High-mode spoof SPP of periodic metal grooves for ultra-sensitive terahertz sensing

Yao, Haizi and Zhong, Shuncong (2014) High-mode spoof SPP of periodic metal grooves for ultra-sensitive terahertz sensing. Optics Express, 22 (21). pp. 25149-25160. ISSN 1094-4087

[thumbnail of Yao-Zhong-OE-2014-High-mode-spoof-SPP-of-periodic-metal-grooves]
Preview
Text (Yao-Zhong-OE-2014-High-mode-spoof-SPP-of-periodic-metal-grooves)
Yao_Zhong_OE_2014_High_mode_spoof_SPP_of_periodic_metal_grooves.pdf
Accepted Author Manuscript

Download (439kB)| Preview

    Abstract

    We report terahertz surface plasmon resonance (SPR) sensing based on prism-coupling to the spoof surface plasmon polariton (SSPP) mode existing on periodically grooved metal films. It was demonstrated that, except for the fundamental mode of the SSPP, there was also a higher mode SSPP wave when the depth of groove was larger. Both fundamental and high-order modes of SSPP could be used for terahertz sensing. We compared the performance of different modes of SSPP on the sensing sensitivity using both reflection amplitude and phase-jump information. The results indicated that the gap distance between the prism base and the metal film had a significant influence on the reflectivity of SPR sensing by affecting the coupling efficiency of an evanescent wave to an SSPP wave; also, high-order mode SSPP-based sensing had a high sensitivity of up to 2.27 THz/RIU, which nearly doubled the sensitivity of the fundamental mode. The application of high-mode SSPP has enormous potential for ultra-sensitive SPR sensing in the terahertz regime.