Patent ID: 11953381
Assignee: SORBONNE UNIVERSITE
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 17:
18. A wavefront sensor for determining wavefront shapes of N spectral channels of a multispectral signal light beam from a single signal image I(x, y) acquisition of said multispectral 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 the incident beams reflect on, or propagate through, the optical mask,
wherein the optical mask is configured with optical properties:
i) to cause the intensity patterns to depend on each of the wavefront shapes, so that a tilt applied to each of the wavefront shapes results in a displacement amount of the said intensity patterns,
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 wavelengths each having a same wavefront shape,
wherein two uncorrelated random intensity patterns are defined as statistically orthogonal relatively to a zero-mean cross-correlation product,
the imaging sensor being configured to record:
(a) reference intensity patterns RL(x, y), each reference intensity pattern of the reference intensity patterns 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 varies from 1 to N, with N being a number of different reference incident monochromatic beams, x and y being coordinates;
b) one single signal image I(x, y) of the intensity patterns generated by the multi-spectral signal light beam which comprises at least the N wavelengths λL configured to reflect on or propagate through the optical mask, the one single signal image I(x, y) being representative of light impinging on the at least one surface area (A);
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 of the reference intensity patterns RL(x, y), at wavelengths λL, for the one single signal image I(x, y),
all N intensity-weight data WLI(x, y) and 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 at least one surface area (A), from the single signal image I(x, y):
a difference DA between the single signal image I(x, y), and sum of the reference intensity patterns RL(x, y) multiplied by the intensity-weight data WLI(x,y) and deformed by the deformation data TLI(x,y) is represented by:, D
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where symbol ∥·∥A designates a norm calculated for all (x, y) sampling points in the at least one surface area (A);
wherein for the at least one surface area (A), each of the reference intensity patterns RL(x,y) are orthogonal to each reference intensity pattern RK(x, y) relatively to the zero-mean cross-correlation product,
when K represents a different incident monochromatic beam other than L and chosen between; and
d) generating data for each of the wavelengths λL representative of:
each of the wavefront shapes by integrating the deformation data TLI(x,y),
an intensity map based on the intensity weight data WLI(x,y).