A dark field digital holographic microscope is disclosed which is configured to determine a characteristic of interest of a structure. The dark field digital holographic microscope comprises an illumination device configured to provide at least: a first beam pair comprising a first illumination beam of radiation (1010) and a first reference beam of radiation (1030) and a second beam pair comprising a second illumination beam of radiation (1020) and a second reference beam of radiation (1040); and one or more optical elements (1070) operable to capture a first scattered radiation and to capture a second scattered radiation scattered by the structure resultant from the first and second illumination beams respectively. The beams of the first beam pair are mutually coherent and the beams of the second beam pair are mutually coherent. The illumination device is configured to impose incoherence (ADI) between the first beam pair and second beam pair.

According to an embodiment, a holographic microscope comprises a light source emitting light to an object, a beam splitter reflecting the light emitted from the light source to the object and transmitting object light reflected from the object, a holographic image sensor sensing information, including a holographic image, by receiving the object light and allowing the object light to coherently interfere with reference light, and an image processor obtaining three-dimensional (3D) information about the object based on the information sensed by the holographic image sensor. The holographic image sensor includes a lens focusing the object light to the holographic image sensor, a filter transmitting a predetermined wavelength band of light of the focused object light, a light receiving unit receiving interference light to sense a holographic image, and a reference light source directly emitting the reference light having the predetermined wavelength band to the light receiving unit.

The present invention provides a surface shape measuring device and a surface shape measuring method which do not require a physical reference plane and can improve measurement accuracy without using a mechanical adjustment mechanism. The illumination light condensing point P.sub.Q and the reference light condensing point P.sub.L are arranged as mirror images of each other with respect to the virtual plane VP, and each data of the object light O, being a reflected light of the spherical wave illumination light Q, and the inline spherical wave reference light L is recorded on each hologram. On the virtual plane VP, the reconstructed object light hologram h.sup.V for measurement is generated, and the spherical wave optical hologram s.sup.V representing a spherical wave light emitted from the reference light condensing point P.sub.L is analytically generated. The height distribution of the surface to be measured of the object 4 is obtained from the phase distribution obtained by dividing the reconstructed object light hologram h.sup.V by the spherical wave light hologram s.sup.V. High-accuracy surface shape measurement without requiring a reference plane such as a glass substrate is realized by comparing the phase data of the reflected light acquired from the surface to be measured and the phase distribution on the plane cut surface of the spherical wave obtained analytically.

The illumination light condensing point P.sub.Q and the reference light condensing point P.sub.L are arranged as mirror images of each other with respect to the virtual plane VP, and each data of the object light O, being a reflected light of the spherical wave illumination light Q, and the inline spherical wave reference light L is recorded on each hologram. On the virtual plane VP, the reconstructed object light hologram h.sup.V for measurement is generated, and the spherical wave optical hologram s.sup.V representing a spherical wave light emitted from the reference light condensing point P.sub.L is analytically generated. The height distribution of the surface to be measured of the object 4 is obtained from the phase distribution obtained by dividing the reconstructed object light hologram h.sup.V by the spherical wave light hologram s.sup.V.

A holographic imaging device and method realizes both a transmission type and a reflection type, and also realizes a long working distance wide field of view or ultra-high resolution. Object light emitted from an object, sequentially illuminated with parallel illumination light whose incident direction is changed, is recorded on a plurality of object light holograms for each incident direction using off-axis spherical wave reference light. The reference light is recorded on a reference light hologram using in-line spherical wave reference light being in-line with the object light. An object light wave hologram and its spatial frequency spectrum at the object position are generated for each incident direction using each hologram. A synthetic spectrum which occupies a wider frequency space is generated by matching each spectrum in the overlapping area, and a synthetic object light wave hologram with increased numerical aperture is obtained thereby.

A system for analyzing a transparent particle including: an analysis pathway, including a first light source emitting an analysis light beam, and a first optical system focusing the analysis light beam in a focusing plane; and a position control pathway including a second light source, an image sensor, and a second optical system at least partially merged with the first optical system. The image sensor is offset relative to the image of the focusing plane by the second optical system. The system makes it possible to control correct positioning of the particle, even though it is transparent, and without disturbing the analysis pathway.

The invention relates to a system (1) for observing objects, including: a light source (3), a holder (12) able to receive a translucent or opaque substrate, a detector (7) able to collect the backscattered light from the interaction between the light emitted by light source (3) and the objects, a polarization splitter (9), and a quarter-wave plate (10), the splitter (9) and the quarter-wave plate (10) being arranged so that the splitter (9) directs the light emitted by the light source (3) toward the solid substrate and directs the backscattered light from the interaction between the light emitted by the light source (3) and the objects toward the detector (7).

Embodiments of the present disclosure provide an imaging device for holographic imaging of a sample, the imaging device comprising a light source generating a light beam, a beam splitter splitting the light beam into an object beam along an object beam path and a reference beam along a reference beam path, and a detector. The imaging device defines a sample position. The object beam is propagated through the sample position, and the detector is arranged to prevent non-scattered object light, passing through the sample position without being scattered by the sample, from being incident onto the detector. The reference beam is propagated through the sample position, and the detector is arranged so that non-scattered reference light, passing through the sample position without being scattered by the sample, is incident onto the detector. The detector detects an interference pattern formed by scattered object light and the non-scattered reference light.

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.

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.