Left: High-resolution transmission electron micrograph of molybdenum disulfide; Right: Comparison of Z scan results of molybdenum disulfide and graphene dispersion Recently, a groundbreaking study led by Professor Wang Jun from the Key Laboratory of High-power Laser Materials at the Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics, has made significant progress in the field of two-dimensional nanophotonics. Alongside collaborators including Zhang Long, Zhao Quanzhong, and Professor Werner Blau from the Chinese Academy of Sciences, the team published an original paper titled "Ultrafast Saturable Absorption of Two-Dimensional MoS2 Nanosheets" in the prestigious journal ACS Nano. The research highlights the exceptional ultrafast saturable absorption properties of two-dimensional MoS2 nanomaterials in the near-infrared range. With the growing interest in graphene and other two-dimensional materials, transition metal sulfides such as MoS2, MoSe2, MoTe2, and WS2 have emerged as promising candidates for next-generation optoelectronic devices. These materials exhibit unique electronic and optical properties when reduced to monolayer structures, making them highly attractive for advanced photonic applications. However, there is still limited understanding of their ultrafast nonlinear optical characteristics, especially for wide-bandgap direct-gap semiconductors like MoS2. The development of high-performance photonic devices plays a crucial role in modern optical information technology. Many key components rely on materials with superior ultrafast nonlinear optical properties. Therefore, in-depth research into these properties is essential for advancing the field of photonics and driving innovation in optical communication and data processing technologies. In this study, the team successfully synthesized high-quality MoS2 nanosheet dispersions using liquid-phase exfoliation. Advanced characterization techniques, including transmission electron microscopy, visible-infrared absorption spectroscopy, Raman spectroscopy, and atomic force microscopy, confirmed the presence of numerous high-quality nanosheets. Ultrafast nonlinear optical experiments demonstrated that MoS2 nanosheets exhibited significantly better saturation absorption performance than graphene when exposed to 100 fs, 800 nm near-infrared laser pulses (see the attached figure). These findings suggest that transition metal sulfide-based two-dimensional semiconductors, such as MoS2, hold great potential for use in various photonic devices, including ultrafast mode-locked lasers, optical limiters, and optical switches. This work was recognized at the Laser Optics 2012 conference in Russia and received special attention at the Graphene 2012 International Conference in Brussels, where it was among the top 20 selected presentations out of nearly 200 applicants worldwide. The research was supported by several key programs, including the "Hundred Talents Program" of the Chinese Academy of Sciences, the National Natural Science Foundation, the Shanghai Municipal Science and Technology Commission's Nano Special Project, the "Pujiang Talents" Program, and the "Outstanding Discipline Leader Program" of Shanghai. This collaborative effort marks a significant step forward in the exploration of two-dimensional nanomaterials for future photonic applications. People Counting,Footfall Analytics For Public Space,Retail Foot Traffic Analysis,People Counting Analysis OP Retail (Suzhou) Technology Co., Ltd , https://www.opretailtech.com