Progress on New‐Type Optical Thouless Pumping

Abstract Thouless pumping, originally conceptualized as the quantized transport of electrons in a periodic potential, has recently received significant attention in topological photonics. The displacement of the wave in Thouless pumping is governed by the topological invariant known as the Chern number, which emerges from the adiabatic evolution of the potential. In photonic systems, the principles of Thouless pumping enable topologically protected light transport, thereby stimulating growing interest in photonics research. In recent years, numerous novel variants of optical Thouless pumping have emerged that extend beyond the conventional theoretical framework. Notable examples include nonlinear Thouless pumping, non‐Hermitian Thouless pumping, nonAbelian Thouless pumping, and quasi‐periodic Thouless pumping. Moreover, implementations of Thouless pumping are demonstrated across various innovative photonic platforms. This review systematically examines contemporary advancements in optical Thouless pumping, encompassing theoretical underpinnings and experimental implementations.