Ring Laser Techniques for Angular Rotation Sensing


Book Description

The concept of using a ''ring'' laser to measure angular rotation is presented. The optical frequencies of the clockwise and the counterclockwise beams traveling around the perimeter of the square ''ring'' depend on their respective optical path lengths which are equal in the absence of rotation. However, angular rotation alters the path lengths, resulting in different frequencies for the two traveling waves. The two waves are optically heterodyned in a photodetector and the resultant beat frequency is directly proportional to the rotation rate of the ''ring.'' An experiment verifying the existence of this phenomenon using a gas laser in the square ''ring'' configuration is described. The physics of mode pulling and various ways to minimize or bypass this problem are discussed in detail. Techniques for artificially separating the frequencies of the two waves by introduction of nonreciprocal elements into the optical path are described. Accuracy limitations caused by mechanical instabilities, excitation variations and inherent stimulated emission line width are examined.




Rotation Sensing with Large Ring Lasers


Book Description

Ring lasers are commonly used as gyroscopes for aircraft navigation and attitude control. The largest ring lasers are sensitive enough that they can be used for high resolution inertial rotation sensing of the Earth in order to detect tiny perturbations to the Earth's rotation caused by earthquakes or global mass transport. This book describes the latest advances in the development of large ring lasers for applications in geodesy and geophysics using the most sensitive and stable devices available. Chapters cover our current knowledge of the physics of the laser gyroscope, how to acquire and analyse data from ring lasers, and what the potential applications are in the geosciences. It is a valuable reference for those working with ring lasers or using the data for applications in geodesy and geophysics; as well as researchers in laser physics, photonics and navigation.










Lasers and Masers


Book Description




Fiber-Optic Rotation Sensors and Related Technologies


Book Description

Currently there is considerable interest in the application of optical meth ods for the measurement of absolute rotation. Active approaches, so-called ring laser gyros, have been under serious development for at least 15 years. More recently, passive approaches using ring resonators or multi turn fiber interferometers have also demonstrated much pro~ise. The only previous conference devoted exclusively to optical rotation sensors, held in 1978 in San Diego, California, was organized by the Society of Photo-optical Instru mentation Engineers(S.P.I.E.J. Although the main emphasis at that conference was on ring laser gyros, a number of papers were also included that described the early development of fiber gyroscopes. Since then the field of fiber optic rotation sensors has grown so rapidly that a conference devoted primarily to this subject was needed. The First International Conference on Fiber-Optic Rotation Sensors was held at the Massachusetts Institute of Technology, Cambridge, Massachusetts, Nove~ ber 9-11, 1981. The purpose of the conference was to bring together the ~any researchers and interested personnel from universities, industry, and govern ment to discuss and exchange ideas on the many recent developments in fiber optic rotation sensors and related technologies. The program consisted of tutorial papers as well as invited and contributed papers.










Sensors, Micro- and Nanosensor Technology


Book Description

Sensors is the first self-contained series to deal with the whole area of sensors. It describes general aspects, technical and physical fundamentals, construction, function, applications and developments of the various types of sensors. This final volume of the series uncovers trends in sensor technology and gives a comprehensive overview of the sensor market. The use of sensors in microsystems and in vacuum microelectronic as well as in acoustic wave devices is discussed. Present and emerging applications of sensors in aerospace, environmental, automotive, and medical industries, among others, are described. This volume is an indispensable reference work for both specialists and newcomers, researchers and developers




Knowing Machines


Book Description

The essays are tied together by their explorations of connections (primarily among technology, society, and knowledge) and by their general focus on modern "high" technology. They also share an emphasis on the complexity of technological formation and fixation and on the role of belief (especially self-validating belief) in technological change.