According to a first aspect, there is provided a method of holographic wavefront sensing, the method including: receiving a light beam, which has a wavefront to be analyzed, on a transparent, flat substrate, which is provided with a lattice of opaque dots, wherein the substrate is arranged above an image sensor; detecting by the image sensor an interference pattern formed by diffracted light, being scattered by the opaque dots, and undiffracted light of the light beam received by the image sensor; processing the detected interference pattern to digitally reconstruct a representation of a displaced lattice of opaque dots, which would form the interference pattern on the image sensor upon receiving the light with a known wavefront; and comparing the representation of the displaced lattice to a known representation of the lattice of opaque dots on the substrate to determine a representation of the wavefront form of the received light beam.

Motility contrast imaging (MCI) is a depth-resolved holographic technique to extract cellular and subcellular motion inside tissue. The holographic basis of the measurement technique makes it highly susceptible to mechanical motion. The motility contrast application, in particular, preferably includes increased mechanical stability because the signal is based on time-varying changes caused by cellular motion, not to be confused with mechanical motion of the system. The use of the resulting spectrogram response signatures, or fingerprint data, of known compounds is disclosed to screen new compounds for leads as to those having potentially beneficial mechanisms of action. The fingerprint data of known toxic compounds can be used to screen new compounds for toxicity.

A method and system for use in reconstruction and retrieval of phase information associated with a two-dimensional diffractive response are presented. The method comprising: providing (75) input data indicative of one or more diffractive patterns corresponding to diffractive responses from one or more objects (50). Dividing (130) said input data into a plurality of one-dimensional slices and determining (140) one-dimensional phase data for at least some of said one-dimensional slices. Tailoring (150) the reconstructed phase data of said one-dimensional slices to form a two-dimensional phase solution. The two-dimensional phase solution is defined by phase shifts of said reconstructed one-dimensional phase data of said one-dimensional slices. The two-dimensional phase solution thus enables obtaining two-dimensional reconstructed phase data suitable for reconstruction of image data (250).

This method for detecting at least one particle in a bodily fluid is carried out via a detection system including a light source, a transparent substrate and a photodetector array, the substrate being positioned between the light source and the photodetector. This method includes the placement of a droplet of bodily fluid on the substrate, the illumination of the droplet via the light source, the acquisition of several successive images of the droplet via the photodetector, each image being formed by radiation transmitted by the illuminated droplet and including at least one elementary diffraction pattern, each elementary diffraction pattern corresponding to waves diffracted by a particle upon illumination of the droplet, the identification, via the acquired images of the mobile elementary diffraction patterns, and the counting of moving particles in the droplet, via the identified mobile elementary diffraction patterns.

The present disclosure provides a system for lens-free imaging that includes a processor in communication with a lens-free imaging sensor. The processor is programmed to operate the imaging sensor to obtain a holographic image and to extract, from the holographic image, a plurality of patches, wherein the plurality of patches is a set of all fixed-size patches of the holographic image. The processor is also programmed to generate a dictionary D comprising a plurality of atoms, wherein the dictionary is generated by solving

[00001]$\underset{,D}{\min }.Math.\underset{i=1}{\overset{N}{.Math.}}.Math.E\left(x_i,D,{}_i\right)+.Math..Math.R\left({}_i\right),$

where N is the number of patches in the plurality of patches, x.sub.i is the i.sup.th patch of the plurality of patches, .sub.i represents the coefficients encoding the i.sup.th patch, E(x.sub.i, D, .sub.i) is a function measuring the squared error of the approximation of x.sub.i by the weighted combination of dictionary elements, and R (.sub.i) is sparsity term.

A method for identifying a state of a cell contained in a sample, including: illuminating the sample using a light source by producing an incident light wave propagating toward the sample; then acquiring, using a matrix-array photodetector, an image of the sample, the sample being placed between the light source and the matrix-array photodetector such that the matrix-array photodetector is exposed to a light wave resulting from interference between the incident light wave and a diffraction wave produced by each cell; applying a numerical reconstruction algorithm to the image acquired by the matrix-array photodetector, to estimate a characteristic quantity of the light wave reaching the matrix-array detector, at a plurality of distances from the matrix-array photodetector. The value of the characteristic quantity, or its variation as a function of distance, allows the state of the cell to be determined from among predetermined states.

Provided is a digital holographic imaging apparatus, comprising: an illumination portion (10) having an illumination light emission surface (32i) for emitting coherent light of a specific wavelength as illumination light toward an object (1) side relative to the illumination light emission surface (32i), and a reference light emission surface (32r) for emitting the coherent light, as reference light, in a direction opposite to the illumination light; and an image sensor (50) located on the reference light emission surface (32r) side of the illumination portion (10) and imaging an interference pattern between object light having been modulated by the object (1) and passed through the illumination portion (10) and the reference light of the illumination light, the image sensor (50) having a pixel array (51) comprising two-dimensionally aligned pixels.

Provided is a digital holographic image-taking apparatus, including: an illumination portion (10) having a light emission surface (14D) for emitting illumination light toward an object (1), the illumination light having a specific wavelength in a coherent plane waveform; and an image sensor (50) having an pixel array (51) including two-dimensionally arranged pixels, the image sensor (50) capturing an interference pattern generated based on the illumination light having acted on the object (1), in which the following conditional expression is satisfied: 0.0000001<Z.sup.2/S<16, where S represents the area of the light emission surface (14D), and Z represents the distance from the light emission surface (14D) to the pixel array (51).

A system and method to produce a hologram of a single plane of a three dimensional object includes an electromagnetic radiation assembly to elicit electromagnetic radiation from a single plane of said object, and an assembly to direct the elicited electromagnetic radiation toward a hologram-forming assembly. The hologram-forming assembly creates a hologram that is recorded by an image capture assembly and then further processed to create maximum resolution images free of an inherent holographic artifact.

Disclosed are optical interrogation apparatus that can produce lens-free images using an optoelectronic sensor array to generate a holographic image of sample objects, such as microorganisms in a sample. Also disclosed are methods of detecting and/or identifying microorganisms in a biological sample, such as microorganisms present in low levels. Also disclosed are methods of using systems to detect microorganisms in a biological sample, such as microorganisms present in low levels. In addition or as an alternative, the methods of using systems may identify microorganisms present in a sample and/or determine antimicrobial susceptibility of such microorganisms.