Catenaa, Saturday, December 27, 2025-Researchers have developed a two-step method to generate and steer higher-order hyperbolic phonon polaritons, achieving record-quality light–matter waves at the nanoscale.
The international team demonstrated that by exciting fundamental polaritons on a smooth MoO3 crystal atop gold, then scattering them at a sharply defined boundary, the waves convert into higher-order modes with unprecedented travel distance and quality factor.
This approach produces “pseudo-birefringence,” allowing different polariton modes to separate and propagate in distinct directions without altering polarization.
The effect creates a nanoscale traffic controller for light, enabling precise mode routing. Higher-order polaritons, previously difficult to access due to momentum constraints, are now efficiently excited using this method.
The technique holds promise for ultra-compact photonic circuits, on-chip optical filters, and waveplates. Mode-division multiplexing could exploit the separation of polariton modes to transmit multiple data streams along a single nanowaveguide, greatly enhancing information-processing capacity.
Other potential applications include highly sensitive on-chip biosensors and nanoscale optical signal routing.
The research, a collaboration between Shanghai Jiao Tong University, the National Center for Nanoscience and Technology in China, CIC nanoGUNE, and ICFO in Spain, leverages an ultra-smooth, low-loss MoO3 slab to achieve a quality factor of approximately 45.
This represents a new benchmark for nanoscale light–matter wave control.
The study, published in Nature Photonics, highlights the potential for manipulating nanolight with high precision, opening pathways for next-generation photonic technologies, faster optical information processing, and advanced chemical and biosensing applications.
