Cut off Wavelength for Single mode Fiber Calculator

Calculate the cut-off wavelength for single-mode fibers based on core diameter and numerical aperture

Input Parameters

Calculation Results

Calculation Formula

λc = 2.405 × (π × core_diameter) / (2 × NA)2

Where:
λc = cut-off wavelength (μm)
core_diameter = core diameter of the fiber (μm)
NA = numerical aperture

Cut off Wavelength for Single mode Fiber Calculator Usage Guide

Learn how to use the cut-off wavelength calculator for single-mode fibers

How to Use This Calculator

  1. Enter the core diameter of your single-mode fiber in micrometers (μm). Common values range from 8.3 to 10.5 μm.
  2. Enter the numerical aperture (NA) of your fiber. This value is typically between 0.12 and 0.15 for standard single-mode fibers.
  3. Click the "Calculate" button to compute the cut-off wavelength.
  4. The cut-off wavelength is the minimum wavelength at which single-mode operation begins in the fiber.

Understanding the Cut-off Wavelength

The cut-off wavelength is the minimum wavelength for which a fiber supports only a single mode of propagation. Below this wavelength, the fiber will support multiple modes, leading to modal dispersion and signal degradation.

Example Calculation

For a fiber with a core diameter of 9.0 μm and a numerical aperture of 0.14:

λc = 2.405 × (π × 9.0) / (2 × 0.14)2 = 1038.6 μm

This means that at wavelengths shorter than approximately 1038.6 μm, this fiber would support multiple modes.

Applications

  • Optical communication systems design
  • Fiber optic sensors
  • Telecommunications infrastructure planning
  • Optical testing and measurement