Abstract: The disclosed subject matter relates to a method for determining a three-dimensional particle distribution in a medium, comprising: emitting a coherent light beam to irradiate the sample; recording an interference image of the scattered light beam and a second part of the light beam that has not been scattered; computing, from the interference image, for each one of a plurality of virtual planes lying within the sample, a reconstructed image of the sample, generating for each reconstructed image, a presence image, wherein a value is assigned to each pixel of the presence images if the corresponding pixel of the reconstructed image has an intensity value exceeding a threshold value and if the corresponding pixel of the reconstructed image has a phase value with a predetermined sign.

Abstract: A method for determining a focal length of a particle in a medium, wherein the method comprises: providing a sample; emitting a coherent light beam to irradiate the sample, wherein a first part of the light beam is scattered by the particle; recording an interference image; computing for a set of positions an electric field from the interference image; generating a representation comprising, for each of said positions, an intensity value of the coherent light beam calculated from the computed electric field; finding two positions, a first of which lies in the sample, a second of which lies in the beam direction behind or in front of said first position; and determining the focal length from the two found positions.

Abstract: A method for determining a property of at least one particle (P) in a medium (M), comprising: emitting a coherent light beam (6) to irradiate a sample (5) of the medium (M); recording an interference image (10) of a first part of the light beam (6) scattered by the at least one particle (P) and a second part of the light beam (6) not scattered by particles (P); computing (S1), for positions (13) within the sample (5), an electric field (E1) of the first part from the interference image (10); generating (S2) a representation (16) comprising for each position (13), a phase value (?), determined from the computed electric field (E1) and from an estimated electric field (E2) of the second part, and an intensity value (I), determined from the intensity (I1) of the first part and from the phase value (?); and determining (S3), therefrom, said property.

Abstract: The disclosed subject matter relates to a method for determining a three-dimensional particle distribution in a medium, comprising: emitting a coherent light beam to irradiate the sample; recording an interference image of the scattered light beam and a second part of the light beam that has not been scattered; computing, from the interference image, for each one of a plurality of virtual planes lying within the sample, a reconstructed image of the sample, generating for each reconstructed image, a presence image, wherein a value is assigned to each pixel of the presence images if the corresponding pixel of the reconstructed image has an intensity value exceeding a threshold value and if the corresponding pixel of the reconstructed image has a phase value with a predetermined sign.