Two decades after the first edition of this book in the early nineties, it has seemed timely to prepare a revised version. If the basic design rules of the fiber-optic gyroscope (FOG) have remained unchanged, the technology has certainly matured, and the expectations presented in the first edition have been largely exceeded. For instance, navigation-grade bias stability (0.01 degree/hour) was seen as the goal, when today strategic grade looks accessible with a bias better than 0.0001 degree/hour! Written by one of the field's leading experts, this landmark reference presents a thorough system analysis of the FOG, describing the concepts that have emerged as the preferred solutions for obtaining a practical device. Comprehensive appendixes cover the optics, single-mode fiber optics, and integrated optics necessary to understand the fiber gyro and provide an appropriate vocabulary for communicating with electronic component designers. This new edition also includes 300 figures to ease the understanding of this multidisciplinary system.