Search results
Results from the WOW.Com Content Network
They are used to express distances in terms of the numerical aperture of the system and the wavelength of the light used for observation. Using these units allows comparison of the properties of different microscopes. [1]
It is widely used in optical engineering laboratory work to analyze and validate imaging systems such as microscopes, cameras and image scanners. [ 1 ] The full standard pattern consists of 9 groups, with each group consisting of 6 elements; thus there are 54 target elements provided in the full series.
The optical microscope, also referred to as a light microscope, is a type of microscope that commonly uses visible light and a system of lenses to generate magnified images of small objects. Optical microscopes are the oldest design of microscope and were possibly invented in their present compound form in the 17th century.
In interferometric microscopy, the image of a micro-object is synthesized numerically as a coherent combination of partial images with registered amplitude and phase. [ 1 ] [ 2 ] For registration of partial images, a conventional holographic set-up is used with a reference wave, as is usual in optical holography .
The single lens with its attachments, or the system of lenses and imaging equipment, along with the appropriate lighting equipment, sample stage, and support, makes up the basic light microscope. The most recent development is the digital microscope, which uses a CCD camera to focus on the exhibit of interest. The image is shown on a computer ...
In both cases the numerical aperture of the objective is 1.49 and the refractive index of the medium 1.52. The wavelength of the emitted light is assumed to be 600 nm and, in case of the confocal microscope, that of the excitation light 500 nm with circular polarization. A section is cut to visualize the internal intensity distribution.
The ability of a lens to resolve detail is usually determined by the quality of the lens, but is ultimately limited by diffraction.Light coming from a point source in the object diffracts through the lens aperture such that it forms a diffraction pattern in the image, which has a central spot and surrounding bright rings, separated by dark nulls; this pattern is known as an Airy pattern, and ...
The observation of sub-wavelength structures with microscopes is difficult because of the Abbe diffraction limit.Ernst Abbe found in 1873, [2] and expressed as a formula in 1882, [3] that light with wavelength , traveling in a medium with refractive index and converging to a spot with half-angle will have a minimum resolvable distance of