The sensitivity of the parameter determination from measurements of directly measurable quantities is the Jacobian of the inverse mapping. The Jacobian also detects the ambiguities due to nonconformal mappings by changing its sign. The Jacobian formalism applied to phase-shift interferometry shows that this method does not have ambiguities due to nonconformal mappings and reachs its maximum sensitivity for equidistant phase shifts covering the whole

A new self-calibrating algorithm is described that succeeds in reconstructing an almost error-free wavefront from only three interferograms. The algorithm is based on the assumption that the optical phase, taken modulo 2, is quasi-uniformly distributed in the range [0, 2) over the field of the interferograms. When the actual reference phases differ from those considered in the phase computation program a non-uniform histogram of the computed phase

Based on the metals property of modifying the phase of an incident beam, a simple method for identifying the fast axis of a wave plate independent of a standard retarder is demonstrated.