Wide-Angle Beamsteering

From OLEG

Contents 1 Funding 2 Project Summary 3 Motivation for Approach 4 Anticipated Benefits 5 Project Publications

Funding

• US Air Force Research Laboratories (AFRL), with Boulder Nonlinear Systems

Project Summary

Controlling an optical system non-mechanically is essential to free space optical communications, remote sensing, and related technologies. We design a compact and two-dimensional beamsteerer that has the ability to scale to large apertures, handles high energy beams and provides fast response without complicating the system design. This beamsteering architecture makes use of liquid crystal assemblies, which are economical to produce.

Motivation for Approach

Electro-optics systems such as lidars greatly enhance the warfighter’s ability to find, recognize and defend against enemy forces. This enhancement is mostly due to the highly directive nature of light, which provides high-resolution sensing. However, the ability to scan highly-directive optical systems over a large field of regard with high accuracy is a difficult mechanical problem, which is normally solved using gimbals. An optical gimbal’s size, weight and power (SWaP) characteristics, mounting requirements and cost make deployment unattractive for many types of platforms. The deployment of gimbal-based systems is especially difficult for small platforms such as satellites and unmanned airborne vehicles (UAVs). To reduce SWaP, mounting requirements and cost, non-mechanical steering techniques are being considered.

Anticipated Benefits

The ability to non-mechanically point an optical system is important in a variety of applications including free space optical communications, remote sensing and weapon guidance. Non-mechanical systems have the potential to be more accurate, smaller, lighter and less expensive than systems that use gimbals to position the beam. Future deployment of optical systems in small airborne or space-based platforms will eventually require these attributes.

Project Publications

• J Kim, MN Miskiewicz, S Serati, and MJ. Escuti, "Demonstration of large-angle nonmechanical laser beam steering based polymer polarization gratings," Proc. SPIE", vol. 8052, 2011.
• J Kim, C Oh, S Serati, and MJ Escuti, "Wide-angle, nonmechanical beam steering with high-throughput utilizing polarization gratings," Applied Optics", 50(14), 2011.
• J Kim, MN Miskiewicz, S Serati, and MJ Escuti, "High efficiency quasi-ternary design for nonmechanical beam-steering utilizing polarization gratings," Proc. SPIE", vol. 7816, 2010.
• C Oh, J Kim, JF Muth, S Serati, and MJ Escuti, "High-Throughput, continuous beam steering using rotating polarization gratings," IEEE Photonics Technology Letters", vol. 22, no. 4, pp. 200-202, 2010.
• C Oh, J Kim, JF Muth, and MJ Escuti, "A new beam steering concept: Risley gratings," Proc. SPIE", vol. 7466, art. no. 74660J, 2009.
• J Kim, C Oh, MJ Escuti, L Hosting, and S Serati, "Wide-angle nonmechanical beam steering using thin liquid crystal polarization gratings," Proc. SPIE, vol. 7093, art. no. 709302, 2008.