Wavefront sensing of optical vortices and complex wavefronts.

Wavefront sensing is a non-interferometric, single-shot, and quantitative technique providing the spatial-phase of a beam. The phase is obtained by integrating the gradient of the wavefront. This integration step is especially delicate in the presence of optical vortices, which are topologically stable singular structures that spontaneously appear in wavefields, and that are associated with non-conservative gradient-maps. Unlike incomplete reconstructions typically achieved in such cases, we demonstrate a systematic approach for high-resolution wavefront sensing of complex wavefronts. The method consists in applying an image processing algorithm to the Helmholtz decomposition of the wavevector field. This improvement is expected to benefit to several fields ranging from diffraction tomography to adaptive optics in scattering media.