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arXiv · 1710.03797

Wavefront-sensing with a thin diffuser

Pascal Berto·Hervé Rigneault·Marc Guillon
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Abstract

We propose and implement a broadband, compact, and low-cost wavefront sensing scheme by simply placing a thin diffuser in the close vicinity of a camera. The local wavefront gradient is determined from the local translation of the speckle pattern. The translation vector map is computed thanks to a fast diffeomorphic image registration algorithm and integrated to reconstruct the wavefront profile. The simple translation of speckle grains under local wavefront tip/tilt is ensured by the so-called "memory effect" of the diffuser. Quantitative wavefront measurements are experimentally demonstrated both for the few first Zernike polynomials and for phase-imaging applications requiring high resolution. We finally provided a theoretical description of the resolution limit that is supported experimentally.

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Pascal Berto, Hervé Rigneault, Marc Guillon. 2017-10-10. Wavefront-sensing with a thin diffuser. https://doi.org/10.1364/ol.42.005117

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