PACK POINTS
Paging Han Solo: A better way to steer laser beams
Steering laser beams is important — just ask Han Solo. NC State engineers have come up with a very energy-efficient way of steering laser beams that is precise and relatively inexpensive.
“In many cases, it is much easier to redirect a laser beam at a target than to steer the laser itself. We intended to develop a way to do this efficiently and without moving anything,” said Dr. Michael Escuti, an associate professor of electrical engineering and co-author of a paper on the research.
The key to the Escuti team’s success was the use of “polarization gratings,” which consist of a thin layer of liquid crystal material on a glass plate. The researchers created a device that allows a laser beam to pass through a stack of these polarization gratings. Researchers manipulated the optical properties of each grating and were able to steer the laser beams by controlling how each individual grating redirects the light.
“Because each individual grating is very good at redirecting light in the desired directions with almost no absorption, the stack of gratings do not significantly weaken the laser power,” Escuti said.
Another advantage of the system is that by adding more gratings, the number of steerable angles increases exponentially. And by using materials and techniques that are already used widely in the liquid crystal display sector, the new method is extremely cost effective.
Potential applications include free space communication, which uses lasers to transfer data between platforms — such as aircraft and soldiers on the battlefield. Technologies such as laser weapons and LIDAR, or laser radar, could also benefit from the research.
Escuti’s team has already delivered prototypes of the technology to the US Air Force. The research was funded by the US Air Force Research Laboratory.
The other co-authors of the paper were former NC State PhD students Jihwan Kim and Chulwoo Oh, along with Steve Serati of Boulder Nonlinear Systems, Inc. 