SCHOTT North America

Technical Data

Numerical Aperture

The numerical aperture of a light-conducting fiber depends on the refractive index of the core and cladding glass used. In single fibers where light beams intersect to optical axis the following equation can be used:

n₀ = refractive index of the surrounding medium
n₁ = refractive index of the fiber core
n₂ = refractive index of the fiber cladding
α₀ = critical angle to the optical axis

All light beams which strike the perpendicular polished end of a fiber within a defined incident angle are transmitted along the length of the fiber.

SCHOTT offers fibers with a wide range of numerical aperture, covering most applications.