Research progress on ultrafast optical switches

As Moore's Law approaches its physical and technological limits, optical switching has emerged as a promising route to overcome the speed bottlenecks of conventional electronics. Ultrafast optical switches, with response times reaching the attosecond scale, hold great potential for next-generation photonic computing and high-speed communication systems. This review summarizes recent progress in ultrafast optical switching, emphasizing advances in materials (e.g., photonic crystals and 2D Mxenes), device architectures (e.g., metasurfaces and waveguides), and switching mechanisms (e.g., nonlinear optical effects and plasmonics). Key performance metrics, including switching speed (picosecond to attosecond), energy efficiency, and contrast, are systematically compared. The review first outlines the primary performance parameters of optical switches, then delves into the underlying quantum dynamics principles and technical approaches enabling ultrafast control. Subsequently, various ultrafast optical switching schemes are categorized and analyzed according to structural characteristics. Through comparisons across multiple parameters, the current research landscape and recent groundbreaking achievements in the field, including attosecond-scale optical modulation and low-loss lithium niobate integrated devices, are highlighted. Finally, future perspectives are discussed from the viewpoints of opto-electro-magnetic synergistic control and heterogeneous integration compatibility. This work aims to provide a comprehensive overview of the field, offering theoretical foundations and technical insights to guide the development of photonic computing chips and advanced optoelectronic technologies.