Tunable Tamm plasmon polaritons in the terahertz range using highly doped InSb as the plasmonic layer

Area of Science:

• Photonics
• Terahertz (THz) Technology
• Materials Science

Background:

• Compact and tunable terahertz (THz) photonic devices are crucial for advanced applications.
• Tamm plasmon polaritons (TPPs) offer a pathway for realizing such devices through photonic-bandgap confinement.

Purpose of the Study:

• To propose and investigate a novel spacer-assisted heterostructure for THz Tamm-state engineering.
• To demonstrate the tunability and potential applications of the proposed structure.

Main Methods:

• Fabrication of a heterostructure comprising a highly doped indium antimonide (InSb) layer and a silicon/TPX distributed Bragg reflector (DBR).
• Numerical investigation of Tamm-type resonance within the DBR stop band.
• Analysis of the effects of carrier concentration, InSb thickness, DBR parameters, and incident angle on resonance characteristics.

Main Results:

• The proposed structure supports a Tamm-type resonance with a significant reflectance dip and strong electric-field confinement.
• Resonance frequency is highly tunable via the carrier concentration in the InSb layer.
• Systematic engineering of resonance position, linewidth, and coupling strength in the THz range is achievable.

Conclusions:

• Highly doped InSb serves as an effective semiconductor plasmonic layer for THz Tamm-state engineering.
• The developed platform is suitable for creating tunable THz filters, narrowband absorbers, and refractive-index sensors.