Capture me if you can: chasing electrons at light speed with uOttawa’s new Canada Excellence Research Chair

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Portrait of Professor Zenghu Chang
Professor Zenghu Chang, Canada Excellence Research Chair in Attosecond X-ray Photonics at the University of Ottawa.
What if we could see the real-time movement of electrons, those tiniest of particles that power our technology and our lives, in unimaginable detail? For Professor Zenghu Chang, the newly appointed Canada Excellence Research Chair (CERC) in Attosecond X-ray Photonics at the University of Ottawa, this is not a distant dream; it’s an imminent reality that his CERC hopes to soon bring about.

Professor Chang's pioneering work promises to unveil the mysteries of ultrafast electron motion within atoms and molecules, with far-reaching implications in fields ranging from solar cell technology to quantum materials. To understand how fast this motion is, try to imagine something a billion times faster than the blink of an eye.  

Small devices with tremendous impact

Currently, billion-dollar machines the size of football fields are needed to capture these high-speed glimpses. But Professor Chang has a more practical vision: he’s creating the world’s first compact attosecond tender X-ray source. This source would emit X-rays spanning a wide range of energies, allowing scientists to study every element on the periodic table through attosecond X-ray spectroscopy within university laboratories. 

By leveraging high-powered mid-wave infrared (MWIR) lasers, a type of laser that is not yet commercially available, this technology could help unravel the core mechanics of how photochemical reactions occur.  

The ultra-short X-ray flashes generated by MWIR lasers are swift enough to “photograph” electrons in motion. “It’s like turning light into a time machine that reveals the smallest secrets of matter,” says Professor Chang.  

Back Dive by Harold Edgerton
Back Dive by Harold Edgerton (1954) | © The Harold and Esther Edgerton Family Foundation

The stroboscope, a high-speed camera developed by Harold Edgerton in the 1930s, captures a sequence of images of a moving object by illuminating it with brief repetitive flashes of visible light, allowing people to observe the details of athletes’ actions for the first time. In a similar vein, Professor Chang’s compact technology will capture the real-time movement of electrons. 

For brighter and healthier tomorrows

This breakthrough isn’t solely about satisfying scientific curiosity: it could lead to better solar panels, more effective medicines, and higher-speed electronics.  

Here’s a practical example: imagine solar panels that would not only be much more efficient at converting sunlight into energy, but also more cost-effective to produce. This would improve both the quality and the accessibility of renewable energy for everyone, benefitting our homes and our planet. 

Furthermore, this project holds immense potential for creating instruments that could diagnose cancer at its earliest stages and to remove tumors precisely without damaging surrounding healthy tissue. It could revolutionize oncology and bring about safer and more efficient health-care practices.

Meet the chairholder

Recognized globally for his leadership and pioneering work in the fields of ultrafast photonics and attosecond science, the former University of Central Florida researcher has devoted his career to unlocking the mysteries of light and matter. With his CERC appointment, he is poised to push the boundaries of how we see and understand the microscopic world. 

“We're on the verge of a new scientific era, unveiling nature’s most rapid processes,” he says. “It's like upgrading our vision from black-and-white to technicolor.”