DIN EN 60793-1-42:2013-10

This part of DIN EN 60793 establishes uniform requirements for measuring the chromatic dispersion of optical fibres. This measurement is intended to assist in the inspection of fibres and cables for commercial purposes. This International Standard describes three methods for measuring chromatic dispersion: - With the method of phase shift and using the relative phase shifts within a determined wavelength range the spectral group delay data are determined, which are intended as basis for the calculation of coefficients of an equation describing the dispersion specified for the respective fibre category. - With the method of spectral group delay in the time domain the time difference of pulse delays through a known fibre length is measured at various wave lengths. The relative spectral group delay data may be determined by subtracting a measured reference value for a short fibre and on that basis the dispersion values may be determined by finding out the coefficients of an equation specified for the respective type of fibre. - With the method of differential phase shift a single dispersion value at a particular wavelength is determined from the differential group delay between two closely spaced wavelengths. Average chromatic dispersion over the interval between the two wavelengths is determined from differential phase shift, wavelength interval and fibre length. The responsible committee is DKE/UK 412.6 "Lichtwellenleiter und Lichtwellenleiterkabel" ("Optical fibres and optical fibre cables") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.