Integrated Fast-light Micro-inertial Sensors for GPS Denied Navigation

ABSTRACT: We propose to develop an all-optical Inertial Measurement Unit (IMU) which achieves high sensitivity to accelerations and rotations in a small package using fast-light enhancement. In an optical IMU, the rotation sensitivity depends on the area enclosed by a circular optical path, so it is impossible to significantly reduce the size of a standard fiber optic gyroscope or ring laser gyroscope without sacrificing sensitivity. However, using the phenomenon of fast light, which we will produce through Stimulated Brillouin Scattering in a fiber, the sensitivity of an optical sensor of a given size and shape can be enhanced by orders of magnitude. Optical accelerometers can likewise be enhanced to high sensitivity using fast-light phenomena. Our approach will allow the construction of gyroscopes and accelerometers from fiber-based components and reliable, efficient telecom-grade lasers. Unlike fast-light methods which use atomic phenomena, our design will not require locking of lasers to specific wavelengths, and will allow freedom in component selection based on cost, efficiency, radiation resistance or other factors. Combined with photonic integrated circuit technologies, this will allow the construction of a rugged, compact, high sensitivity IMU ideal for unmanned aerial vehicles, orbital launch vehicles and spacecraft. BENEFIT: The system will be ideal for unmanned aircraft, with a sensitivity and SWaP that addresses the unique requirements of smaller airframes and autonomous operation. This includes self-guided ordinance and unmanned aerial vehicles, where traditional optical IMU systems are too large to use. The system can be used in the tracking and control of launch vehicles for placing payloads into orbital or sub-orbital trajectories. The reduced SWaP will be very valuable for reducing costs or improving performance. A small, low power inertial measurement device could prove useful on manned or unmanned spacecraft by providing precision inertial feedback during orbital maneuvers or stationkeeping operations. The device could be used to actively stabilize platforms such as for mounted weapons and communications platforms or during sensitive astronomical observations or scientific measurements. Commercial aircraft and marine vessels could benefit from a compact, rugged device, which may prove cost-effective for some applications.