Key Points
- Researchers achieved precise steering of electron beams using femtosecond lasers and nanopillar-decorated surfaces.
- The method allows narrow, directional electron beams to be adjustable through laser incidence angles.
- The discovery overcomes the limitations of large, expensive accelerators by enabling compact, high-energy electron production.
- Researchers term this breakthrough “plasma nanophotonics,” likening it to coherent antenna arrays emitting directional radiation.
Researchers from the Tata Institute of Fundamental Research (TIFR), Mumbai, in collaboration with the Australian National University (ANU), Canberra, have developed a pioneering technique to steer high-energy electron beams using ultrahigh-intensity femtosecond lasers. The study, published in Laser and Photonics Reviews, marks a significant advancement in beam control for scientific and technological applications.
Electron beams are critical in fundamental science and applications such as medical therapies, imaging, material science, and semiconductor lithography. Traditionally, these beams are produced by large-scale accelerators, which are complex, costly, and inflexible devices that are difficult to modify for varying energy and current regimes.
However, femtosecond lasers have revolutionized this field by enabling the acceleration of electrons to millions and billions of electron volts over significantly shorter distances, between 100 to 1,000 times less than conventional accelerators. While most experiments have used gaseous plasma targets to generate these beams, the electron emission has primarily followed the laser’s direction, limiting their control and flux.
The recent breakthrough overcomes these challenges by introducing solid targets with nanopillar-decorated surfaces. When high-intensity femtosecond lasers interact with these structured surfaces, they generate narrow, directional beams of relativistic electrons, adjustable by controlling the laser incidence angle.
The nanopillar structures enhance local electric fields, leading to higher electron acceleration than conventional planar surfaces. This new method steers electron beams in desired directions and ensures their angular spread remains narrow, even at high laser intensities—previously difficult to achieve.
Another remarkable outcome of this advance is the duration of the electron pulses. Simulations reveal that the pulses are attosecond in length, offering unprecedented precision in time. This opens avenues for highly specialized applications in physics and engineering. The researchers describe this technique as “plasma nanophotonics,” drawing parallels to an array of antennas spaced to emit coherent, directional electromagnetic radiation.
This discovery represents a major leap in compact electron beam generation and control. It offers new possibilities for high-precision applications, making beam technology more accessible and versatile.