Quantifying the Robustness of Topological Slow Light.

Area of Science:

• Photonics
• Condensed Matter Physics
• Nanotechnology

Background:

• Slow light in photonic waveguides enables novel functionalities but is susceptible to scattering losses.
• The backscattering mean free path (ξ) quantifies resistance to imperfections, determining transmission quality.
• Understanding scattering is vital for nanoscale optical device performance.

Purpose of the Study:

• To calculate the backscattering mean free path (ξ) for topological photonic waveguides.
• To investigate the influence of disorder and group index (n_{g}) on ξ.
• To establish criteria for comparing topological and conventional slow-light transport robustness.

Main Methods:

• Theoretical calculation of the backscattering mean free path (ξ).
• Analysis considering specific disorder levels and fixed group index (n_{g}).
• Comparative analysis of topological versus nontopological waveguides.

Main Results:

• The backscattering mean free path (ξ) was determined for topological waveguides under specific conditions.
• Both disorder and group index (n_{g}) significantly impact the robustness of slow light.
• A fixed group index (n_{g}) is essential for meaningful comparisons of ξ.

Conclusions:

• Accurate quantification of slow-light robustness requires considering both ξ and n_{g}.
• Claims of superior performance for topological waveguides must account for these metrics.
• This work provides a framework for evaluating nanoscale slow-light transport.