Sensitivity analysis of phase retrieval from a single defocused intensity measurement

In an optical system, the knowledge of the lens aberrations is required to evaluate the quality of the projected image. Phase retrieval techniques from the focused field can be used for this task but they require multiple through focus measurements and therefore heavy computations. To reduce the computational effort and speed-up the algorithm, we investigate the possibility to perform the phase retrieval using only one intensity measurement plane. Therefore we look for a position of the measurement plane where the phase retrieval computation are optimal. A sensitivity analysis of the uncertainties associated with the phase retrieval parameter is crucial to check the algorithm. The results show that the region close to the focal plane is unsuitable for an acceptable retrieval. By means of this analysis, it is also possible to identify preferable planes in which the retrieval is more effective. Our experimental data confirm the simulation results.