Super-Robust Telecommunications Enabled by Topological Half-Supermodes.

Area of Science:

• Photonics
• Condensed Matter Physics
• Integrated Optics

Background:

• Topological photonics offer robust integrated waveguide devices due to backscattering immunity.
• Integration challenges include mode symmetry mismatch and large device dimensions.

Purpose of the Study:

• To overcome integration challenges in topological photonics.
• To develop ultra-compact and seamlessly integrated topological waveguide devices.

Main Methods:

• Introduced a novel valley-ridge gap waveguide based on topological half-supermode engineering.
• Hybridized ridge waveguide modes and valley kink states to create an odd-symmetric supermode.
• Implemented a perfect electric conductor boundary to reduce dimensions and eliminate radiation loss.

Main Results:

• Achieved robust propagation and ultra-compact operation through topological half-supermode engineering.
• Demonstrated seamless integration with standard waveguides via direct transverse electric mode matching.
• Experimental results showed reflection losses below -15 dB and robust signal propagation through sharp bends.

Conclusions:

• Pioneered practical applications of topological half-supermodes for integrated waveguide devices.
• Established a new class of waveguides combining backscattering immunity with deep subwavelength compactness.
• Overcame critical challenges in mode symmetry mismatch and device dimensions for topological photonic integration.