The invention relates to a method for observing a fluorescent sample (10), lying in a plane (P.sub.10), called the sample plane, the sample comprising a fluorescent agent (10f) able to emit a fluorescence light wave (.sub.f), in a fluorescence spectral band (.sub.f), when it is illuminated by an excitation light wave (.sub.e), in an excitation spectral band (.sub.e), the method comprising the following steps: a) illuminating the sample (10) using a first light source (11), in a first illumination spectral band (.sub.1), in the excitation spectral band (.sub.e0, and acquiring a first image (I.sub.1) of the sample, in the fluorescence spectral band, using an image sensor (30); b) illuminating the sample (10) using a second light source (12), in a second spectral band (.sub.2), outside of the fluorescence spectral band, and acquiring a second image (I.sub.2) of the sample, in the second apectral band, using the image sensor;
the image sensor (30) being coupled to an optical system (20) such that: in the fluorescence spectral band (.sub.f), the object focal plane (P.sub.1) of the optical system is coincident with the plane (P.sub.10) of the sample; in the second spectral band, the object focal plane (P.sub.2) of the optical system is offset with respect to the plane (P.sub.10) of the sample, the offset being larger than 20 m.

Provided are on-axis and off-axis digital hologram generating device and method.

The on-axis and off-axis digital hologram generating device includes an object phase generator configured to access a phase file of an object stored in a storage device and generate object phase information from the phase file of the object; a digital object light generator configured to generate digital object light information based on a light property of object light input by a user and the object phase information generated by the object phase generator; a digital reference light generator configured to generate digital reference light information based on a light property of reference light input by the user; and a digital hologram generator configured to generate a digital hologram based on hologram property information input by the user, the digital object light information generated by the digital object light generator, and the digital reference light information generated by the digital reference light generator.

In the present invention, by providing an apparatus for generating a hologram based on human visual system modeling, including a lens configured to focus light emitted from a three-dimensional (3D) object, a sensor configured to detect the light, an object information obtaining unit configured to obtain object information of the 3D object based on information of the lens and a confusion circle size threshold value corresponding to information of the sensor, and a hologram image generating unit configured to generate a hologram image for the 3D object based on the object information, it is possible to provide a method of generating a hologram based on a human visual system capable of generating image information of a three-dimensional object faster and capable of generating a higher-quality hologram image.

A method for obtaining an image of a sample includes illuminating the sample using a light source; acquiring, using an image sensor, a first image of the sample, the image being formed in the detection plane, the first image being representative of an exposure light wave propagating, from the sample, to the image sensor, along a first optical path; modifying an optical refractive index, between the image sensor and the sample; acquiring a second image of the sample, the image being representative of the exposure light wave along a second optical path; and implementing an iterative algorithm that combines the first and second images so as to obtain an image of the sample.

A digital holographic apparatus includes a first hologram generating unit that generates a first hologram by causing first object light in a first observation direction to interfere with first reference light, the first object light being generated by irradiating an observation object with light having a first wavelength, the first reference light being derived from the light having the first wavelength; a second hologram generating unit that generates a second hologram by causing second object light in a second observation direction that differs from the first observation direction to interfere with second reference light, the second object light being generated by irradiating the observation object with light having a second wavelength, the second reference light being derived from the light having the second wavelength; a first image capturing unit that captures the first hologram; and a second image capturing unit that captures the second hologram.

Disclosed is a method of measuring red blood cell membrane fluctuations based on dynamic cell parameters using a digital holographic microscope; the method including a step of modeling the three-dimensional images of red blood cells to be measured, and a step of measuring red blood cell membrane fluctuations based on the three-dimensional images. According to this method, since the three-dimensional images of red blood cells to be measured are modeled and red blood cell membrane fluctuations are measured based on the three-dimensional images, red blood cell membrane fluctuations can be measured more easily.

Techniques to improve image quality in holography utilizing lenses made from materials with non-quantized anisotropic electromagnetic properties, such as birefringent materials, to advantageously split an incoming beam of light into two coincident beams with different focal lengths that interfere with one another and thus create holograms free of electro-optical or pixelated devices are disclosed. Corresponding systems, methods and apparatuses are described.

A device and a method for observing an object by imaging, or by lensless imaging. The object is retained by a holder defining an object plane inserted between a light source and an image sensor, with no enlargement optics being placed between the object and the image sensor. An optical system is arranged between the light source and the holder and is configured to form a convergent incident wave from a light wave emitted by the light source, and for forming a secondary light source, conjugated with the light source, positioned in a half-space defined by the object plane and including the image sensor, such that the secondary source is closer to the image sensor than to the holder. This results in an image with a transversal enlargement factor having an absolute value of less than 1.

A time delay error occurring in the case of acquiring two holograms (object hologram and reference hologram) necessary for reconstruction in the related art or in the case of acquiring four physical holograms having different phase shift degrees may be removed. DC noise (including background noise) may be completely removed by using a software-implemented phase shifting method.

An apparatus and method to produce a hologram of a cross-section of an object includes an electromagnetic radiation assembly configured to receive a received electromagnetic radiation, such as light, from the object. The electromagnetic radiation assembly is further configured to diffract the received electromagnetic radiation and transmit a diffracted electromagnetic radiation. An image capture assembly is configured to capture an image of the diffracted electromagnetic radiation and produce the hologram of the cross-section of the object from the captured image. The hologram of the cross-section includes information regarding a single cross-section of the object.