Faces in Photonics: Lei Gong, University of Science and Technology of China

The Faces in Photonics series shines a light on scientists, researchers, and educators from all over the world whose work is reshaping the optics and photonics industry.

This month, we feature Lei Gong, a professor of optics at the University of Science and Technology of China (Hefei, China), whose group developed a 3D holography technique that overcomes limitations of currently available digital holography methods to enable more realistic-looking 3D displays.

Laser Focus World: What inspired your work with optics/holograms?

Lei Gong: Humans are always trying to reveal the microscopic world that can’t be seen with the naked eye. Light offers, maybe, the most powerful tool to explore it. Scientists have been peering at the invisible world through microscopes, but when I came to our lab for the first time, I was thrilled to find light can also capture and manipulate microscopic objects—it was amazing. I later found out this is optical tweezers, which was recognized by the 2018 Nobel Prize in Physics. This is why I’m working with optics.

But I encountered a problem when trying to explain to others what we’d observed. How do you present the invisible world in reality? We need a platform to let people see what it looks like. Fortunately, holography offers the best way to deliver exceptional representation of the 3D world around us. Although 3D hologram technology is currently undelivered in reality, we believe it’s coming in the near future.

LFW: Which research areas are you currently most interested in exploring?

Gong: We’re making tools using light so people can use them to better explore the microscopic world. We’re dedicated to developing novel optical trapping and imaging methods and techniques. These optical techniques can help us understand, diagnose, and treat human diseases. So we’re also exploring their biomedical applications.

LFW: Can you describe your work with holograms for us?

Gong: 3D holograms are a technology overpromised by science fiction, but undelivered in reality. In essence, it’s about shaping light fields to reproduce real scenes around us. We’re developing techniques to improve the capability of shaping light. For instance, we recently proposed a method to break the depth control limit of holographic field projections to create more realistic 3D holograms.

LFW: Most intriguing things you’re seeing emerge in optics right now?

Gong: A new frontier of optics that’s caught our attention is complex optics. If you’ve walked on a foggy morning, you know how severely the fog can impair your depth of vision. Fog is composed of small water droplets that scatter visible light—preventing the formation of a clear image. This is similar to the reason we can’t image through deep tissues.

Multiple scattering randomizes the direction of light entering a disordered medium, such as fog or tissues, so the original light fields are scrambled. This is a critical problem for imaging, optical communications, and many other applications. The field of complex optics focuses on providing an improved understanding of light transport within complex media and developing novel optical techniques to overcome the scattering effects in relevant applications.

LFW: Any advice for anyone who wants to do optics/hologram work?

Gong: I’d encourage them to pay attention to the physics underlying optical phenomena—it may help you get a deeper understanding of your work. And try to use a simple sentence to describe your problem or solution—it can help others understand you quickly.

LFW: Favorite thing about your work?

Gong: I enjoy working with young, talented students—especially when we’re trying to address some longstanding problems. We can share ideas and work together to make a difference within the field. In the future, they will go out and do great things to move the world forward.