Measurement of three components of a displacement vector using heterodyne holographic interferometry

A new method for measuring a displacement vector using a single hologram is discussed. The method realizes the measurement by observing the object through three or more points on the hologram using a single lens and by using a heterodyne technique to detect accurate phase differences. In order to establish the optimum optical system of this method, it is necessary to estimate the measuring errors caused by fringe reading error and optical setting error. These two errors are calculated for a typical optical system. On the basis of the results of the analysis, an experimental result was evaluated.