Analysis and Designing the Tunability of Tamm Plasmon Modes
Che-Yuan Chang1*, Yi-Hsun Chen2, Yu-Lin Tsai3, Hao-Chung Kuo3, Kuo-Ping Chen1
1Institute of Imaging and Biomedical Photonic, National Chiao-Tung University, Tainan, Taiwan
2Institute of Lighting and Energy Photonics, National Chiao-Tung University, Tainan, Taiwan
3Department of Photonics and Institute of Electro-Optical Engineering, National Chiao-Tung University, Hsinchu, Taiwan
* presenting author:哲遠張,
Tamm plasmon polaritons are plasmonic resonances excited at the boundary between photonic crystals and metal, in analogy with the electronic Tamm states formed at the boundaries of crystals. Intrigued by the high quality factor and relative low cost in fabrication of Tamm plasmon structures, many studies have revealed the tunability of Tamm plasmon structures, but a design approach remains untouched. In this article a novel design idea based on admittance loci to demonstrate the relation between thin-film structures and the corresponding Tamm plasmon modes is proposed. The tunability of the resonance wavelength and optimization of coupling efficiency was demonstrated by modifying the thickness of structure. Consequently, a shift of resonance wavelength from 584 nm to 497 nm in both simulation and experiment is achieved. Also a reflectance drop adjusted to near zero with a 2.5 times quality factor enhancement was observed in response. In addition, by using different metals to couple Tamm plasmon modes in the visible spectrum, silver has 4.7 times larger quality factor than gold and 84 times larger than aluminum at 700 nm. The near-field enhancement of silver Tamm plasmon modes could be up to 8 times larger than incident electromagnetic waves.

Keywords: plasmon, admittance locus, optical Tamm state, Tamm plasmon