Multimode Numerical Aperture (NA)
Numerical aperture (NA) is an important characteristic in a multimode fiber. It defines the maximum angle at which a fiber can accept the light that needs to be transmitted through it. The higher an optical fiber's NA, the larger the cone of light that can be injected into its core.
The major advantage of Graded-index multimode fiber is that it has a relatively high NA. This means it can be used with relatively low cost optical components and light sources that have large spot sizes and which can be easily coupled to the core.
The 'Production/Lab/R&D' range is suitable for manufacturers of fiber and cables. It is considered unlikely that this measurement would be required in a field environment.