser beams [30], imaging, and directive emission [31]. In particular, spoof SPPs open the possibility of realizing compact waveguiding and focusing devices [32] operating at low frequencies.…”