Numerical aperture: A calculation that shows the ability of an objective lens to make fine structural detail in the specimen distinct (N.A.
Researchers have also begun to seek options for a fourth-generation optical recording medium that could be based on near-field optics (with a
numerical aperture of 1.4 or even 2).
These systems offer the advantage of polymeric material with no low molecular weight additives, a controlled
numerical aperture up to about 0.25 and low moisture absorption.
As might be guessed by looking at the markings on any objective lens, the magnification and
numerical aperture are important for the image-formation properties of an optical microscope.
In this case, transverse resolution is not defined through the
numerical aperture NA of the fiber, and consequently, through Rayleigh limit (about 0.6[lambda]/NA).
An angle of 30[degrees] is at the edge of a solid angle corresponding to a
numerical aperture (NA) of 0.5.
Numerical aperture refers to the light gathering ability plus the resolving power of the lens.
1 A 100 Mb/s multimode optical fiber data link, up to 2 km, taken from the FDDI physical medium dependent specifications: Nominal core diameter: 62.5 Cladding diameter: 125.0 [+ or -] 3.0 Modal bandwidth (1,300 nm): 500 MHz/km Attentuation for link, including component loss (1,300 nm): 11.0 dB Nominal
numerical aperture: 0.275
With active cooling, the 2400B-405 model can emit greater than 20W from a 7.5mm diameter clear aperture with a 0.66
numerical aperture (NA).
They are also available in higher
numerical aperture designs.
A phase ring has been incorporated into the microscope's body to speed the attachment of high
numerical aperture objectives and to prevent light loss.