Shanghai Institute of Optics and Fine Mechanics has achieved a major breakthrough in the international first ultra strong vortex laser electron direct acceleration experiment

Recently, the research team of the National Key Laboratory of Ultra intense Laser Science and Technology, Shanghai Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, for the first time in the world, verified the feasibility of using relativistic Laguerre Gaussian (LG) lasers to achieve direct laser acceleration (DLA), and successfully generated stable, low emittance, and highly collimated ultrafast electron beams. This progress has broken through the core bottleneck of traditional Gaussian laser direct acceleration technology and opened up a new path for the iterative development of cutting-edge application fields such as micro particle accelerators and high-energy radiation sources. The relevant results were published in Physical Review Letters 137, 025001 (2026) under the title "Experimental Demonstration of Directional and Collimated Electron Acceleration with Hollow Laguerre – Gaussian Lasers".

With the rapid iteration of ultra strong femtosecond laser technology, laser intensity has entered the relativistic level (intensity>10 ¹⁸ W/cm ²). Under such extreme physical conditions, matter will be completely ionized, forming a plasma composed of electrons and ions. Among them, extremely lightweight electrons can be directly accelerated by laser electric fields, a process known as direct laser acceleration (DLA), which is the core foundation of many cutting-edge fields such as advanced accelerators, high-energy radiation sources, laser fast ignition, and attosecond science. Its technological breakthroughs are directly related to the development process of multiple disciplines.

However, for a long time, traditional DLA technology has been plagued by a core challenge: the technology mainly relies on the longitudinal mass driving force of Gaussian laser, but the transverse mass driving force of Gaussian laser follows a Gaussian distribution, which inevitably repels electrons to the side, seriously hindering the stable acceleration of electrons and greatly limiting the pace of DLA technology from laboratory to practical application, becoming a bottleneck problem that troubles related fields.

On the basis of the previous research on ultra strong LG laser generation and driving acceleration, the research team innovatively extended the structured laser field to the field of electronic acceleration experiments. Among them, the Laguerre Gauss (LG) laser, with its unique hollow intensity distribution and intrinsic orbital angular momentum (OAM), provides unprecedented possibilities for precise manipulation of electrons and has become the key to breaking through technological bottlenecks.

The experimental results show that the left circularly polarized LG laser has a unique longitudinal electric field on the optical axis, combined with the transverse field focusing effect, forming a stable "vacuum bubble" acceleration structure - similar to the plasma bubble structure in classical wake field acceleration, providing an excellent environment for stable and efficient acceleration of electrons.

This achievement not only fills the gap in the experimental verification of relativistic LG laser driven DLA, but also breaks through the performance bottleneck of traditional laser acceleration technology, greatly improving the stability and straightness of the electron beam, and laying a solid foundation for the upgrading and iteration of laser acceleration technology. In addition, the acceleration gradient in LG laser field is proportional to the laser intensity and is independent of the complex plasma environment in subsequent stages. This characteristic opens up a new path for manufacturing micro scale acceleration structures, which is expected to bring "micro accelerators" from concept to reality. In the future, with further optimization of technology, this technology is expected to be widely applied in multiple fields such as ultrafast physics, materials science, medical imaging, etc., promoting the leapfrog development of related disciplines.

Quote:Shanghai Institute of Optics and Fine Mechanics has achieved a major breakthrough in the international first ultra strong vortex laser electron direct acceleration experimentShanghai Institute of Optics and Fine Mechanics [citation: July 8, 2026]