Search results for "Sectioning"
showing 10 items of 43 documents
Axial gain resolution in optical sectioning fluorescence microscopy by shaded-ring filters.
2009
We present a new family of pupil masks to control the axial component of the intensity distribution in the focal region of tightly focused light fields. The filters, which consist of a circular clear pupil with a single shaded ring, allow to control the width of the central lobe of the axial spot together with the residual sidelobes energy. The filters can be applied to improve the optical sectioning capacity of different scanning microscopes.
Removing striping artifacts in light-sheet fluorescence microscopy: a review
2022
Abstract In recent years, light-sheet fluorescence microscopy (LSFM) has found a broad application for imaging of diverse biological samples, ranging from sub-cellular structures to whole animals, both in-vivo and ex-vivo, owing to its many advantages relative to point-scanning methods. By providing the selective illumination of sample single planes, LSFM achieves an intrinsic optical sectioning and direct 2D image acquisition, with low out-of-focus fluorescence background, sample photo-damage and photo-bleaching. On the other hand, such an illumination scheme is prone to light absorption or scattering effects, which lead to uneven illumination and striping artifacts in the images, oriented…
Subtractive imaging in confocal scanning microscopy using a CCD camera as a detector
2012
[EN] We report a scheme for the detector system of confocal microscopes in which the pinhole and a large-area detector are substituted by a CCD camera. The numerical integration of the intensities acquired by the active pixels emulates the signal passing through the pinhole. We demonstrate the imaging capability and the optical sectioning of the system. Subtractive-imaging confocal microscopy can be implemented in a simple manner, providing superresolution and improving optical sectioning. (C) 2012 Optical Society of America
Thermal camera calibration with cooled down chessboard
2019
International audience; Calibration of a camera have various applications in computer vision. This process is particularly challenging with a thermal camera instead of a standard color one. A calibration target with two layers of different thermal emissivity is commonly used but reflects appear and degrade the corner extraction of the chessboard. While traditional and commonly used methods heat the target chessboard, we cool it down that inverts the distribution of emission of the two layers. The reflects on the reflective layer enhance the contrast instead of decreasing it. Experiments on various configurations and orientations demonstrate the superiority of the proposed method.
Optical transfer function engineering for a tunable 3D structured illumination microscope
2019
Two important features of three-dimensional structured illumination microscopy (3D-SIM) are its optical sectioning (OS) and super-resolution (SR) capabilities. Previous works on 3D-SIM systems show that these features are coupled. We demonstrate that a 3D-SIM system using a Fresnel biprism illuminated by multiple linear incoherent sources provides a structured illumination pattern whose lateral and axial modulation frequencies can be tuned separately. Therefore, the compact support of the synthetic optical transfer function (OTF) can be engineered to achieve the highest OS and SR capabilities for a particular imaging application. Theoretical performance of our engineered system based on the…
Confocal scanning microscope using a CCD camera as a pinhole-detector system
2011
We report a scheme for a detector system of confocal microscopes. In our scheme the pinhole and the large area detector are subtituted by a CCD camera. The numerical integration of the intensities acquired by the active pixels emulates the signal acquired by the detector. To demonstrate the utility of the system we efficiently performed an experiment of substractive-image confocal microscopy
Improvement of two-dimensional structured illumination microscopy with an incoherent illumination pattern of tunable frequency.
2018
In two-dimensional structured illumination microscopy (2D-SIM), high-resolution images with optimal optical sectioning (OS) cannot be obtained simultaneously. This tradeoff can be overcome by using a tunable-frequency 2D-SIM system and a proper reconstruction method. The goal of this work is twofold. First, we present a computational approach to reconstruct optical-sectioned images with super-resolution enhancement (OS-SR) by using a tunable SIM system. Second, we propose an incoherent tunable-frequency 2D-SIM system based on a Fresnel biprism implementation. Integration of the proposed computational method with this tunable structured illumination (SI) system results in a new 2D-SIM system…
Optimal design of incoherent tunable-frequency structured illumination microscope scheme
2018
Structured illumination microscopy (SIM) improves resolution and optical sectioning capability compared to conventional widefield techniques. The main idea of this method is the illumination of the sample with a structured pattern of fixed spatial modulation frequency. Previously, a Fresnel biprism has been implemented in a structured illumination (SI) device providing tunable-frequency sinusoidal patterns. However, the use of this SI system introduces a tradeoff between the visibility and field of view of the illumination fringes. In this contribution, we analyze theoretically this tradeoff and propose the optimal design for the Fresnel biprism-based SIM system.
Diffractive optics for high-resolution low-coherence digital holography
2010
We study the properties of the recording of off-axis holograms when a 10 fs pulsed laser is used as illumination source. A proper optical design involving one diffractive lens outside a Michelson interferometer enables the recording of full-field off-axis holograms with high resolution and optical sectioning. We demonstrate our approach with some experimental results that show optical sectioning with a maximum resolution of 3.5 µm. We note that the axial resolution of the technique is reduced up to 9 µm when the object beam travels through a few millimeters of glass due to the pulse broadening along dispersive media.
Diffractive pulse-front tilt for low-coherence digital holography
2010
We use a diffractive lens to generate the proper pulse-front-tilt to record full-field off-axis holograms with a 10fs laser source. We experimentally demonstrate optical sectioning of three-dimensional samples with a resolution of about 5 microns.