Image plane | EPFL Graph Search

In 3D computer graphics, the image plane is that plane in the world which is identified with the plane of the display monitor used to view the image that is being rendered. It is also referred to as screen space. If one makes the analogy of taking a photograph to rendering a 3D image, the surface of the film is the image plane. In this case, the viewing transformation is a projection that maps the world onto the image plane. A rectangular region of this plane, called the viewing window or viewport, maps to the monitor. This establishes the mapping between pixels on the monitor and points (or rather, rays) in the 3D world. The plane is not usually an actual geometric object in a 3D scene, but instead is usually a collection of target coordinates or dimensions that are used during the rasterization process so the final output can be displayed as intended on the physical screen. In optics, the image plane is the plane that contains the object's projected image, and lies beyond the back

Broadband Digital Holographic Camera for Microscopy

Zahra Monemhaghdoust

In this thesis, we explore a combination of analog and digital holographic techniques to demonstrate high speed quantitative phase imaging (QPI) using low coherence (broad bandwidth) light sources. Off-axis digital holographic microscopy is inherently a coherent method of phase quantification and thus suffers from coherent noise. However, only one measurement is required to retrieve field information which gives an advantage in term of image acquisition speed. While incoherent methods of phase quantification remove the problem of coherent noise, they require acquiring several measurements which is sometimes not acceptable in the study of dynamical systems. Therefore, this thesis is an attempt to extend off-axis digital holographic microscopy from the coherent to the incoherent regime to maintain the benefit of high speed measurement capability of off-axis holography while reducing the coherent noise. First, we demonstrate that by using a suitable combination of holographic gratings, off-axis digital holographic microscopy can work with spectrally broadband illumination sources. Holographic gratings introduce a tilt in the coherence plane of one of the reference or object arms of an off-axis digital holographic microscope to expand the interference area to the whole field of view of the camera. Although QPI provides useful information in addition to state-of-the-art intensity-based microscopic imaging, its use has not permeated yet far beyond research laboratories. One potential reason is the need for a stand-alone dedicated microscope system, which is expensive and not back-compatible to the existing wide-field microscopes. In this Regard, the second part of this thesis explores an add-on camera module which can be attached to the camera port of any standard intensity microscope. The techniques developed to extend the off-axis DHM in the first part of the thesis will be used to demonstrate a proof-of-concept camera module which operates with broadband light sources. Overall, through the combination of analog and digital holography, the goal of this work is to extend full-field off-axis holography to incoherent regime to benefit from real-time speckle-free measurements, optical sectioning and realization of a digital holographic camera which can be placed in the image plane of a standard optical microscope.

EPFL2015

Optically sectioned image generating method for microscopy imaging apparatus involves combining measured characteristics of signals from respective positions of conjugate image plane to generate optically sectioned image of specimen

Stéphane Bourquin, Theo Lasser, Jelena Mitic, Karsten Plamann, François Richard Vuille

A method and a microscopy imaging apparatus for generating an optically sectioned image of a specimen are provided. The method comprises the steps of:illuminating the specimen with a modulating, spatially periodic illumination pattern; imaging said specimen on a conjugate image plane; acquiring a plurality of signals at respective positions on said image plane, each signal corresponding to the incident light intensity at that position and having an oscillatory component caused by the modulation of the illumination pattern; and measuring a characteristic of the oscillatory component of each of the signals, whereby the measured characteristics when combined in their relative positions generate an optically sectioned image of the specimen.

2003

Holographic imaging of electromagnetic fields via electron-light quantum interference

Gabriele Berruto, Fabrizio Carbone, Tatiana Latychevskaia, Tom Theodorus Antonius Lummen, Ivan Madan, Enrico Pomarico, Giovanni Maria Vanacore

Holography relies on the interference between a known reference and a signal of interest to reconstruct both the amplitude and the phase of that signal. With electrons, the extension of holography to the ultrafast time domain remains a challenge, although it would yield the highest possible combined spatiotemporal resolution. Here, we show that holograms of local electromagnetic fields can be obtained with combined attosecond/nanometer resolution in an ultrafast transmission electron microscope (UEM). Unlike conventional holography, where signal and reference are spatially separated and then recombined to interfere, our method relies on electromagnetic fields to split an electron wave function in a quantum coherent superposition of different energy states. In the image plane, spatial modulation of the electron energy distribution reflects the phase relation between reference and signal fields. Beyond imaging applications, this approach allows implementing quantum measurements in parallel, providing an efficient and versatile tool for electron quantum optics.

American Association for the Advancement of Science (AAAS)2019

Broadband Digital Holographic Camera for Microscopy

Zahra Monemhaghdoust

EPFL2015