Now You See It, Now You Don’t: How Dr. Moti Fridman Engineers Time-Space Optics

They say that time stops for no man.  But according to one man, time can be made to slow down, creating an effect seemingly plucked from the annals of science fiction: for just a fraction of a second, an event can be rendered invisible.


“Einstein’s theory of relativity is based on the idea that – when you manipulate light – there’s an interchange between time and space,” says Dr. Moti Fridman, a BIU alumnus who trained at the Weizmann Institute then returned to campus after completing a post-doctoral fellowship at Cornell. “Here in our lab, we’re exploring the ways in which temporal and spatial optics can be combined.  Our ultimate goal is to create an entirely new discipline: Time-Space Optics.”


In research that has inspired comparisons to the fictional “invisibility cloak” from the Harry Potter series, Fridman has demonstrated how artful manipulation of laser light can cause a moment in time – along with anything that might be observed during its duration – to disappear in plain sight.


“At Cornell, we passed a laser through a ‘time lens’ – a fiber optic glass with a strong, internal pulse laser,” Fridman explains. “Altering the frequency and wavelength of the laser beam so that it slowed down, then sped up, we created a temporal gap – like the gap created when cars are traveling in a line, and some slow down to let a pedestrian cross. Any event taking place during this gap – which lasts 40 trillionths of a second – happens in a light-free environment and is therefore invisible; in the absence of light, the light scattering that allows events to be seen simply cannot occur.”


Alongside its demonstrated talent for hiding information, this phenomenon – called temporal cloaking – has implications for information sharing, in the all-optical switches envisioned for futuristic computation and communication devices.


“A time lens might allow someone to insert information into a continuous data stream, manipulate it, then reverse everything, all on an ultra-fast time scale,” Fridman says. “We’re still at the early stages, but as we get closer to the limits of current data transfer systems, temporal cloaking might provide a creative solution, both for increasing bandwidth, and for keeping data secure.”


Creative communication is somewhat of a specialty for Fridman, who, as a graduate student, performed in a student theater group and also clocked significant hours behind the wheel of “Mada-Noa” – a mobile science education lab operated by the Weizmann Institute. Not surprisingly, Fridman’s passion for teaching has already been put to use by the BIU Faculty of Engineering, in lectures for potential students.


“A scientist should go out into the world, and to educate the public,” he says. “Not only does this provide payback through public support of our work, it also allows us reach young people who would otherwise have no contact with the university. We create connections that they can build on in the future.”


Fridman – who also holds an appointment at the university’s Bar-Ilan Institute for Nanotechnology and Advanced Materials (BINA) – began building BIU engineering connections while still at Cornell.


“Bar-Ilan is home to Israel’s youngest electro-optics group,” he says, adding that he is looking forward to collaborating with Prof. Zeev Zalevsky – head of the Nano-Photonics Center – as well as the trio of fellow “returning scientist” recruits Drs. Doron Naveh, Dror Fixler and Avi Zadok.  “In a new institution, you have the freedom to do things that might not be possible in a more established academic environment. When I knew I would be coming back to Israel, joining BIU was my highest priority and I was right; I’ve gotten in on the ground floor, and it’s a very exciting place to be.”

For more on Dr. Fridman click here.