“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,” says Dr. Michael Escuti, an associate professor of electrical engineering at NC State and co-author of a paper on the research. “We also wanted to be able to steer the beams over a wide range of angles, which is important for practical applications.”
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 says.
Another advantage of the system, Escuti explains, is that “every grating that we add to the stack increases the number of steerable angles exponentially. So, not only can we steer lasers efficiently, but we can do it with fewer components in a more compact system.
“Compared to other laser steering technologies, this is extremely cost-effective. We’re taking advantage of materials and techniques that are already in widespread use in the liquid crystal display sector.”
The technology has a variety of potential applications. For example, free space communication uses lasers to transfer data between platforms – such as between satellites or between an aircraft and soldiers on the battlefield. This sort of communication relies on accurate and efficient laser-beam steering. Other technologies that could make use of the research include laser weapons and LIDAR, or laser radar, which uses light for optical scanning applications – such as mapping terrain.
Escuti’s team has already delivered prototypes of the technology to the U.S. Air Force, and is currently engaged in additional research projects to determine the technology’s viability for a number of other applications.
The paper, “Wide-angle, nonmechanical beam steering with high-throughput utilizing polarization gratings,” was co-authored by Escuti; NC State Ph.D. student Jihwan Kim; former NC State Ph.D. student Chulwoo Oh; and Steve Serati of Boulder Nonlinear Systems, Inc. The paper is published in the journal Applied Optics. The research was funded by the U.S. Air Force Research Laboratory.
NC State’s Department of Electrical and Computer Engineering is part of the university’s College of Engineering.
Note to Editors: The study abstract follows.
“Wide-angle, nonmechanical beam steering with high-throughput utilizing polarization gratings”
Authors: Jihwan Kim, Chulwoo Oh, Michael J. Escuti, North Carolina State University; Steve Serati, Boulder Nonlinear Systems, Inc.
Published: May 1 in Applied Optics
Abstract: We introduce and demonstrate a ternary nonmechanical beam steering device based on Polarization Gratings (PGs). Our beam steering device employs multiple stages consisting of combinations of PGs and Wave Plates (WPs), that allows for a unique three-way (ternary) steering design. Ultra-high efficiency (~ 100%) and polarization sensitive diffraction of individual PGs allow wide steering angles (among three diffracted orders) with extremely high throughput. We report our successful demonstration of the three-stage beam steerer having 44[degree] field-of-regard with 1.7[degree] resolution at 1550 nm wavelength. A substantially high throughput of 78% ? 83% is observed that is mainly limited by electrode absorption and Fresnel losses.
Matt Shipman | EurekAlert!
Dresdner scientists print tomorrow’s world
08.02.2017 | Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS
New technology for mass-production of complex molded composite components
23.01.2017 | Evonik Industries AG
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy