Observation of Rabi-like Oscillation in a Microwave Photonic-Based Two-Level System

Discrete energy-level dynamics provide a fundamental framework for understanding driven two-state systems. Here, we propose and experimentally demonstrate a classical microwave-photonic analog based on two active fiber loops. Reciprocal electro-optic sidebands coherently couple two independently sustained lasing modes. When the input RF power is increased from 11.7 to 18.7 dBm, the measured oscillation frequency increases from 0.55 to 1.00 MHz, consistent with the modulation-induced coupling predicted by the coupled-mode model. The experiment therefore demonstrates RF-power-controlled Rabi-like oscillation in an active dual-loop system. Because the optical fields and detected intensities are classical, the platform reproduces reduced two-state dynamics rather than quantum-state evolution. This proof-of-concept provides a basis for quantum-inspired microwave-photonic signal processing and future short-cavity implementations.