National Physical Laboratory

Optical Fibre Refractive Index

Multi-step index reference fibre

NPL can supply a 10 metre length of specially designed optical fibre with a multi-step refractive index profile. This fibre can be used to calibrate the refractive index difference scale of a customer’s profiler. In addition the intermediate steps can be used to assess non-linearity. The refractive index profile is shown below.

Multi-step Index FibreProfile of the NPL multi-step index fibre 

Typical measurement uncertainties:

  • Refractive index difference: 1.5% (or 0.000 1 if greater)
  • An example Calibration Certificate is available to download


Customer Service tel: +44 20 8943 8637

Last Updated: 25 Mar 2010
Created: 26 Jul 2007


Please note that the information will not be divulged to third parties, or used without your permission