Plasmonic Information Carriers: Evolution From Surface Plasmon Polaritons to Nondiffracting Beams and Topological Quasiparticles

ABSTRACT Surface plasmon polaritons (SPPs) are electromagnetic modes propagating along the metal‐dielectric interface. SPPs feature subwavelength‐scale confinement and strong near‐field enhancement, making them promising information carriers for highly integrated nanophotonic chips. However, their intrinsic metal loss and radiation loss associated with interface roughness seriously hinder the transmission performance and application potential in on‐chip interconnect circuits. Nondiffracting modulation and topological manipulation of SPPs have emerged as two parallel research directions to enhance the robustness and capacity of information transmission. With a focus on SPPs as information carriers for highly robust on‐chip optical interconnects, this review starts from conventional SPPs, then moves to nondiffracting SPP beams, and finally proceeds to plasmonic topological quasiparticles. Key advances in multiplexing strategies for multi‐channel SPP routing, directional launching of nondiffracting SPP beams, and modulation of topological quasiparticles are discussed. These advances pave the way toward on‐chip interconnects, ultra‐compact optical routers, and high‐density information storage, providing a new physical foundation for ultra‐compact highly sensitive sensors, super‐resolution imaging, and quantum information processing. To conclude, a perspective on future improvement and research directions is provided.