An in-line holographic microscope can be used to analyze a video stream to track individual colloidal particles' three-dimensional motions. The system and method can provide real time nanometer resolution, and simultaneously measure particle sizes and refractive indexes. An assay using the holographic microscope for holographic particle characterization directly detect viruses, antibodies and related targets binding to the surfaces of specifically functionalized micrometer-scale colloidal probe beads. The system detects binding of targets by directly measuring associated changes in the bead's diameter without the need for downstream labeling and analysis.

A digital holographic image-taking apparatus includes an illumination portion having a light emission surface for emitting illumination light toward an object, the illumination light having a specific wavelength in a coherent plane waveform; and an image sensor having an pixel array including two-dimensionally arranged pixels, the image sensor capturing an interference pattern generated based on the illumination light having acted on the object, 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, and Z represents the distance from the light emission surface to the pixel array.

Imaging apparatus and methods using diffraction-based illumination are disclosed. An example apparatus includes a diffraction grating to redirect light from a light source toward a sample to thereby illuminate the sample. The example apparatus also includes an image sensor to detect a diffraction pattern created by the illuminated sample.

There are provided an image processing device and a processing method thereof. The image processing method includes obtaining an interference signal using a sample beam and a reference beam, transforming the interference signal by using a numerical signal processing method or an intensity mixing method to generate a transformed interference signal, and obtaining a three-dimensional (3D) phase image by using the interference signal and the transformed interference signal.

Example embodiments relate to methods and imaging systems for holographic imaging. One embodiment includes a method for holographic imaging of an object. The method includes driving a laser using a current which is below a threshold current of the laser. The method also includes illuminating the object using illumination light output by the laser. Further, the method includes detecting an interference pattern formed by object light, having interacted with the object, and reference light of the illumination light.

A holographic observation method includes: casting a light beam generated by driving a semiconductor laser light source with an electric current with an alternating-current component superimposed or a light beam having a predetermined spectral width and predetermined spectral intensity to have predetermined coherency to an observation object; forming a hologram by causing a light beam transmitted through or reflected by the observation object to interfere with a reference light beam; and obtaining information on the observation object by performing image processing on the hologram.

An optical fiber splitter device comprising at least two optical fibers of different lengths is disclosed for partial or complete compensation of the optical path difference between waves interfering to generate a hologram or an interferogram. Various implementations of this fiber splitter device are described in apparatuses for holographic and interferometric imaging of microscopic and larger samples.

In situ investigation of microbial life in extreme environments can be carried out with microscopes capable of imaging 3-dimensional volumes and tracking particle motion. A lensless digital holographic microscope is disclosed that provides roughly 1.5 micron resolution in a compact, robust package suitable for remote deployment. High resolution is achieved by generating high numerical-aperture input beams with radial gradient-index rod lenses. The ability to detect and track prokaryotes was explored using bacterial strains of two different sizes. In the larger strain, a variety of motions were seen, while the smaller strain was used to demonstrate a detection capability down to micron scales.

This disclosure discloses a method of creating a three-dimensional image of a sample using snapshot optical tomography. The method includes generating a plurality of beams incident on the sample simultaneously, acquiring a field image at a plane not conjugate to the sample plane using off-axis digital holography, extracting amplitude data and phase data for the field image, restoring the sharpness by backpropagating the field image using the extracted amplitude and phase data, acquiring a background image, extracting amplitude data and phase data for the background image, and reconstructing a three-dimensional image of the sample with the backpropagated field image and the background image. The method also includes arranging more than one imaging chains to remove the missing angle artefacts in optical tomography. Also disclosed are systems for performing the method.

A method of imaging a sample having birefringent crystals (or other materials) using a lens-free polarized microscopy device includes illuminating the sample contained on a sample holder with circularly polarized partially coherent or coherent light and capturing lower resolution holographic images of the birefringent crystals with an image sensor. A polarization analyzer unit made from a /4 retarder and a linear polarizer is positioned between the sample holder and the image sensor. The lower resolution holographic images are obtained with the polarization analyzer unit in two different orientations (e.g. 90 orientations). Phase-retrieved, higher resolution images of the birefringent crystals at the different orientations are obtained using the lower resolution holographic images. A differential image is generated from the respective phase-retrieved, higher resolution images. An object support mask is applied to identify the birefringent crystals which can then be pseudo-colored.