<title>Interferometric fiber optic gyro (IFOG) technology achievements at Draper Laboratory</title>

Abstract

Draper Laboratory's experience with Interferometer Fiber Optic Gyro (IFOG) technology started via an Internal Research and Development effort in 1978. This work led to developing fiber optic gyros in which significant advances in IFOG component technologies, assembly, integration, and test were achieved. In excess of 30 patents have been issued to Draper as a result of this pioneering effort. More recently, Draper collaborated with JPL to transition their fiber optic breadboard gyro to a space qualifiable instrument for interplanetary long duration missions. During the initial phase, brassboard gyros were designed and fabricated that demonstrated performance that bettered NASA's CRAF-Cassini spacecraft objectives. In the second phase, the Engineering Model gyro was developed to meet mission qualification tests. Concurrent with this later phase, analysis, tests and qualification activities were performed to validate that gyro components would realize the required 16 year life. Two major inventions (patent pending) were conceived; one provides for continuous adaptive scale factor stability and the other integrates the optical source and photodetector into a single component [Source Integrated Detector (SID)], thereby eliminating a coupler and several splices thus reducing loss by 6 db. Using the above technologies and the implementation of common mode rejection of laser noise, Draper has defined a low noise high performance gyro in which rate power spectral density (PSD) is projected to be < 7 X 10-7 (deg/hr)2/Hz. In those applications, where the PSD < 4 X 10-5 (deg/hr)2/Hz is sought, a small size three component (SID, integrated optics circuit and fiber coil) gyro is easily implemented.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.