Subwavelength Guiding of Terahertz Radiation by Shallowly Corrugated Metal Surfaces

On the Use of Subwavelength Radial Grooves to Support Spoof Surface-Plasmon-Polariton Waves

“…For the particular case of spoof SPPs, where it is desirable to have a high attenuation in short lengths of propagation so as to reduce the depth of the grooves, the employment of radial grooves improves the ability to mimic true SPPs. This issue has also been pointed out through full-wave simulations for trapezoidal grooves [9], [10]. Alternatively, this letter provides an analysis of the radial grooves by deriving a novel dispersion relation, which also has the advantage of decreasing the computational burden of the required simulations.…”

“…Since then, the search for new possibilities to exploit the similarities between grooved metal structures and the true SPPs has been an extremely active area of research [5], [6]. For example, graded rectangular [7], thin rectangular [8], and trapezoidal grooved structures [9], [10], among others, have been proposed. The desirable properties of spoof SPPs include: a) low-frequency operation, which can facilitate dispersion [11]; c) high confinement of the fields, which is proportional to δ =(k 2 −k 2 0 ) −1/2 , with k and k 0 the propagating and space momentum, respectively; d) low dispersion, related to the group velocity and derived also from the dispersion relation; e) preservation of the original boundary, which requires shallow grooves; and f) controllability of the former properties, which means that small variations of the groove dimensions can have a significant impact on the characteristics of the SPP waves.…”

Surface wave manipulation by plasmonic metasurface based on mode resonance

“…Based on this, a series of new THz devices with high performance have been developed and applied in different areas, such as THz sensors [21][22][23] , THz spectrum and imaging detection [24][25][26] , and THz communication 27 . One of the most representative devices is the one-dimensional THz metal grating waveguide, which has been designed and fabricated into different groove shapes, including rectangular, inclined rectangular, trapezoidal, V-shaped, serrated and meniscus grooves [28][29][30][31][32][33][34][35][36][37] . If the surface grating has gradient depth [38][39][40][41][42] , gradient period 43 , and vertical or downward pyramid grooves 44 , it can realize the so-called "trapped rainbow" that has been proved to be a reflection rather than a real EM wave trapping 45,46 .…”

Novel crest‐trough shaped spoof surface plasmon polaritons for low pass filtering applications

“…Higher attenuation in short propagation lengths is desired in SSPP case; hence, employing radial grooves enhances the mimic‐ability of real SPPs with reduced depth (shallow) grooves. References and have already addressed this matter for the trapezoidal grooves by means of full wave simulations. In Reference , radial grooves has been demonstrated as a feasible configuration to efficiently support and confine SSPP with reduced groove depth in comparison to broadly used rectangular groove through analytical derivations.…”