Photoinduced modulation of polaritons in MoO3/SiC heterostructures

This study explores the dynamic control of surface phonon polaritons (SPhPs) in a system comprising a van der Waals ultrathin α-MoO3 layer on a 4H-SiC substrate with tunable carrier density via photoinduction (Fig.1 (a)). Unlike previous static modulation techniques, such as geometric adjustments or chemical intercalation, our method utilizes photoinduced doping in the SiC substrate to achieve real-time tunability of SPhP propagation. This dynamic modulation leads to the formation of a polaritonic band gap in the mid infrared range, providing a novel on/off switch for SPhPs and enabling precise control over light transport at the nanoscale. By varying the carrier density in the SiC substrate, we achieve significant enhancements in SPhP canalization, beam confinement, and directionality. Additionally, the ability to generate ultra-slow light through dynamic doping results in a notable increase in the Purcell factor, which is critical for applications in quantum optics and quantum communications. Our findings not only increase the understanding of light-matter interaction in polaritonic crystals but also open up new possibilities for the design and operation of tunable nanophotonic devices. The scalability and compatibility of SiC substrates with existing semiconductor technologies further enhance the practical applicability of our approach. Thus, this work represents a significant step forward in the development of advanced nanophotonic and quantum technologies, demonstrating the potential for innovative applications in tunable optical waveguides, resonators, and enhanced single-photon sources.