PMD Calibration Artefacts
NPL has developed facilities to measure polarisation mode dispersion (PMD) and other polarisation properties of optical fibres, optical fibre components and systems. These facilities include capability for polarisation dependent loss (PDL), polarisation dependent response (PDR) and polarisation dependent gain (PDG) measurement. To complement these facilities a calibration standard for polarisation mode dispersion (PMD) measurement equipment has been produced.
PMD Measurement
Measurements are analysed using the arc on the Poincaré sphere method where the principle state of polarisation is determined and the rate of rotation of the output polarisation about the principle state gives the differential group delay. The PMD is calculated from the root mean squared differential group delay over the wavelength range. It is also possible to calculate the second order PMD.
PMD Calibration Artefacts
NPL has developed PMD calibration artefacts as transfer standards for PMD measurements. These fall into two categories, low mode coupled standards based on HiBi fibre and a high mode coupled artefact based on a multi-waveplate stack.
Low Mode Coupled Standard
These are suitable for the calibration of all types of PMD measurement equipment and give a single fixed DGD (Differential Group Delay) calibration point. Calibration artefacts with DGD in the range 0.3 ps to 15 ps can be produced with a calibrated measurement uncertainty of ± 2%.
A copy of a typical Calibration Certificate is available.
High Mode Coupled Standard
These are only suitable for the calibration of PMD measurement equipment, which measures DGD as a function of wavelength, and can calculate PMD in specific wavelength ranges. This applies to the polarimeter based PMD measurement methods (Jones Matrix, Muller Matrix and Poincaré Sphere Analysis). The artefact is based on a stack of 32 quartz waveplates with pseudo random orientations that provides a PMD of ~0.5 ps.
Contact
Customer Service tel: +44 20 8943 8637
E-mail: fibreoptics_enquiries@npl.co.uk