Simultaneous amplitude-contrast and quantitative phase-contrast microscopy by numerical reconstruction of Fresnel off-axis holograms (original) (raw)
Related papers
Local amplitude and phase retrieval method for digital holography applied to microscopy
Novel Optical Instrumentation for Biomedical Applications, 2003
We present a numerical two-step reconstruction procedure for digital off-axis Fresnel holograms. First, we retrieve the amplitude and phase of the object wave in the CCD plane. For each point we solve a weighted linear set of equations in the least-squares sense. The algorithm has O(N) complexity and gives great flexibility. Second, we numerically propagate the obtained wave to achieve proper focus. We apply the method to microscopy and demonstrate its suitability for the real time imaging of biological samples.
Digital holography for quantitative phase-contrast imaging
1999
We present a new application of digital holography for phase-contrast imaging and optical metrology. This holographic imaging technique uses a CCD camera for recording of a digital Fresnel off-axis hologram and a numerical method for hologram reconstruction. The method simultaneously provides an amplitude-contrast image and a quantitative phase-contrast image. An application to surface profilometry is presented and shows excellent agreement with contact-stylus probe measurements.
Applied Optics, 2003
An approach is proposed for removing the wave front curvature introduced by the microscope imaging objective in digital holography, which otherwise hinders the phase contrast imaging at reconstruction planes. The unwanted curvature is compensated by evaluating a correcting wave front at the hologram plane with no need for knowledge of the optical parameters, focal length of the imaging lens, or distances in the setup. Most importantly it is shown that a correction effect can be obtained at all reconstruction planes. Three different methods have been applied to evaluate the correction wave front and the methods are discussed in detail. The proposed approach is demonstrated by applying digital holography as a method of coherent microscopy for imaging amplitude and phase contrast of microstructures.
Optically-undistorted digital holographic microscopy for quantitative phase-contrast imaging
2011 10th Euro-American Workshop on Information Optics, 2011
We propose a telecentric architecture for circumventing, by a pure-optical method, the residual phase distortion inherent to standard configuration of digital holographic microscopy (DHM). With this proposal there is no need for computer compensation of the parabolic phase during the phase map recovering procedure. Futhermore, in off-axis configuration, the spatial frequency useful domain is enlarged.
Off-axis digital holographic camera for quantitative phase microscopy
Biomedical Optics Express, 2014
We propose and experimentally demonstrate a digital holographic camera which can be attached to the camera port of a conventional microscope for obtaining digital holograms in a self-reference configuration, under short coherence illumination and in a single shot. A thick holographic grating filters the beam containing the sample information in two dimensions through diffraction. The filtered beam creates the reference arm of the interferometer. The spatial filtering method, based on the high angular selectivity of the thick grating, reduces the alignment sensitivity to angular displacements compared with pinhole based Fourier filtering. The addition of a thin holographic grating alters the coherence plane tilt introduced by the thick grating so as to create highvisibility interference over the entire field of view. The acquired full-field off-axis holograms are processed to retrieve the amplitude and phase information of the sample. The system produces phase images of cheek cells qualitatively similar to phase images extracted with a standard commercial DHM.
High-resolution quantitative phase-contrast microscopy by digital holography
Optics Express, 2005
Techniques of digital holography are improved in order to obtain highresolution, high-fidelity images of quantitative phase-contrast microscopy. In particular, the angular spectrum method of calculating holographic optical field is seen to have significant advantages including tight control of spurious noise components. Holographic phase images are obtained with 0.5 μm diffraction-limited lateral resolution and largely immune from the coherent noise common in other holographic techniques. The phase profile is accurate to about 30 nm of optical thickness. Images of SKOV-3 ovarian cancer cells display intracellular and intranuclear organelles with clarity and quantitative accuracy.
Methods of Fourier optics in digital holographic microscopy
Optics Communications, 2008
In this paper, processing methods of Fourier optics implemented in a digital holographic microscopy system are presented. The proposed methodology is based on the possibility of the digital holography in carrying out the whole reconstruction of the recorded wave front and consequently, the determination of the phase and intensity distribution in any arbitrary plane located between the object and the recording plane. In this way, in digital holographic microscopy the field produced by the objective lens can be reconstructed along its propagation, allowing the reconstruction of the back focal plane of the lens, so that the complex amplitudes of the Fraunhofer diffraction, or equivalently the Fourier transform, of the light distribution across the object can be known. The manipulation of Fourier transform plane makes possible the design of digital methods of optical processing and image analysis. The proposed method has a great practical utility and represents a powerful tool in image analysis and data processing. The theoretical aspects of the method are presented, and its validity has been demonstrated using computer generated holograms and images simulations of microscopic objects.
Three-dimensional microscopy with phase-shifting digital holography
Optics letters, 1998
We applied phase-shifting digital holography to microscopy by deriving the complex amplitude of light scattered from microscopic three-dimensional objects through a microscope objective by video camera recording, phaseshifting analysis, and computer reconstruction. This method requires no mechanical movement and provides a f lexible display and quantitative evaluation of the reconstructed images. A theory of image formation and experimental verification with specimens are described.
Physical phase compensation in digital holographic microscopy
2009
In digital holographic microscopy (DHM), using microscope objective for sample imaging may introduce additional spherical phase curvature. It can be physically compensated by introducing a same phase curvature in the reference beam. A theoretical analysis of the wavefront interefence between the reference beam and object beam is provided to indicate the physical phase compensation. The spatial frequency spectra of the hologram are involved for the judgement of the physical phase compensation status. Different DHM setups are presented in order to fulfill the physical compensation of the introduced spherical phase. In the DHM setups based on the Michelson interferometric configuration, an adjustable lens is used to perform the quasi physical phase compensation during the hologram recording. In the common-path DHM setups, digital off-axis holograms are recorded by using a single cube beam splitter in a non-conventional configuration so as to both split and combine a diverging spherical wavefront emerging from a microscope objective. A simple plane numerical reference wavefront is used for the reconstruction and the correct quantitative phase map of the test object is obtained after phase unwrapping. Its simplicity of the presented setups make it easy to be well aligned and with lower cost.