RING LASER TECHNIQUES FOR ANGULAR ROTATION SENSING,
Abstract
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 seperating the frequencies of the two waves by introduction of nonreciprocal elements into the optical paht are described. Accuracy limitations caused by mechanical instabilities, excitation variations and inherent stimulated emission line width are examined. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1963
- Accession Number
- AD0425706
Entities
People
- D. A. Guidice
- W. L. Harmon