How to use the fiber optic numerical aperture calculator
Find numerical aperture and acceptance angle of an optical fiber. Enter core index, cladding index in the fields above; the numerical aperture, acceptance angle are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- n1 — Core index
- n2 — Cladding index
Worked example
With core index = 1.48, cladding index = 1.46, the calculator gives numerical aperture ≈ 0.2424871; acceptance angle ≈ 14.03338 °.
Frequently asked questions
What is the formula for the fiber optic numerical aperture calculation?
Numerical aperture = √(n1 × n1-n2 × n2). Acceptance angle (°) = asin([Numerical aperture]). Here n1 is core index, n2 is cladding index.
What inputs do I need for the fiber optic numerical aperture calculator?
You need core index, cladding index. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.