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.

The present disclosure discloses a hologram recording device and a hologram recording method. The hologram recording device comprises an object imaging unit comprising a cavity for accommodating an object whose interior wall is a reflective surface, and a light modulating unit configured to produce incident light and reference light interfering with the incident light and to direct the incident light to the object imaging unit. The cavity is provided with an imaging aperture for imaging of the object and at least one light incidence aperture for allowing the incident light to enter the cavity and irradiate on the object, such that an image of the object is formed at a location corresponding to the imaging aperture outside the cavity, and image light produced upon the imaging of the object interferes with the reference light at the location for recording of an image surface hologram.

The present invention can realize both a transmission type and a reflection type, and provides a holographic microscope which can exceed the resolution of the conventional optical microscope, a hologram data acquisition method for a high-resolution image, and a high-resolution hologram image reconstruction method. In-line spherical wave reference light (L) is recorded in a hologram (I.sub.LR) using spherical wave reference light (R), and an object light (O.sup.j) and an illumination light (Q.sup.j) are recorded in a hologram (I.sup.j.sub.OQR) using a spherical wave reference light (R) by illuminating the object with an illumination light (Q.sup.j, j=1, . . . , N) which is changed its incident direction. From those holograms, a hologram (J.sup.j.sub.OQL), from which the component of the reference light (R) is removed, is generated, and from the hologram, a light wave (h.sup.j) is generated. A light wave (c.sup.j) of the illumination light (Q.sup.j) is separated from the light wave (h.sup.j), and using its phase component (.sup.j=c.sup.j/|c.sup.j|), a phase adjustment reconstruction light wave is derived and added up as (H.sub.P=h.sup.j/.sup.j), and an object image (S.sub.P=|H.sub.P|.sup.2) is reconstructed.

Methods, systems, and devices for particle characterization by optical phase modulation and detection of aerosol backscattering. In some aspects, a compact and cost effective particle detector device to measure the aerosol density and its size distribution by backscattered focusing using projected optical modified field distribution imaging into the aerosol medium (air). The disclosed device can be used in a variety of scientific and industrial applications, e.g., such as a particle sensor for automobiles able to detect harmful pollution which may then be filtered from the car cabin, or warnings provided to the driver. The device can also capture and store data, enabling detailed pollution maps of various roadways in real-time.

The present invention relates to an inline scanning holography system for a phosphor and a transmitter. According to the present invention, the inline scanning holography system includes a polarization sensitive lens that receives a linearly polarized beam and generates a first spherical wave of right-handed circular polarized light having a negative focal length and a second spherical wave of left-handed circular polarized light having a positive focal length, a polarizer that passes only a beam component in a predetermined polarization direction therethrough among components of the generated first and second spherical waves, a scanning unit for scanning a phosphor by using an interference beam generated between the first and second spherical waves passing through the polarizer, and a first photodetector that detects a fluorescent beam diverged from the phosphor. According to the present invention, a high-efficiency and high-quality optical scanning holography for a phosphor or a transmitter may be implemented.

The imaging apparatus includes an optical system dividing light into object and reference beams and causing the object beam and the reference beam to interfere with each other to form interference fringes on an image sensor. A processor performs multiple imaging processes for the interference fringes with different incident angles of the object beam to an object, a first process to acquire a transmitted wavefront for each incident angle and a second process to calculate a three-dimensional refractive index distribution from the transmitted wavefronts. The apparatus includes a modulator changing a phase distribution of light in any one of an optical path from a light source to a dividing element, a reference beam path and an optical path from a combining element to the image sensor and causes the modulator to change the phase distribution in at least one of the multiple imaging processes.

Examples include imaging one or more objects contained inside a droplet. A method includes generating at least one hologram of the one or more objects contained in the droplet by using in-line lens-free imaging. The at least one hologram includes at least one artifact that is caused by the droplet and that affects the at least one characteristic of the one or more objects contained in the droplet. The method includes at least partially removing the at least one artifact or the cause of the at least one artifact. The method further includes generating an image, after or during removing the at least one artifact or the cause of the at least one artifact. The image includes the one or more objects. The method also comprises recognizing the at least one characteristic of the one or more objects based on the image.

A digital holographic microscope that includes a light source and a photonic integrated circuit. The photonic integrated circuit can include a branching waveguide optically coupled to the light source, and a multi-angle illumination device optically coupled to the branching waveguide. In various examples, the multi-angle illumination device includes an optical phased array that includes a plurality of light emitters. In various examples, the multi-angle illumination device includes a grating coupler.

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.

The present disclosure discloses a hologram recording device and a hologram recording method. The hologram recording device comprises an object imaging unit comprising a cavity for accommodating an object whose interior wall is a reflective surface, and a light modulating unit configured to produce incident light and reference light interfering with the incident light and to direct the incident light to the object imaging unit. The cavity is provided with an imaging aperture for imaging of the object and at least one light incidence aperture for allowing the incident light to enter the cavity and irradiate on the object, such that an image of the object is formed at a location corresponding to the imaging aperture outside the cavity, and image light produced upon the imaging of the object interferes with the reference light at the location for recording of an image surface hologram.