Ultrafast Low‐Loss Optical Logic Gates: Recent Advances in Mechanisms, Materials, Structures and Performance Toward All‐Optical Computing

ABSTRACT Optical logic gates (OLGs) serve as a key technology for overcoming the performance limitations of traditional electronic computing, by utilizing photons for information processing. They offer ultrafast response, low thermal loss, broad bandwidth, and strong resistance to electromagnetic interference, paving the way for next‐generation computing systems. This paper systematically reviews recent advancements in OLGs, focusing on their functions, mechanisms, materials, performance and applications. The paper introduces basic optical operations and discusses three major mechanisms: 1) Photoelectric regulation, including photovoltaic, photoconductive, photogating, and negative photoconductive effect; 2) All‐optical regulation, encompassing linear interference, optical diffraction neural network, nonlinear refractive index modulation, absorption regulation, and frequency conversion; 3) Luminescence regulation, involving various luminescence behaviors such as fluorescence, up‐conversion luminescence, phosphorescence, and chemiluminescence. Regarding material platforms, the paper reviews advanced materials used in OLGs construction, such as chalcogenide glass, two‐dimensional materials, bipolar response materials, phase‐change materials, micro‐nano photonic structures, luminescent materials, as well as organic materials. Furthermore, the paper summarizes the performance of OLGs in terms of on‐off ratio, operation speed, integration level, and energy consumption, and distinguishes their characteristics in different application scenarios. Finally, the potential and future challenges of OLGs in advancing all‐optical information processing technology is explored.