If the space between the objective lens and the specimen is filled with oil however, the numerical aperture can obtain values greater than unity.
32.
By recording data with a numerical aperture objective of 1.4 NA and a wavelength of a capacity of 360 TBytes can be achieved.
33.
In this case, the numerical aperture is related to what is sometimes called the " working-number " or " effective-number ".
34.
This refers to the numerical aperture with respect to the extreme exit angle of a ray emerging from a fiber in which equilibrium mode distribution has been established.
35.
With an optical microscope having a high numerical aperture and using oil immersion, the best possible resolution is 200 nm corresponding to a magnification of around 1200?
36.
For a high numerical aperture lens, equivalent to a wide aperture, the depth of field is small ( shallow focus ) and gives good optical sectioning.
37.
Without this oil layer, not only is maximum numerical aperture not realized, but the condenser mat not be able to precisely focus light on the object.
38.
A stable trap requires that the gradient force, which is dependent upon the numerical aperture ( NA ) of the objective, be greater than the scattering force.
39.
Numerical aperture for microscope lenses typically ranges from 0.10 to 1.25, corresponding to focal lengths of about 40 mm to 2 mm, respectively.
40.
In a medium with an index of refraction close to 1, such as air, the angular aperture is approximately equal to twice the numerical aperture of the lens.
