Recently, the research team from the Joint Laboratory for High-Power Laser Physics at the Shanghai Institute of Optics and Fine Mechanics, has made a significant breakthrough in the field of ultrafast spatiotemporal light field measurement. The team developed a Spatiotemporal Wavefront Sensor, achieving for the first time single-shot, self-referenced three-dimensional optical field characterization of spatiotemporal wave packets.

Recently, the research team from Shenguang Ⅱ Laser facility at the Shanghai Institute of Optics and Fine Mechanics of the Chinese Academy of Sciences has realized ultra-flat wavefront sensing and measurement based on photon sieve self-interference technology, addressing the challenge of interferometric measurement for weakly distorted wavefronts.

Researchers from SG II facility has made progress in measuring the Power Spectral Density (PSD) of large-gradient wavefronts. The team proposed a wavefront detection method based on knife-edge scanning filtering, which enables precise detection of mid-to-high spatial frequency errors in wavefronts with large gradients.

The research team from SG II facility established a 3D spatiotemporal multi-mode model for multimode lasers, and conducted an in-depth study of the spatiotemporal interactions among these modes. This work enables a quantitative description of the spatiotemporal evolution at any spatial position and temporal slice during light field propagation.

At the Shenguang-II Facility, researchers have innovatively developed an arbitrary temporal pulse shaping technique utilizing optical waveguide four-wave mixing for high-resolution laser pulse control.

Recently, a joint research team from the High Power Laser Physics Joint Laboratory at the Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, collaborating with a team from Harbin Institute of Technology, has achieved anisotropic three-dimensional array beam splitting control at extremely short wavelengths.

The research team innovatively proposed and experimentally validated a nanosecond-scale pulse contrast measurement method based on laser filamentation in water. This technique utilizes nonlinear optical attenuation generated by the laser-matter interaction to effectively protect the photodiode, achieving up to 40-fold attenuation of the main pulse without affecting low-intensity prepulses.

Regarding to the precise measurement and control of time synchronization and carrier-envelope phase difference (ΔCEP) between pulses, a concise optical method based on the phase retrieval of spectral interference and quadratic function symmetry axis was proposed, which could fit to simultaneously measure the time synchronization and ΔCEP between few-cycle pulses. The control precision of our coherent beam combining system can achieve a time delay stability within 42 as and ΔCEP measurement precision of 40 mrad, enabling a maximum combining efficiency of 98.5%. This method can effectively improve the performance and stability of coherent beam combining systems for few-cycle lasers, which will facilitate the obtaining of high-quality few-cycle lasers with high energy.

Researchers from the Shenguang II team at the Joint Laboratory for High Power Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, have developed a novel machine learning-based technique for crystal self-alignment in high-power laser facilities. This method can automatically search for and align the crystal's reflected spot in approximately 10 minutes, significantly enhancing alignment efficiency.

The team discovered a novel phenomenon of dual-peak hot images induced by the cascade effect of nonlinear frequency conversion and self-focusing. Significantly, they uncovered a new principle where beam wavelength conversion causes a rearward shift of the hot image location.