Are you an EPFL student looking for a semester project?
Work with us on data science and visualisation projects, and deploy your project as an app on top of GraphSearch.
Concept
Optical resolution
Summary
Optical resolution describes the ability of an imaging system to resolve detail, in the object that is being imaged.
An imaging system may have many individual components, including one or more lenses, and/or recording and display components. Each of these contributes (given suitable design, and adequate alignment) to the optical resolution of the system; the environment in which the imaging is done often is a further important factor.
Resolution depends on the distance between two distinguishable radiating points. The sections below describe the theoretical estimates of resolution, but the real values may differ. The results below are based on mathematical models of Airy discs, which assumes an adequate level of contrast. In low-contrast systems, the resolution may be much lower than predicted by the theory outlined below. Real optical systems are complex, and practical difficulties often increase the distance between distinguishable point sources.
The resolution of a system is based on the minimum distance at which the points can be distinguished as individuals. Several standards are used to determine, quantitatively, whether or not the points can be distinguished. One of the methods specifies that, on the line between the center of one point and the next, the contrast between the maximum and minimum intensity be at least 26% lower than the maximum. This corresponds to the overlap of one Airy disk on the first dark ring in the other. This standard for separation is also known as the Rayleigh criterion. In symbols, the distance is defined as follows:
where
is the minimum distance between resolvable points, in the same units as is specified
is the wavelength of light, emission wavelength, in the case of fluorescence,
is the index of refraction of the media surrounding the radiating points,
is the half angle of the pencil of light that enters the objective, and
is the numerical aperture
This formula is suitable for confocal microscopy, but is also used in traditional microscopy.
Official source
About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
Related publications (22)
Related people (37)
Related concepts (31)
Diffraction-limited system
In optics, any optical instrument or system a microscope, telescope, or camera has a principal limit to its resolution due to the physics of diffraction. An optical instrument is said to be diffraction-limited if it has reached this limit of resolution performance. Other factors may affect an optical system's performance, such as lens imperfections or aberrations, but these are caused by errors in the manufacture or calculation of a lens, whereas the diffraction limit is the maximum resolution possible for a theoretically perfect, or ideal, optical system.
Point spread function
The point spread function (PSF) describes the response of a focused optical imaging system to a point source or point object. A more general term for the PSF is the system's impulse response; the PSF is the impulse response or impulse response function (IRF) of a focused optical imaging system. The PSF in many contexts can be thought of as the extended blob in an image that represents a single point object, that is considered as a spatial impulse. In functional terms, it is the spatial domain version (i.e.
Super-resolution microscopy
Super-resolution microscopy is a series of techniques in optical microscopy that allow such images to have resolutions higher than those imposed by the diffraction limit, which is due to the diffraction of light. Super-resolution imaging techniques rely on the near-field (photon-tunneling microscopy as well as those that use the Pendry Superlens and near field scanning optical microscopy) or on the far-field.
Related courses (6)
PHYS-631: Fundamentals of superresolution optical microscopy and Scanning Probe Microscopy
The course starts from general discussion of the microscopy spatial resolution problem and different proposals to beat classical criteria in the field. Afterwards, modern scanning probe microscopy met
PHYS-317: Optics I
L'optique est un vieux domaine qui touche à beaucoup de sujets modernes, des techniques expérimentales aux applications courantes. Ce premier cours traite plusieurs aspects de base de l'optique: propa
MSE-352: Introduction to microscopy + Laboratory work
Ce cours d'introduction à la microscopie a pour but de donner un apperçu des différentes techniques d'analyse de la microstructure et de la composition des matériaux, en particulier celles liées aux m
Related lectures (50)
Michelson-Morley Interferometer
Explores the Michelson-Morley interferometer and the detection of minimal mirror displacement through observed fringes.
What spectroscopy measures
Covers the principles of MR spectroscopy and measuring biochemical compounds in vivo.
Optical Grating: Resolving Sodium Doublet Wavelengths
Explores using an optical grating to resolve sodium doublet wavelengths.
Related MOOCs (3)
Micro and Nanofabrication (MEMS)
Learn the fundamentals of microfabrication and nanofabrication by using the most effective techniques in a cleanroom environment.
Microstructure Fabrication Technologies I
Learn the fundamentals of microfabrication and nanofabrication by using the most effective techniques in a cleanroom environment.
Micro and Nanofabrication (MEMS)
Learn the fundamentals of microfabrication and nanofabrication by using the most effective techniques in a cleanroom environment.