Visual observation of photonic Floquet-Bloch oscillations

Zhen Zhang; Yuan Li; Xiankai Sun; Xuewen Shu

doi:10.1038/s41377-024-01419-z

Visual observation of photonic Floquet-Bloch oscillations

Light Sci Appl. 2024 Apr 28;13(1):99. doi: 10.1038/s41377-024-01419-z.

Authors

Zhen Zhang^#¹, Yuan Li^#², Xiankai Sun³, Xuewen Shu⁴

Affiliations

¹ Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China.
² Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.
³ Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China. xksun@cuhk.edu.hk.
⁴ Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China. xshu@hust.edu.cn.

^# Contributed equally.

Abstract

Bloch oscillations (BOs), an important transport phenomenon, have been studied extensively in static systems but remain mysterious in Floquet systems. Here, by harnessing notions from photonic analogy, we propose a generalization of the existing BOs in photonic Floquet lattices, namely the "photonic Floquet-Bloch oscillations", which refer to rescaled photonic Bloch oscillations with a period of extended least common multiple of the modulation period and the Bloch oscillation period. Next, we report the first visual observation of such photonic Floquet-Bloch oscillations (FBOs) by employing waveguide fluorescence microscopy. Most significantly, the FBOs surpass the existing BOs in Floquet systems and exhibit exotic properties on their own, including fractal spectrum and fractional Floquet tunneling. This new transport mechanism offers an intriguing method of wave manipulation that may contribute to rapidly developing fields in photonics, condensed matter physics, and quantum physics.

Abstract

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