Producing a high-power laser that can illuminate a target many meters (or kilometers) away is relatively easy when compared to accurately steering that laser to any desired point in space. Traditional laser beam steering systems (or scanners) are bulky, power-hungry, and vibration-prone mechanical systems. Being able to steer a laser beam from its source to its target quickly, efficiently, precisely, with a minimum amount of hardware, and with high mechanical stability will allow laser scanning—both in transmit and receive modes—to be used almost anywhere (e.g., the outer hull of Navy warships, the wings of aircraft). More specifically, novel, ultra-low size, weight, and power (SWaP) devices for electro-optic laser beam steering are needed.
Solutions that have been explored include microlens arrays, Micro-Electro-Mechanical Systems (MEMS), liquid crystals, holographic glass, and birefringent prisms. All of these approaches suffer from one or more of the following limitations: low throughput, scattering, small steering angle/ aperture, high fabrication cost, and large size/ weight. There is much room for improvement. Bennett Aerospace, in conjunction with North Carolina State University, is developing a solution that will address, and in many cases exceed, all of these limitations along with several additional benefits. Based on novel diffractive optical elements called polarization gratings (PGs), our solution is a non-mechanical, high throughput, wide-angle steerer. Since the technology is embodied into stacks of glass plates and employs commercial materials, similar to LCD TVs and monitors, it has a low-risk potential to scale to larger apertures and be manufactured in low cost in volume. Furthermore, the Bennett Aerospace solution will not require a gimbal-mount, needing only a flat, non-mechanical window for beam transmission.
Our laser beam steering solution will enable fast scanning, eye-safe operation, and high field of regard. Commercial application spaces include medical (eye, cosmetic, surgical systems), optical computing, free-space communications, and lidar systems. Military applications are similarly broad, encompassing surreptitious detection, long-range imaging, night vision, and directed energy systems.