Unlike most new faculty members, Prof. Avinoam (Avi) Zadok recently joined the Technion’s Faculty of Electrical and Computer Engineering at the pinnacle of an impressive career as the head of a groundbreaking research group at a different Israeli university. In fact, after 15 years leading the Fiber-Optics and Integrated Photonic Devices Research Lab at Bar-Ilan University, Prof. Zadok, who is 51, accepted an invitation to join the Technion, and is excited about the prospects offered by his new academic home.
“The Technion, and specifically the Faculty of Electrical Engineering, the Quantum Center and the Solid State Institute, provides research opportunities far beyond what was available at Bar-Ilan. Moving my lab takes a lot of effort and investment, but I am now able to elevate my research to new levels. I’m thrilled to be here!” he reveals.
Prof. Zadok’s new lab will focus on researching the same two main technological platforms as his previous lab at Bar-Ilan: optical fibers and integrated photonic chips. He has been researching fibers for over 20 years, ever since his doctoral studies, and became hooked on the field of integrated photonic chips for light during his post-doc at Caltech. “Most colleagues only work on one of these, but I enjoy both of them so much that it’s hard for me to select just one. For all these years, about half of my group has been working on fiber and the other half on silicon chips. The two parts of the group have been feeding off each other very well for over 15 years,” he confides.
Prof. Zadok has always been interested in the mutual effect between light and sound waves. These two seemingly unrelated physical phenomena are in fact interlinked in complex and useful manners. The study of light and sound interaction is a common thread for much of his work, for both fibers and silicon devices. “Light changes sound and sound changes light, and there is a rich physics of mutual interplay between them,” he notes. “When we use both sorts of waves in the same problem, we can achieve results that light alone can’t provide. We can make measurements and build sensors; and we can process signals better when using both light and sound.”
Both fiber and silicon are among the most universally available and most technologically significant materials – and that is precisely their appeal for Prof. Zadok. “We deliberately chose those supposedly banal platforms. I want to develop principles on materials that everyone uses.”
In the last few years, Prof. Zadok has ventured into quantum sensing using fibers. His goal is to overcome the problem of noise floors which limit the sensors’ accuracy. Typically, lasers are used for measuring, but the sensing community has long questioned whether laser light is in fact the optimal light source. Instead, quantum optics can generate better states of light, referred to as "squeezed states," which can be measured with lower noise levels.
Rather than using special expensive detectors, very low temperatures or exotic materials, Prof. Zadok decided to use what he calls “stupid old fibers.” The initial results of this project, which is carried out in collaboration with Prof. Avi Pe'er from Bar-Ilan University, have been very encouraging. “We used trivial materials and constructed a test bed that generates light with less noise than the laser benchmark. We have results that demonstrate our ability to produce non-classical light with less noise than lasers, using simple fibers and based on our long experience building fiber systems,” he elaborates.
Prof. Zadok looks forward to further developing this field at his new lab at the Technion. “There are wonderful colleagues at the Quantum Center with excellent ideas. We know how to build systems. My hope is to collaborate more and more and absorb more and more knowledge on quantum-related physics and technologies and implement them over our platforms, and also the other way around: to offer these platforms to colleagues. This is already happening and there have already been many exciting discussions with colleagues,” he says.
Eight years ago, Prof. Zadok’s lab solved a riddle which had been confounding scientists for over 50 years: How do you make an optical measurement of something you don’t see, which light doesn’t reach? Their solution was to use optical fibers as ultrasound transfusers. “We don’t need to see, because we can listen. If we can master the combined toolset of light and ultrasound, we can do things that light alone can’t. This was seemingly an optics experiment, but actually it wasn’t – it was an ultrasound experiment,” he elaborates. As a result of this breakthrough, Avi Zadok was made a Fellow of Optica (formerly the Optical Society of America).
Prof. Zadok is an academician par excellence. “For me, the satisfaction lies in doing something the community deemed impossible. That’s enough. I don’t need to make a product. I prefer to move on to the next concept,” he insists, adding, “I enjoy teaching, mentoring, and conceptualizing new ideas.”
During the transition process from Bar-Ilan to the Technion, Prof. Zadok continues to be involved with his former lab while establishing his new laboratory and research group at the Technion. Several of his students from Bar-Ilan have moved to the Technion with him. He already started teaching a course in silicon photonics in the fall semester, a course that is new to the Technion. In the Spring semester, he will also begin teaching the basic class on Electromagnetic Fields to second year undergraduate students.
For now, he continues to live in Givat Shmuel, near Tel Aviv, with his wife and three children. When his youngest daughter finishes high school in two years, the family will consider moving closer to the Technion campus.
“I feel extremely welcomed by colleagues, students, staff and the administration. It is all very exciting,” Prof. Zadok summarizes with a smile.