Tamm plasmon Photonic Crystals : from Bandgap Engineering to Defect Cavity

TL;DR

This paper demonstrates the first bandgap engineering of Tamm plasmon photonic crystals with a patterned metallic layer, achieving a tunable, large photonic bandgap and a highly confined defect cavity, opening new avenues in surface mode engineering.

Contribution

It introduces a novel double period design for Tamm plasmon photonic crystals, enabling independent control of bandgap size and spectral position, and demonstrates a single-mode defect cavity.

Findings

Achieved a complete photonic bandgap up to 150 nm in the telecom range.

Demonstrated tunability of bandgap size from 30 nm to 150 nm.

Realized a defect cavity supporting a single highly confined Tamm mode.

Abstract

We report for the first time the bandgap engineering of Tamm plasmon photonic crystals - Tamm plasmon structures of which the metalic layer is periodically patterned into lattice of subwavelength period. By adopting a double period design, we evidenced experimentally a complete photonic bandgap up to $150\,nm$ in the telecom range. Moreover, such design offers a great flexibility to tailor on-demand, and independently, the band-gap size from $30\,nm$ to $150\,nm$ and its spectral position within $50\,nm$. Finally, by implementing a defect cavity within the Tamm plasmon photonic crystal, an ultimate cavity of $1.6\mu m$ supporting a single highly confined Tamm mode is experimentally demonstrated. All experimental results are in perfect agreement with numerical calculations. Our results suggests the possibility to engineer novel band dispersion with surface modes of hybrid metalic/dielectric structures, thus open the way to Tamm plasmon towards applications in topological photonics, metamaterials and parity symmetry physics.