Holographic interferometer polychrome and method of display of the variations in optical path in an article by holographic interferometry

摘要

The interferometer includes a first study beam (ER,EB) which is normally red and blue and has a common axis in the measurement volume (E) and the reference beams (RR, RB) have axes which with the respective study beams, define planes that are approximately orthogonal. A slightly angled prismatic plate allows a variable shift between the reference and study beam of each laser and synchronised electronic shutters at each laser allow illumination by each laser at an identical moment. A similarly constructed third beam may be added using a third laser of distinct wavelength. The study and reference beams are orientated relative to each other to avoid the superimposition of parasitics on the useful images on reconstitution of the hologram.