A team of researchers from the University of Ottawa has made significant strides in understanding the ionization of atoms and molecules, a fundamental process in physics that has implications for various fields including x-ray generation and plasma physics.
Take into consideration atoms — the constructing blocks of the whole lot around us. Sometimes, they lose their electrons and turn into charged particles (that is ionization). It happens in lightning, in plasma TVs, and even within the northern lights. Until now, scientists thought they might only control this process in limited ways.
Led by Ravi Bhardwaj, Full Professor at uOttawa’s Department of Physics, and PhD student Jean-Luc Begin, in collaboration with Professors Ebrahim Karimi, Paul Corkum and Thomas Brabec, the research introduces progressive methods to regulate ionization using specially structured light beams.
Ionization is crucial in strong field physics and attosecond science, where it describes how electrons escape from their atomic bonds. Traditionally, it was understood that this process couldn’t be manipulated beyond certain limits. Nonetheless, this recent study challenges that notion.
“We now have demonstrated that by utilizing optical vortex beams — light beams that carry angular momentum — we are able to precisely control how an electron is ejected from an atom,” explains Professor Bhardwaj. “This discovery opens up recent possibilities for enhancing technology in areas equivalent to imaging and particle acceleration.”
The research took place over two years at uOttawa’s Advanced Research Complex. The team found that the handedness and properties of the optical vortex beams significantly affect ionization rates. By adjusting the position of a “null intensity region” inside the beam, they achieved selective ionization, introducing a novel concept called optical dichroism.
Key findings from the research include:
- The primary demonstration of ionization that depends upon the properties of sunshine beams carrying angular momentum.
- Enhanced control over ionization processes that could lead on to advancements in imaging techniques beyond current limitations.
- A brand new understanding of how light will be engineered to influence the behavior of electrons in unprecedented ways.
This work builds upon foundational theories in the sector and has the potential to revolutionize how scientists approach ionization. This is not only for physics textbooks — it could lead on to raised medical imaging, faster computers, and more efficient ways to review materials. It’s especially promising for quantum computing, where controlling individual particles is crucial.
Professor Bhardwaj emphasizes the importance of this breakthrough: “Changing the way in which we take into consideration how electrons are ejected has been difficult, but our research proves that using advanced laser technologies can result in recent discoveries that impact each science and technology.”
