Liquid Crystal Institute Graduate Students Collaborate With Industry and National Laboratories to Develop Advanced Optical Device
Researchers in Professor Philip Bos’ laboratory at Kent State University's Liquid Crystal Institute® and the Lincoln Laboratory at the Massachusetts Institute of Technology (MIT) recently published the results of their collaborative development of advanced liquid crystal devices that can steer a beam of laser light without physical motion.
Steering a beam of laser light is easily done by mechanically shifting the position of a laser. But what if you would like to steer a beam of light without physical motion?
“It would be great if there were a device, like a window, where the direction of a beam of light transmitted by it could be changed by applying a voltage,” says Bos, Ph.D., professor of chemical physics and associate director of the Liquid Crystal Institute in Kent State’s College of Arts and Sciences. “This is desired for many applications, such as surveillance systems and space communications, but it turns out to be very difficult to do.”
Several years ago, Gregory Crawford, a 1991 doctoral graduate of the Liquid Crystal Institute (who is currently president of Miami University in Oxford, Ohio) proposed a radical new approach to this problem for monochromatic light using liquid crystals. His device was based on what is known as the “Pancharatnam Phase,” and was able to show devices with steering up to about 30 degrees with high efficiency.
Recently, Bos’ lab group has been considering how to improve this device to achieve even larger steering angles. A paper recently published in the Optical Society of America’s journal Optics Express shows a device that can change the direction of light to +40 or -40 degrees with remarkably high efficiency, and predicts that angles as large as 60 degrees may be possible. This work, led by Kent State chemical physics graduate student Kun Gao, is a result of his collaboration with fellow graduate students Colin McGinty and HsienHui Cheng, who developed the theory of operation and the design of the device.
The work started as a collaboration with Achintya Bhowmik, Ph.D., vice president and general manager of the Perceptual Computing Group at Intel Corporation, who also serves as an adjunct faculty member at the Liquid Crystal Institute. More recently, the work has continued as a collaboration with MIT’s Lincoln Laboratory, which recently highlighted the collaboration on the home page of the Lincoln Laboratory website. The team at Lincoln includes: Joseph Vornehm, Brian Roberts, Shaun Berry, Harold Payson and Valerie Finnemeyer, a 2016 Liquid Crystal Institute doctoral graduate.