numerical aperture


Also found in: Dictionary, Thesaurus, Medical, Legal, Financial, Acronyms, Wikipedia.

numerical aperture

[nü′mer·i·kəl ′ap·ə·chər]
(optics)
A measure of the resolving power of a microscope objective, equal to the product of the refractive index of the medium in front of the objective and the sine of the angle between the outermost ray entering the objective and the optical axis. Abbreviated N.A.

numerical aperture

The measurement of the acceptance angle of an optical fiber, which is the maximum angle at which the core of the fiber will take in light that will be contained within the core. Taken from the fiber core axis (center of core), the measurement is the square root of the squared refractive index of the core minus the squared refractive index of the cladding. See critical angle and fiber optics glossary.


The Acceptance Angle
The numerical aperture measures the acceptance angle of a fiber.
References in periodicals archive ?
This system can provide a maximum numerical aperture, NA = 0.
The diameter of a laser light depends on the Numerical Aperture (NA) of the lens.
Tenders are invited for Fiber Optic Setup for Numerical aperture.
With virtually all the same components as a conventional lithography setup, immersion lithography makes use of a liquid layer interposed between a lens and a silicon wafer's surface to improve resolution and increase the numerical aperture needed to effectively pattern features on the scale of 65-, 45-, and possibly 32-nm.
To help achieve a six to seven-fold increase in storage density over CD-R, two key components of the writing hardware needed to be altered: the wavelength of the recording laser and the numerical aperture (n.
0 [lambda] where [lambda] is the wavelength and NA is the numerical aperture of the lens.
The supply and in operation of a confocal laser scanning microscope, consisting of a fully motorized inverted microscope, lenses with high numerical aperture, a confocal scan head with at least three sensitive detectors, a detector for transmission of light, a minimum of 4 lasers with wavelengths between 405 and 633 lambda, incubation chamber for living cells and tissues, minimum 2 years of coverage for full service (both parts and working time).
Its engravings reveal its three major functions: the first step of magnification (the large number), the resolving power of the microscope (related to the numerical aperture, immediately following the magnification value), and contrast (PH for phase contrast, HMC for Hoffman Modulation Contrast, or DIC or IK for Nomarski/ interference contrast).

Full browser ?