We present an experimental configuration for phase retrieval from a set of intensity measurements. The key component is a spatial light modulator located in the Fourier domain of an imaging system. It performs a linear filter operation that is associated to the process of propagation in the image plane. In contrast to the state of the art, no mechanical adjustment is required during the recording process, thus reducing the measurement time considerably. The method is experimentally demonstrated by investigating a wave field scattered by a diffuser, and the results are verified by comparing them to those obtained from standard interferometry.

In this paper, we present a method to recover the complex amplitude of speckle fields from measurements performed by a shear interferometer. It is based on the optimization of an objective function using the steepest descent gradient technique in combination with a heuristic initial guess. In contrast to already existing methods, the algorithm finds a local minimum least-squares solution even in the presence of Poissonian and Gaussian noise.

We present a shearing interferometer that is based on the birefringent properties of a phase-only spatial light modulator. The main advantages of this approach are the high flexibility, the robustness, and the light efficiency. In contrast to already existing methods the suppression of unwanted diffraction orders is not required.

We report on a method that can be used to improve the result of multiwavelength contouring in the case of objects with rough surface. It is based on the combined evaluation of multiple measurements with varying direction of illumination. While the individual measurements share the same systematics with respect to the shape of the investigated object, the noise arising from speckle decorrelation fluctuates statistically and hence can be reduced by means of averaging. For the case of three illumination directions we show that weighted averaging of the measured phase distributions enhances the signal-to-noise ratio by approximately 3 dB.

We present a method that allows the reconstruction of smooth phase distributions from their laterally sheared representation. The proposed approach is efficient in the sense that only one sheared distribution is needed to completely restore the signal. A mandatory requirement is that the phase distribution is spatially limited. The method is exemplified by means of a synthetic signal, and in addition a practical algorithm is given. Finally, experimental results are presented. The deformation of a metallic surface is investigated by both speckle shearography and electronic speckle pattern interferometry (ESPI) respectively. To give proof of the proposed technique, the phase distribution reconstructed from the shearographic measurement is shown to match the results obtained by the ESPI.