Digital Holo-Microscopy of Reflecting Surface Using In-Line Laser Interferometry
01 Jan 2020-pp 123-127
TL;DR: In this article, a simple and compact configuration for Digital Holography of microscopic reflecting structures is presented, which employs a Wire Grid Polarizer (WGP) to obtain two orthogonally polarized light beams serving as reference and object information.
Abstract: A simple and compact configuration for Digital Holography of microscopic reflecting structures is presented. The proposed technique employs a Wire grid polarizer (WGP) to obtain two orthogonally polarized light beams serving as reference and object information. The salient features of the proposed technique include in-line common path configuration, which provides less phase noise and less distortion from ambient vibrations. As demonstrated, the proposed design has the potential to implement Polarization Phase Shifting.
Citations
More filters
[...]
TL;DR: In this article , a wire-grid polarizer (WGP) is placed on the laser beam illuminating the sample, where the WGP serves the dual purpose of a beam splitter and a polarization separator where the reference and sample beams reflected and transmitted from it respectively are orthogonally polarized.
Abstract: This work describes a full-field and near-common-path in-line laser interferometer and interferometric microscope utilizing a wire-grid polarizer (WGP) placed normally on the laser beam illuminating the sample. The WGP serves the dual purpose of a beam splitter and a polarization separator where the reference and sample beams reflected and transmitted from it respectively are orthogonally polarized so that, unlike other conventional interferometers, polarization phase shifting is inherent in its architecture. This arrangement presents experimental results showing quantitative phase analysis of transparent and reflecting phase samples.
1 citations
References
More filters
[...]
TL;DR: A new method is proposed in which the distribution of complex amplitude at a plane is measured by phase-shifting interferometry and then Fresnel transformed by a digital computer, which can reconstruct an arbitrary cross section of a three-dimensional object with higher image quality and a wider viewing angle than from conventional digital holography using an off-axis configuration.
Abstract: A new method for three-dimensional image formation is proposed in which the distribution of complex amplitude at a plane is measured by phase-shifting interferometry and then Fresnel transformed by a digital computer. The method can reconstruct an arbitrary cross section of a three-dimensional object with higher image quality and a wider viewing angle than from conventional digital holography using an off-axis configuration. Basic principles and experimental verification are described.
1,712 citations
[...]
TL;DR: Off-axis holograms recorded with a magnified image of microscopic objects are numerically reconstructed in amplitude and phase by calculation of scalar diffraction in the Fresnel approximation to show that the transverse resolution is equal to the diffraction limit of the imaging system.
Abstract: We present a digital method for holographic microscopy involving a CCD camera as a recording device. Off-axis holograms recorded with a magnified image of microscopic objects are numerically reconstructed in amplitude and phase by calculation of scalar diffraction in the Fresnel approximation. For phase-contrast imaging the reconstruction method involves the computation of a digital replica of the reference wave. A digital method for the correction of the phase aberrations is presented. We present a detailed description of the reconstruction procedure and show that the transverse resolution is equal to the diffraction limit of the imaging system.
1,115 citations
[...]
TL;DR: The principles and major applications of digital recording and numerical reconstruction of holograms (digital holography) are described, which are applied to measure shape and surface deformation of opaque bodies and refractive index fields within transparent media.
Abstract: This article describes the principles and major applications of digital recording and numerical reconstruction of holograms (digital holography). Digital holography became feasible since charged coupled devices (CCDs) with suitable numbers and sizes of pixels and computers with sufficient speed became available. The Fresnel or Fourier holograms are recorded directly by the CCD and stored digitally. No film material involving wet-chemical or other processing is necessary. The reconstruction of the wavefield, which is done optically by illumination of a hologram, is performed by numerical methods. The numerical reconstruction process is based on the Fresnel–Kirchhoff integral, which describes the diffraction of the reconstructing wave at the micro-structure of the hologram. In the numerical reconstruction process not only the intensity, but also the phase distribution of the stored wavefield can be computed from the digital hologram. This offers new possibilities for a variety of applications. Digital holography is applied to measure shape and surface deformation of opaque bodies and refractive index fields within transparent media. Further applications are imaging and microscopy, where it is advantageous to refocus the area under investigation by numerical methods.
1,104 citations
[...]
TL;DR: The novelty of the proposed configuration is its simplicity, minimal number of optical elements, insensitivity to vibration, and its inherent capability to compensate for the phase curvature that results from the illuminating wavefront in the case of microscopic samples.
Abstract: A new optical configuration for digital holographic microscopy is presented. Digital off-axis holograms are recorded by use of a single cube beam splitter in a nonconventional configuration to both split and combine a diverging spherical wavefront as it emerges from a single point source. Both the amplitude and the phase can then be reconstructed, yielding intensity and phase images with improved resolution. The novelty of the proposed configuration is its simplicity, minimal number of optical elements, insensitivity to vibration, and its inherent capability to compensate for the phase curvature that results from the illuminating wavefront in the case of microscopic samples.
38 citations
Related Papers (5)
[...]
[...]
[...]