Liquid crystal point diffraction interferometer (LCPDI) systems that can provide real-time, phase-shifting interferograms that are useful in the characterization of static optical properties (wavefront aberrations, lensing, or wedge) in optical elements or dynamic, time-resolved events (temperature fluctuations and gradients, motion) in physical systems use improved LCPDI cells that employ a "structured" substrate or substrates in which the structural features are produced by thin film deposition or photo resist processing to provide a diffractive element that is an integral part of the cell substrate(s). The LC material used in the device may be doped with a "contrast-compensated" mixture of positive and negative dichroic dyes.
The United States Government has certain rights in this invention pursuant to Cooperative Agreement No. DE-FC03-92SF19460 between the U.S. Department of Energy and the University of Rochester and also Agreement No. NAG3-2348 between the University of Rochester and the National Aeronautics and Space Administration (NASA).