Patent ID: 6856387

Claim:
A device for determining the intensity and phase of a coherent light beam (F) in a cross-section of the beam, said device comprising: means for measuring intensity Ai (i=1, . . . N) of the beam in N planes, N≧3; based on an initial phase matrix φ 1 corresponding to a plane i=1, calculating means programmed for: calculating complex amplitude matrix B 1 by multiplying the phase matrix e iφ1 by a corresponding amplitude matrix A 1 ; for each plane j>1: calculating a propagated complex matrix B′ j based on the measured amplitude matrix Aj−1 of the plane j−1 and the phase matrix φ of the plane j−1; extracting a phase matrix from the plane j of the matrix B′ j ; iterating the aforesaid calculation by making j=1 when j−1=N, the means for measuring intensity Ai (i=1, . . . N) of the beam in N planes, N≧3, comprising means for forming N distinct elementary beams based on the coherent light beam, characterized in that the means for measuring the intensity Ai (i=1, 2, . . . N) comprise a single detector plane and in that the means for forming N distinct elementary beams comprise means for assembling the N distinct elementary beams on N distinct zones of the single detector plane.