Photonic Floquet–Bloch Oscillations Dominated by Floquet Gauge

Abstract

Bloch oscillations, a fundamental phenomenon of wave packet revival, are widely used as a powerful tool in precise measurement. The conventional Bloch oscillations exhibit symmetric transport with respect to their half period. Here, a new type of Bloch oscillations (namely, asymmetric Floquet–Bloch oscillations) whose evolution is biased along the evolution dimension is proposed and visually observed. Despite their asymmetric transport, the excited wave packets exhibit perfect revival after propagating over any integer multiples of the Floquet–Bloch oscillation period. This suggests a fundamentally new mechanism of wave packet revival under the half-period evolution of translational antisymmetry. The asymmetric Floquet–Bloch oscillations are experimentally confirmed with direct visualization of their biased light broadening. These findings offer new insights for wave packet revival and can be applied to many rapidly developing fields, including wave controlling, signal processing, and precision metrology.