| Popis: |
The fiber optic gyroscope is now within the high sensitivity predicted by theoretical studies. We review the different steps involved in the progresses realized over the last five years by the various research teams working on this subject around the world. Measurement of rotation rates of 10-2 deg/h have been demonstrated. That corresponds to measurement of phase shift of 10-7 rad in this interferometric system, five orders of magnitude better than the earliest results. The first major breakthrough was the detailled analysis of the effects of fiber birefringence and of mechanical stability of the system, using the fundamental principle of reciprocity of modal propagation. The need for single mode filtering has led to a so-called minimum reciprocal configuration which improves dramatically the sensitivity of the system when it is used in addition of biasing detection techniques. We present the various technological approaches which have been used (bulk optics, all-fiber optics and integrated optics) and we analyse the residual parasitic phenomena which had to be reduced (thermal and acoustic noise, Faraday and optical Kerr effects). Experimental data of an all-fiber system and of a brass board using a single multifunction integrated optic circuit are reported. Finally we discuss the current problems and the future directions of research which should lead to an actual navigation instrument.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. |
