Nonreciprocal waveguiding structures for THz region based on InSb

Area of Science:

• Terahertz (THz) photonics
• Condensed matter physics
• Plasmonics

Background:

• Surface magnetoplasmons exhibit unique propagation characteristics in magnetized materials.
• Nonreciprocal wave propagation is crucial for developing advanced optical devices.
• Indium antimonide (InSb) is a promising material for THz applications due to its plasmonic properties.

Purpose of the Study:

• To theoretically and numerically investigate surface magnetoplasmons in various THz guiding structures.
• To explore the phenomenon of one-way propagation in these structures under an external magnetic field.
• To identify methods for controlling the bandwidth of unidirectional magnetoplasmon propagation.

Main Methods:

• Theoretical analysis and numerical simulations were employed.
• The Voigt magneto-optic configuration was utilized.
• A 2D numerical technique based on magneto-optic aperiodic rigorous coupled-wave analysis (MOA-RCWA) was developed and applied.

Main Results:

• One-way propagation of surface plasmon polaritons was observed in InSb-based THz waveguides.
• The nonreciprocity of the structures leads to a frequency range supporting unidirectional propagation.
• The one-way bandwidth was shown to be controllable by external magnetic field strength, dielectric permittivity, and waveguide thickness.

Conclusions:

• The studied THz guiding structures support nonreciprocal surface magnetoplasmon propagation.
• The developed MOA-RCWA technique is efficient for analyzing finite-size nanostructured waveguides.
• Tunable one-way bandwidth offers potential for novel THz device applications.