Length and displacement measurement by laser interferometry

The first measurements of length by interferometry were reported by Michelson and Benoit (1895). Limitations of interferometric length and distance measurements with respect to distances involving only a few centimeters disappeared with the development of the laser. Laser interferometry is a fast, accurate measurement technique which has been widely developed and applied to many different metrology problems. Attention is given to lasers, aspects of interference, laser interferometry for length measurement, polarizing interferometers, the determination of flatness and alignment, the refractive index of air, laser interferometry in the standards laboratory, and the conduction of physical measurements which depend on the determination of length, change of length, or displacement.