Super Subwavelength Guiding and Rejecting of Terahertz Spoof SPPs Enabled by Planar Plasmonic Waveguides and Notch Filters Based on Spiral-Shaped Units

We numerically simulate novel planar plasmonic waveguides and notch filters with excellent guiding and rejection of terahertz (THz) waves with super subwavelength confinement. Our design is based on spoof surface plasmon polaritons—surface plasmon polaritons with a frequency that has been tuned using patterned conductive surfaces. We find that by using patterns of periodically arranged spiral-shaped units, the dispersion characteristics can be engineered at will by tuning the parameters of the spirals. We find that the resulting plasmonic waveguides have much lower asymptotic frequencies and much tighter terahertz field confinement when compared with conventional rectangular-grooved plasmonic waveguides. We show it is possible to design a structure with lateral dimensions that are only 25% the size of the conventional spoof surface plasmon polariton waveguides but with the same asymptotic frequency. Finally, we combined this architecture with broadband couplers to design an ultrawideband low-pass filter with sharp roll-off (cut-off frequency at 1.29 THz) and low insertion loss (<3 dB). Furthermore, by introducing double ring resonators based on spiral-shaped units, a planar plasmonic notch filter with rejection of more than 17 dB between 0.97 and 0.99 THz is demonstrated. The proposed waveguides and notch filters may have great potential applications in the promising terahertz integrated plasmonic circuits and systems.

[1]  J. Pendry,et al.  Mimicking Surface Plasmons with Structured Surfaces , 2004, Science.

[2]  Tie Jun Cui,et al.  Planar plasmonic metamaterial on a thin film with nearly zero thickness , 2013 .

[3]  Min Qiu,et al.  Slow electromagnetic wave guided in subwavelength region along one-dimensional periodically structured metal surface , 2007 .

[4]  Qing Huo Liu,et al.  Strongly Confined Spoof Surface Plasmon Polaritons Waveguiding Enabled by Planar Staggered Plasmonic Waveguides , 2016, Scientific Reports.

[5]  Bengkang Tay,et al.  Tailoring MoS2 Exciton-Plasmon Interaction by Optical Spin-Orbit Coupling. , 2017, ACS nano.

[6]  Yuehang Xu,et al.  Multipole Modes Excitation of uncoupled dark Plasmons Resonators based on Frequency Selective Surface at X-band Frequency Regime , 2017, Scientific Reports.

[7]  Hao Yu,et al.  An Energy-Efficient and Low-Crosstalk Sub-THz I/O by Surface Plasmonic Polariton Interconnect in CMOS , 2017, IEEE Transactions on Microwave Theory and Techniques.

[8]  S. Kawata,et al.  Surface-Plasmon Holography with White-Light Illumination , 2011, Science.

[9]  D. Gramotnev,et al.  Plasmonics beyond the diffraction limit , 2010 .

[10]  P. Nordlander,et al.  Plasmonic focusing in symmetry broken nanocorrals. , 2011, Nano letters.

[11]  Zhanghua Han,et al.  Spoof surface plasmon-based stripe antennas with extreme field enhancement in the terahertz regime. , 2015, Optics letters.

[12]  W. Barnes,et al.  Surface plasmon subwavelength optics , 2003, Nature.

[13]  S. Kawata,et al.  Plasmonics for near-field nano-imaging and superlensing , 2009 .

[14]  Yong Jin Zhou,et al.  Planar spoof plasmonic ultra-wideband filter based on low-loss and compact terahertz waveguide corrugated with dumbbell grooves. , 2015, Applied optics.

[15]  Tie Jun Cui,et al.  Conformal surface plasmons propagating on ultrathin and flexible films , 2012, Proceedings of the National Academy of Sciences.

[16]  S. R. Andrews,et al.  Highly confined guiding of terahertz surface plasmon polaritons on structured metal surfaces , 2008 .

[17]  Yangyang Chu,et al.  Spoof surface plasmonic waveguide devices with compact length and low-loss , 2017 .

[18]  E. Ozbay.  Plasmonics: Merging Photonics and Electronics at Nanoscale Dimensions , 2006, Science.

[19]  Qiang Cheng,et al.  Broadband and high‐efficiency conversion from guided waves to spoof surface plasmon polaritons , 2014 .

[20]  Xing Zhu,et al.  Plasmonic coupling of bow tie antennas with Ag nanowire. , 2011, Nano letters.

[21]  Stefan A Maier,et al.  Terahertz surface plasmon-polariton propagation and focusing on periodically corrugated metal wires. , 2006, Physical review letters.

[22]  L Martin-Moreno,et al.  Domino plasmons for subwavelength terahertz circuitry. , 2009, Optics express.

[23]  A. Hibbins,et al.  Massively Sub-wavelength Guiding of Electromagnetic Waves , 2014, Scientific Reports.

[24]  Tie Jun Cui,et al.  Broadband amplification of spoof surface plasmon polaritons at microwave frequencies , 2015 .

[25]  Na Liu,et al.  Plasmonic waveguide with folded stubs for highly confined terahertz propagation and concentration. , 2017, Optics express.

[26]  Mark L. Brongersma,et al.  Plasmonics: the next chip-scale technology , 2006 .