4. Conclusion

Dimensional measurements by laser interferometry are widely used for metrological control on machine tools, or during the assembly of large industrial or scientific structures. These methods are based on well-known physical optics principles, in particular the use of Michelson interferometers associated with standard laser components: He-Ne laser sources or laser diodes. The aim of this article is to review the basic principles of interferometric techniques for dimensional measurements, and to illustrate them with a presentation of several commercial solutions. The basic elements of the systems - laser sources and interferometers - were presented, for both homodyne and heterodyne detection, at one and two wavelengths respectively. It can be seen that performance differs according to whether it is possible to measure relative displacement or absolute distance, and whether these measurements...