Coherent Interactions in One-Dimensional Topological Photonic Systems and Their Applications in All-Optical Logic Operation

Abstract

Topological photonics has become an active subfield of photonics analogous to the electronic counterpart, and the bulk-edge correspondence leads to robust topologically protected interfacial states. However, a single-topological interface mode with fixed energy cannot be easily manipulated, hindering its applications in optical devices. Here, we study coupled-waveguide arrays mapped to a one-dimensional Su–Schrieffer–Heeger system with two coupled topological interfaces. This configuration greatly increases device versatility and tunability while keeping the confinement of coupled-interface modes inherited from the topological properties nearly intact. Theoretically predicted oscillations between coupled interfaces is experimentally observed. The spatial and energetic isolation of the coupled interface states from the bulk modes is experimentally observed and theoretically confirmed by calculating the degree of localization of the eigenstates, which is found to be comparable to a single-interface state. Finally, a proof-of-principle, all-optical logic circuit is fabricated based on coupled interfaces, demonstrating its potential in assembling on-chip topological optical devices.

Gauge‐Induced Floquet Topological States in Photonic Waveguides

“…For example, the coherent coupling of topological π modes can increase systems versatility and tunability, which has potential in assembling on‐chip topological optical devices. [ 18,57 ]…”

Review on all-optical logic gates: design techniques and classifications – heading toward high-speed optical integrated circuits

“…72 An experimental implementation of AO-OR/XOR gate based on coherent interactions between 1D photonic topological interfaces in coupled waveguide arrays was achieved with unique topological properties, such as efficient confinement, fast switching, and robustness. 73 A recent approach realized the various AO-LGs with high operational speeds utilizing metamaterials-based threedimensional (3D) photonics technology by making suitable variations in diameter of air holes, lattice constant, and effective refractive index of the structure. 74 AO-OR, AND, and XOR gates were fabricated using 3D printing as simple, low-cost solutions to perform AO-logic operations at THz frequency ranges with possibility of reconfiguration to achieve various other logic functions.…”

Artificial gauge induced dispersionless coupling for broadband photonic waveguide integration

“…Tremendous efforts have been made to control the evanescent wave coupling and realize the broadband property. e.g., the adiabatic structures [12][13][14] , inverse design methods [15][16][17][18] , metamaterials [19][20][21][22][23] , and topological designs 24,25 . However, the multiple desired qualities are difficult to reach at the same time, usually, one satisfied performance needs to sacrifice in other important aspects.…”