Lasers for Interferometry

The term interferometry comes from the word interference. Interference is a phenomenon that occurs when two waves of any kind come together at the same time and place.
laser_3spaltFig.1: Interference rings for a Michelson interferometer (HeNe laser, 633nm)
Interferometry makes use of interference phenomena for measurement purposes, for example investigation into the flatness of an optical surface. Even though there are many different types of interferometers, all of them basically operate on the same principle. A beam of light comes from a single source and two or more flat mirrors are used to split off different light beams. These beams are then combined so that they interfere with each other. In order to get interference a highly coherent laser source is required. The more coherent the laser beam, or the longer the coherence length, the finer the detail that can be resolved in the interferometer.

All Cobolt DPSS lasers are single longitudinal mode, with coherence lengths >10m, and are thus a very suitable choice of laser for any interferometric application.


See all Cobolt CW Visible 04-01 Series DPSS lasers, CW UV-Visible-NIR 05-01 Series DPSS lasers and ultra-compact 06-01 Series lasers