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We designed and fabricated a functionally integrated optical waveguide illuminator specially for common-path digital holographic microscopy through random media. The waveguide illuminator creates two point sources with desired phase shifts, which are located close to one another so that the common-path condition of the object and reference illumination is satisfied. Thereby, the proposed device permits phase-shift digital holographic microscopy free from bulky optical elements such as a beam splitter, an objective lens, and a piezoelectric transducer for phase shifting. Using the proposed device, microscopic 3D imaging through a highly heterogeneous double-composite random medium was experimentally demonstrated by means of common-path phase-shift digital holography.

We propose a new technique for achromatic 3-D field correlation that makes use of the characteristics of both axial and lateral magnifications of imaging through a common-path Sagnac shearing interferometer. With this technique, we experimentally demonstrate, for the first time to our knowledge, 3-D image reconstruction of coherence holography with generic thermal light. By virtue of the achromatic axial shearing implemented by the difference in axial magnifications in imaging, the technique enables coherence holography to reconstruct a 3-D object with an axial depth beyond the short coherence length of the thermal light.

Unconventional holography called photon correlation holography is proposed and experimentally demonstrated. Using photon correlation, i.e. intensity correlation or fourth order correlation of optical field, a 3-D image of the object recorded in a hologram is reconstructed stochastically with illumination through a random phase screen. Two different schemes for realizing photon correlation holography are examined by numerical simulations, and the experiment was performed for one of the reconstruction schemes suitable for the experimental proof of the principle. The technique of photon correlation holography provides a new insight into how the information is embedded in the spatial as well as temporal correlation of photons in the stochastic pseudo thermal light.

Coherence holography capable of real-time recording and reconstruction is proposed and experimentally demonstrated with a generic Leith-type coherence hologram. The coherence hologram is optically generated in real-time using a Mach-Zehnder interferometer and reconstructed using a Sagnac radial shearing interferometer. With this method one can create an optical field distribution with a desired spatial coherence function, and visualize the coherence function in real-time as the contrast and phase variations in an interference fringe pattern. The reconstructed image of the complex coherence function has been quantified with the Fourier transform method of fringe-pattern analysis.

A new image reconstruction scheme for coherence holography using a modified Sagnac-type radial shearing interferometer with geometric phase shift is proposed, and the first experimental demonstration of generic Leith-type coherence holography, which reconstructs off-axis 3-D objects with depth information, is presented. The reconstructed image, represented by a coherence function, can be visualized with a controllable magnification, which opens up a new possibility for a coherence imaging microscope.

Techniques of unconventional holography, called holographic correloscopy, for imaging a three-dimensional (3-D) object through an opaque diffuser or via a scattering wall are reviewed. This paper is not intended to be a general overview. Instead, it will focus and shed light on less-known techniques termed coherence holography, photon-correlation holography, remote imaging digital holography, and dual-reference holography. This paper will introduce how they perform 3-D imaging through a diffuser or via a scattering wall with a thin but strongly scattering layer. [ABSTRACT FROM PUBLISHER]

Raster scan systems can introduce cubic and quadratic phase distortions in holograms for generating and detecting doughnut beams. The distortions can be corrected by subtracting corresponding terms from the hologram design. The compensation parameters can be determined by fabricating test holograms and applying rotational symmetry analysis to the intensity distribution of the generated beams. The 2- and 3-fold rotational symmetry components are shown to be effective in determining quadratic and cubic corrections respectively, and in the final corrected hologram the total contribution of anisotropic intensity components was reduced to 0.3%. [ABSTRACT FROM AUTHOR]

Abstract: Rather than regarding the phase singularities as obstacles or nuisances in phase unwrapping, we explore new possibilities of making use of the phase singularities in optical metrology. Instead of intensity correlation techniques used in conventional speckle metrology, we propose a new technique of displacement measurement that makes use of the density of phase singularities in the complex analytic signal of the speckle pattern, which is generated by Hilbert filtering. Experimental results and theoretical analysis are presented that demonstrate the validity of the proposed technique. [Copyright &y& Elsevier]