Fiber NA Calculator

Calculate numerical aperture, acceptance angle, and relative index difference for optical fibers from core and cladding refractive indices.

Fiber Preset
Refractive Indices
Numerical Aperture
NA
0.1246
Weakly guiding approx NA
n\u2081\u221a(2\u0394)
0.1248
Acceptance Angle
Half-angle \u03b8\u2090
7.16\u00b0
Full cone angle
14.32\u00b0
Index Difference
Relative index \u0394
0.00361
Abridged Optics — Fiber NA Calculator v1.0NA = \u221a(n\u2081\u00b2 \u2212 n\u2082\u00b2). \u03b8\u2090 = arcsin(NA). \u0394 = (n\u2081 \u2212 n\u2082)/n\u2081.

All information, equations, and calculations have been compiled and verified to the best of our ability. For mission-critical applications, we recommend independent verification of all values. If you find an error, please let us know.