All-fiber 25-level optical storage using double-pulse width modulation for ternary logic operation

All-optical modulation methods for phase-change storage fall into two types: spatially distributed light excitation and guided-wave light excitation. The first modulation method entails a complex optical system. To achieve more than 4 bits of optical storage, guided-wave light excitation often requires a special shape of light pulse or a special waveguide structure. This requires high-precision micro-nano-processing technology, which increases the preparation cost. Therefore, we propose an all-optical memory that combines fibers and phase-change material (PCM) Ge 2 Sb 2 Te 5 (GST). We adopt double-pulse width modulation (DPWM) to achieve 25-level multilevel storage with high repeatability, and the contrast ratio is 56%. The energy of multistage switching is less than 72.2 nJ, and the state can be switched with every change of 0.15 nJ energy. On this basis, we use the three states to realize the three-value logic operation, which is expected to provide a novel construction method for high-speed communication, AI acceleration, quantum technology, and other fields.