Real-time halographic interferometry with a pulsed laser and flicker-free viewing

摘要

A system for carrying out holographic interferometry utilizes the same pulsed laser both for the exposure of holograms and for the reconstruction of combined wavefronts resulting from the exposure of a test object to two time spaced laser pulses. This enables the real-time observation of fringes due to interference due to deformation of a test object between timed spaced laser pulses. Pulses used to reconstruct the combined wavefronts are synchronized to the field interval of a video camera associated with a frame grabber so that the combined image may be presented on a video monitor as a continuous flicker-free image. The combined wavefronts may be obtained from separately exposed holograms, from a hologram together with a direct image of an object produced by the same pulse used to reconstruct the hologram, or from a single hologram double exposed by two laser pulses.