On November 19th, Professor Li Zhengyan and his team at the School of Optical and Electronic Information of HUST built one of the fastest optical field cameras in the world. With an imaging frame rate of 256 trillion frames per second, the “camera”, or compressed optical field topography (COFT), is able to generate a 3D optical field map of a femtosecond laser pulse in a single shot.
In recent years, a large number of time-resolved measurement techniques have been invented in the field of ultrafast optics worldwide, yet the majority of these methods are unable to achieve spatial resolution. The compressed optical field topography invented by Li Zhengyan's team can capture the 2D spatial distribution of the optical field of a femtosecond laser pulse in only one shot, and then characterizes its 3D spatiotemporal distribution.
According to Professor Li, COFT will be used to optimize the processing of laser precision machining equipment in large laser devices and industrial applications. In the future, the team will further improve the technology and enhance cooperation with experts in the field, and hopefully develop spatiotemporal characterization equipment for large-scale laser facilities.
Upon his return to China in 2017, Li Zhengyan began working as a professor at Huazhong University of Science and Technology. “During the early stages of the research, we encountered many challenges. On the one hand, we had to repeat trial and error; on the other hand, we needed to keep accumulating experience as the technology and related algorithms were new to us,” he said.
“At the very beginning, Tang Haocheng and Men Ting, who handled experiments and data processing in the team, were only first-year graduate students. They complained that working on this project was like squeezing water from a stone, because of the steep learning curve. However, with a solid foundation, determination, and firm support, they were eventually able to overcome all the difficulties.”
In the fall of 2021, the compressed optical field topography was initially completed and was used to carry out measurements on plasma ionization front traveling at the speed of light.
Despite all the achievements, Professor Li believes that there are still technical hurdles to be overcome and that the quest for ultra-fast light field cameras is not over. “We have found the right path to our goal, but we still need to work hard in the given direction,” Li Zhengyan said.
Written by: Yu Shiyun
Edited by: Ye Jingyi, Peng Yumeng
Chinese
