Ultra-compact all-optical plasmonic switch with triangular resonator and phase-change materials for neuromorphic and advanced optical networks

This paper introduces a highly energy-efficient plasmonic optical switch for the next generation of photonic systems and neuromorphic networks. In this design, the phase-change material Ge₂Sb₂Te₅ (GST) is utilized to enable fully optical signal control without the need for electrical conversion, using an optimized triangular resonator and a nanoscale GST section. This approach increases switching speed, improves efficiency, and reduces signal interference. A key highlight of this structure is the achievement of a very high normalized optical transmission contrast of up to 97.7 % between the amorphous and crystalline phases, which is critical for precise optical switching performance. Additionally, the innovative triangular resonator design and the separate use of two waveguides for control and data paths minimize signal interference and provide precise separation between control and data signals, ensuring fast and accurate operation. The very compact switch footprint (400 × 90 nm) is significantly smaller than comparable devices. Due to the optimized GST dimensions, the switching energy of this device is estimated to be only 8 pJ, minimizing energy consumption. These features make the proposed switch an ideal candidate for synaptic weight adjustment in neuromorphic networks. Detailed simulations based on the Finite Difference Time Domain (FDTD) method further confirm the high potential of this nanophotonic switch to improve optical system performance and reduce energy consumption, making it a promising solution for future technologies.