Abstract
A new phase shift interferometry was developed for precise real time observation of crystal growth both in ground and microgravity conditions. The new signal processor employs an intelligent phase unwrapping technique not only for spatial axis but also time axis. This enables the two dimensional phase distribution and three dimensional surface profile of a crystal to be obtained in real time even in the case that dust or small crystal adsorbed on the surface disturb the phase unwrapping in the previous signal processor.
