Meet Our Faculty: Prof. Avi Zadok

In the past decade, Prof. Avi Zadok's students have won numerous acclaims. Five of them were included on the Rector's Honor Roll. So how exactly does a research group produce this many shining stars?

Prof. Avi Zadok's students at the Alexander Kofkin Faculty of Engineering at Bar-Ilan University are making a name for themselves. They have won numerous awards and research fellowships, and Prof. Zadok is a proud mentor: "Through the years I have been privileged to work alongside the best of students," he boasts. "Since I established my research group a decade ago, five of my graduate students were awarded the Bar-Ilan University Rector Prize for excellence in graduate studies – four of whom consecutively in the past four years. One of my PhD candidates, Hagai Diamandi, won the Azrieli Fellowship, one of the most esteemed honors bestowed on doctoral fellows in Israel. Another PhD graduate, Dr. Yair Antman, won the Rothschild Post Doctoral Fellowship, and is currently at Columbia University. Since it was established, five PhD candidates and 15 grad students graduated from the group, which now includes one post-doc, seven PhD candidates, one M.Sc. student and a full time lab manager, Dr. Mirit Hen, who holds a PhD in Chemistry. Her knowledge and background complements my own perfectly well. The key component in any research group's success is the quality of its students."

Prof. Avi Zadok, a married father of three, Head of the Fiber Optics and Integrated Photonic Devices Research Lab at the Faculty of Engineering, is beginning his tenth year at the Electro-Optics study track at Bar-Ilan University. He gained his BSc in Physics and Mathematics at the Hebrew University, as part of the IDF's elite Talpiot program, intended for recruits with outstanding academic potentialin the sciences and leadership skills. He then acquired his M.Sc. and Ph.D. in Electrical Engineering at Tel Aviv University, where he studied optical fibers. During his post-doc at Caltech he explored nanotechnology of light. Both these disciplines are incorporated into the projects of his current research group, which focuses on two fields: optical fibers and silicon-photonic chips.

The former field is a classic research discipline, but Zadok's team put a twist on it. Normally, optical fibers are used to transfer information. Team Zadok uses them as environmental measuring sensors: "Although optical fibers were not initially created with this purpose in mind, they have important sensory advantages: they're thin and easy to implement inside various structures. They're long, so they can be used to measure over hundreds of miles, if the case requires. They are suited for aggressive or dangerous environments, where electricity networks are not always an option. Examples for such environments are oil wells or gas tanks. Additionally, optical fibers are weaklyaffected by electrical radiation," says Zadok. "The one major flaw of optical fibers: we can't sense what's happing around it. The fibers are built to preserve the light within them, and not let it trickle outside. If, for example, we wish to measure chemical substances like water or fuel, and produce data about the conditions surrounding the fiber – theoretically, we can't, because the fiber won't allow any light around it. So it's a challenge: how do we see that which we can't see? The answer is – if you can't see, listen."

So how does Zadok's accomplished team "listen" to the fibers? The turned the fibers to an ultrasonic transducer. That is, send ultrasonic waves to the fiber's surroundings, to get an inkling of its conditions. "The light we send into the fibers actually activates ultrasonic sound waves. Those reach the exterior frame of the fiber, and enable us to receive an indirect mapping of the fiber's exterior environment, since we can't 'see' it directly," explains Zadok. "Using this technique, we can lay down miles of fibers, and receive a recurring indication every few yards of what's out there: gas, fuel, sweet water or sea water. This method is potentially applicable to water desalination plants, chemical factories, transportation of fuel and gas, locating leaks or malfunctions of critical infrastructures. We are still at the trial stages in the lab, but we already produced impressive results, which were published in leading journals and attracted much attention."

The second field of study at the lab is silicon chips. "Silicon chips are all around us. They are included in every cell phone, computer, and any electronic appliance. We aim to introduce the handling of light to these chips," says Zadok. "Internet communication utilizes opticalfibers to transfer massive amounts of data. In the past the massive communication was exclusively between lands and continents. Today, however, it is conducted within data centers and servers, and even within the computer itself. Between one component to another. This kind of communication requires optical solutions. This need created the research discipline of Silicon Photonics: the ability to handle optical data within the silicon chip, to handle channels with vast amounts of data, and to route them where they are needed. This field has become one of electro optics key challenges in recent years. We are collaborating on this research with various industry leaders, such as Tower Semiconductors, which is manufacturing chips for us, and with Mellanox Technologies, which develops computer communications at the highest levels. Our research group recently used a silicon chip to process eight channels of optical data. The channels are working in at very tightly-spaced frequencies, closer than ever reported before."

For more info about BIU's Faculty of Engineering click here

Originally posted on the Alexander Kofkin Faculty of Engineering's Winter 2019 Newsletter