Embodiments herein relate to a process for electron holography image background extraction. A system can comprise a memory that stores, and a processor that executes, computer executable components. The computer executable components can comprise a blurring component that executes a primary blurring action and a secondary blurring action on an original electron holography (EH) image characterized by a set of pixels having a set of original pixel values, and a generating component that generates a set of modified pixel values, for the set of pixels, based on a difference of a set of first pixel values, of the set of pixels, resulting from the primary blurring action and a set of second pixel values, of the set of pixels, resulting from the secondary blurring action.

A lens-less system for holographic imaging or a holographic imaging device is provided. The method/device includes a stationary image sensor to capture an image of a sample illuminated by light from a stationary illumination source. A reference lens-less holographic image may be captured and used as a base line to reduce image artifacts and/or remove noise from the lens-less holographic image. Since real wavefronts produced by a diverging point source are neither perfectly spherical nor planar but a combination of both qualities, theoretical estimates for wavefront reconstruction based on perfectly planar or spherical incident waves cannot be applied accurately. The method/device here provides a solution by performing a calibrated wavefront reconstruction based on equations governing coherent light propagation for both spherical waves and planar waves with a mathematical correlation between numerical magnification and propagation depth to produce accurate three-dimensional details of the object.

An optical measurement system includes a first light source that generates near infrared rays, a silicon-based image sensor, and an optical system including a beam splitter that divides light from the first light source into first light and second light. The optical system records with the image sensor, a first hologram resulting from modulation with second light, of light obtained by illumination of a sample with the first light, the second light being diverging light.

A holographic camera system includes an imaging lens, a polarizer configured to circularly polarize light incident from the imaging lens, a geometric phase lens with a phase delay of /4, and an image sensor configured to replicate an interference pattern through self-interference of light output from the geometric phase.

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.

A particulate matter detection device takes holographic images of flowing particulate matter concentrated by a virtual impactor, which selectively slows down and guides larger particles to fly through an imaging window. The flowing particles are illuminated by a pulsed laser diode, casting their inline holograms on a CMOS image sensor in a lens-free mobile imaging device. The illumination contains three short pulses with a negligible shift of the flowing particle within one pulse and triplicate holograms of the same particle are recorded at a single frame revealing different perspectives of each particle. A deep neural network classifies the particles based on the acquired holographic images. The device was tested using different types of pollen and achieved a blind classification accuracy of 92.91%. This mobile and cost-effective device weighs 700 g and can be used for label-free sensing and quantification of various bio-aerosols over extended periods.

A digital holographic imaging technique, includes iterative steps of: a) through back-propagation to the object coordinate of a hologram field comprising a spatial distribution of amplitude corresponding to the spatial distribution of intensity of the hologram and a spatial distribution of phase, determining an object field involving a spatial distribution of absorption and of phase shift of the imaged object, b) thresholding the values of the spatial distribution of absorption and of phase shift by decreasing the values to below a respective threshold, the thresholds decreasing in each iteration, c) through repropagation of the object field to the hologram coordinate, determining a modified hologram field comprising a modified spatial distribution of amplitude and a modified spatial distribution of phase, d) replacing the spatial distribution of phase of the hologram field with the modified spatial distribution of phase, the spatial distribution of phase shift and of absorption of the imaged object being those of the object field of the last iteration.