Single-shot hyperspectral wavefront sensor

A wavefront sensor for determining each wavefront shape of N spectral channels of a multi-spectral signal light beam from a single signal image I(x,y) acquisition of said multi-spectral signal light beam,

• comprising an optical assembly made at least of:
• an optical mask and an 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 said intensity pattern,
• ii) to produce uncorrelated intensity patterns over at least one surface area (A) of the imaging sensor, for a plurality of respective incident monochromatic beams of different wavelength having a same wavefront shape,
• two uncorrelated random intensity patterns being defined as statistically orthogonal relatively to a zero-mean cross-correlation product,
• the imaging sensor recording:
• (a) several reference intensity patterns RL(x,y), each reference intensity pattern RL(x,y) being generated by having a respective reference incident monochromatic beam L with wavelengths λL, reflect on or propagate through the optical mask, L varying from 1 to N, with N being the number of different reference incident monochromatic beams, x and y being coordinates;
• b) one single signal image I(x,y) of the intensity pattern generated by having the multi-spectral signal light beam which comprises at least the N wavelengths λL reflect on or propagate through the optical mask, the single signal image I(x,y) being representative of light impinging on the at least one surface area;
• computing means for:
• c) computing intensity-weight data WLI(x,y) and deformation data TLI(x,y), for all L varying from 1 to N, the intensity-weight data WLI(x,y) and the deformation data TLI(x,y) being representative of an intensity modulation and a diffeomorphism, respectively, of each given reference intensity pattern RL(x,y), at wavelength λL, for the single signal image I(x,y),
• all the N intensity-weight data WLI(x,y) and the N deformation data TLI(x,y) being computed, for L varying from 1 to N, so as to minimize, for all sampling points (x,y) of the surface area A, from the single signal image I(x,y):
• a difference DA between the single signal image I(x,y) on the one hand, and the sum of reference intensity patterns RL multiplied by intensity-weight data WLI(x,y) and deformed by deformation data TLI(x,y), on the other hand:
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• the symbol ∥.∥A designating a norm calculated for all (x,y) sampling points in the surface area A;
• for the surface A, each given reference intensity patterns RL(x,y) being orthogonal to each reference intensity pattern RK(x,y) relatively to the zero-mean cross-correlation product, when K entire natural different from L and chosen between [1;
• N];
• d) generating data for each wavelength λL representative of:
• the shape of the wavefront by integrating the deformation data TLI(x,y),
• the intensity map based on the weight WLI (x,y).