Multiband topological heterojunctions on the surface nanoscale axial photonics platform.

Multiband topological heterojunctions on the surface nanoscale axial photonics platform reveal complex topological phases with up to 21 coupled microresonators.

• Why it matters: Understanding topological phases in photonic systems is crucial for advancing robust optical devices, yet experimental realization of complex multiband heterojunctions remains limited.
• What they did: The team used the Surface Nanoscale Axial Photonics Platform to create and analyze topologically nontrivial SNAP devices, coupling microresonators into SSH lattices and heterojunctions with dissimilar phases, developing new polarization methods.
• The result: This work demonstrates the platform’s potential for simulating topological insulators and paves the way for designing advanced photonic systems with complex topological properties.