Centre National De La Recherche Scientifique

Sorbonne Université

Université De Paris

Commissariat a L'energie Atomique Et Aux Energies Alternatives

National Institute of Health and Medical Research

Ecole Polytechnique

Universite Paris Cité

Universite Aix-Marseille

Université´ D'aix-Marseille

Pascal Berto

Marc Guillon

Gilles Tessier

Hervé Rigneault

Esben Ravn Andresen

Tengfei Wu

Dimitris Papadopoulos

A method for reconstructing the wavefront of a light beam by analyzing wavefront-gradient data of said light beam, the light beam containing at least one optical vortex, considering the contribution of the optical vortices to the wavefront. The method including providing a phase-gradient map g of the wavefront of the light beam, generating a Laplacian of a vector potential based on the phase gradient map g, the resulting Laplacian of the vector potential map, called 'Laplacian map', exhibiting peaks, the location of each peak corresponding to the location of an optical vortex and the integral of the peak being proportional to a topological charge n of said optical vortex, computing a singular phase map φbased on the topological charge n and location of each optical vortex, the singular phase φmap being representative of the contribution of the optical vortex.

Reconstruction of a wavefront of a light beam containing optical vortices

A method for determining wavefront shapes of a multi-spectral signal light beam from a single signal image acquisition of said multi-spectral signal beam, with a device including an optical assembly made at least of an optical mask and an imaging sensor, notably a matrix imaging sensor, for generating and recording intensity patterns of incident beams, by having these beams reflect on, or propagate through, the optical mask. The optical mask having the optical properties: i) to cause the intensity pattern to depend on the wavefront shape, so that a tilt applied to the wavefront shape results in a displacement amount of the intensity pattern, and ii) to produce uncorrelated intensity patterns over at least one surface area A of the imaging sensor, for a plurality of respective incident monochrome beams of different wavelengths having a same wavefront shape.

Wavefront sensors and wavefront shape determination using related imaging sensors

A method for determining wavefront shapes of N angular channels Cof different propagation directions P, said propagation directions Pbeing determined by a mean propagation direction vector, from a single signal image acquisition I(x,y) of a multi-angular signal light beam containing said angular channels, each angular channel Ci being separated from other angular channels Cj by an angular separation &#x394;&#x3b1;defined by &#x394;&#x3b1;=arccos, where '&#xb7;' stands for the inner product betweenand.

Method for measuring several wavefronts incoming from different propagation directions

According to one aspect, the invention relates to a device for detecting a resonant non-linear optical signal of Stimulated Raman Scattering (SRS) type induced in a sample. The device comprises electro-optical means for making interact in the sample, at a first modulation frequency, trains of light pulses of angular frequencies &#x3c9;and &#x3c9;and, at a second modulation frequency, trains of light pulses of angular frequencies &#x3c9;and &#x3c9;, such that &#x3c9;&#x2212;&#x3c9;=&#x3c9;&#x2212;&#x3c9;=&#x3a9;where &#x3a9;is a molecular vibrational resonant angular frequency of the sample. Moreover, the device comprises means for synchronous detection at the first and second modulation frequencies of non-linear optical signals resulting from the interaction of the light pulses in the sample, and electronic processing means making it possible to obtain, from electronic signals resulting from the synchronous detection, a signal characterizing the molecular vibrational resonance of the sample.

Device and method for stimulated Raman detection

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Paris, France

Pascal Berto