Visual observation of photonic Floquet-Bloch oscillations

Bloch oscillations (BOs), a significant transport phenomenon, have been extensively studied in static systems but remain enigmatic in Floquet systems. This paper proposes a generalization of BOs in photonic Floquet lattices, termed "photonic Floquet-Bloch oscillations" (FBOs), which are rescaled photonic BOs with a period representing the extended least common multiple of the modulation and Bloch oscillation periods. The authors report the first visual observation of FBOs using waveguide fluorescence microscopy. FBOs exhibit unique properties, including fractal spectrum and fractional Floquet tunneling, surpassing existing BOs in Floquet systems. This new transport mechanism offers a novel approach to wave manipulation with potential applications in photonics, condensed matter physics, and quantum physics.

Zhen Zhang, Yuan Li, Xiankai Sun, Xuewen Shu