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The authors describe three-dimensional (3D) motion pictures of dynamic micro objects obtained by parallel phase-shifting digital holographic microscope. The microscope consisted of a Mach-Zehnder interferometer, an inverted magnification optical system, a continuous wave laser, and a polarization imaging camera. An alum crystal sinking in aqueous solution of alum was set for a dynamic micro object...
The wave propagation method (WPM) is a method that can accurately simulate inhomogeneous media at high numerical apertures in the micro-optical size range. Recently, the large computing time for 3D-problems could be reduced significantly, thus enabling rapid simulation for micro optical systems.
In this paper we present some results summarizing our previous work during the last few years in the analysis of Synthetic Aperture Integral Imaging (SAII) performance for human gesture recognition, with a particular emphasis in its accuracy in the presence of occlusions, also when comparing it with sensors and strategies that are commonly used for these tasks, like the RGB-D sensors. Experiments...
A Mirau interferometric objective can be used for common-path and vibration-immune digital holographic microscopy (DHM). However, high-magnification Mirau objectives are expensive and suffer from low working distances, and the commonly used low-magnification Mirau objectives do not have high lateral resolutions. In this paper, we report two different approaches toward enhancing the resolution in Mirau...
In this paper we review the 2D/3D mode switching technologies and suggest a new design for the 2D/3D switchable backlight unit (BLU) with the prism-shaped light extracting pattern structured on the light guide plate (LGP).
Roles and optical responses of microlenses in information optics applications will be discussed. Microlenses can be found from semiconductor fabrication tools to tiny imaging apparatuses equipped in smart electronic devices, therefore, their functionalities and sizes are manifold. We discuss the scaling behavior of micro-optical elements and optical responses in different characteristic sizes. We...
Two recently developed methods that allow visualizing the interaction of THz radiation with arbitrary structures, namely polaritonics and near-field imaging, are reviewed and compared. THz polaritonics, which relies on complex amplified laser systems, allows single-shot image acquisition in a plane perpendicular to the structures. THz near-field imaging, on the other hand, requires only femtosecond...
Fluorescence imaging is one of the important tools for biological field. For three-dimensional (3D) visualization of the fluorescence, we present two approaches. One is the common-path off-axis incoherent digital holography using dual gratings on dual Fresnel lenses. The other method is the image recovery of a defocused 2D fluorescence image by using the defocused distance obtained from the 3D phase...
The rigorous coupled-wave analysis (RCWA) is applied to the simulation of 4π-microscopy. To this end, we combine the concept of structured illumination with coherent two-sided light incidence. It is demonstrated how the latter is integrated into the RCWA framework. With these techniques we simulate two coherent counter-propagating converging beams incident upon a sample as in 4π-microscopy.
We describe several techniques for phase-shifting digital holography based on single-pixel detection and microstructured illumination. In particular, we present a high-speed holographic system based on a Mach-Zehnder interferometer that uses a digital micromirror device (DMD) to sample the object with a sequence of phase patterns. The DMD is also used for phase shifting and for wavefront correction...
Compressive sensing may be particularly beneficial for multidimensional imaging. In this paper we overview techniques developed for 3D and 4D compressive imaging. We briefly discuss implementation issues and possible solutions.
Linear polarizers are present in all kind of optical systems. These devices behave as vector projectors in the polarization direction assuming quasi-transverse beams in the paraxial domain. Nevertheless, the performance of polarizers used in combination with focused beams requires a more in-depth analysis. Understanding this behavior is essential in microscopy applications because of the non-negligible...
Coherent singular beams, in particular optical vortices, are attractive for different applications: free-space optical communication, imaging, particle manipulation, etc. However, their deformation during propagation through random media and speckle noise forced to look to their partially coherent analogues. The singularities of partially coherent beams associated with zero points of the cross-correlation...
New morphological descriptors of complex porous networks are introduced and validated in this paper. These descriptors are based on the concept of “reachable volume fraction” here applied on multi-scale Boolean schemes; this fraction is computable for percolating spheres using step by step erosions of the porous network, providing information about the percolation strength of spherical particles with...
Quantum Key Distribution (QKD) provides a secure way of generating shared cryptographic keys between a sender (Alice) and a receiver (Bob). The original BB84 protocol uses a two-dimensional polarization basis, limiting the information content of a single photon to 1 bit. Using the transverse position of single photons as one basis and the Fourier space as a second basis, one can construct a pair of...
Film-based cameras were replaced with digital cameras in a very short period. Saving film costs for each shot is not only of advantage of this transition. The more important advantage by this digitization is that forming optically a completed image on detector is not necessary and acquired data are processable by a computer. We can think that, with optional optical system-lens array-, acquired data...
In recent years, the optical storage and optical information processing technologies based on holographic and photonic techniques are suffering a huge improvement. On the other hand, Spatial Light Modulators (SLMs) based on LCoS microdisplays (PA-LCoS) open new possibilities to modulate the wavefront of a light beam. PA-LCoS are high resolution reflective devices which make possible the generation...
Optical dot gain, a non-deterministic phenomenon to be taken into account when modeling halftone print reproduction, is revisited under information theory. Its impact is quantified at different scales in an attempt to better understand the dedicated “n-value”.
Many imaging applications rely on sample illumination with known 3-D light distributions. As these 3-D light distributions must satisfy the wave equation, many variables such as the geometry and reflectance of the sample and its environment may cause changes. While in most applications this change is neglected, for many scanning applications where the scanning beam should preserve its characteristics...
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