Four channel high resolution heterodyne interferometer

Several application-specific laser heterodyne vibrometers are available. In one apparatus, four measurement beams are generated from one laser source, and coupled into single mode fibers for easy positioning on the object. The interferometer allows to measure instantaneous phase relationships between different object points.

For a detailed description:
J.J.J. Dirckx, H.J. van Elburg, W.F. Decraemer, J.A.N. Buytaert and J.A. Melkebeek, ‘Performance and testing of a four channel high resolution heterodyne interferometer’, Optics and Lasers in Engineering 47(3-4), 488-494, 2009.
doi:10.1016/j.optlaseng.2008.05.011