Procedure for measuring time delays with respect to the delay of the differential mode, DMD, of a multi-mode fiber, MMF, or a few-mode fiber, FMF

摘要

Procedure for measuring time delays with respect to differential mode delay, DMD, of a multi-mode fiber, MMF (6), or low-mode fiber, FMF (6), for at least two different wavelengths in one measuring installation (1), said measuring installation comprising a laser device (2) arranged to emit laser pulses in said at least two different wavelengths, a single mode fiber, SMF (4), arranged to couple pulses lasers emitted in said MMF or said FMF, a first component (3) arranged to couple laser pulses emitted by said laser device to said SMF, a second component (5) arranged to align said SMF with said MMF or said FMF, a detector module (8) arranged to detect outgoing laser pulses from said MMF or FMF, and a third component (7) arranged to couple said emitted laser pulses, outgoing from said MMF or said FMF, to said detector module, comprising said procedure the following steps a), b), c): a) providing said MMF or said FMF to said measuring facility and aligning, by said second component, said SMF with said MMF or said FMF; b) carry out first measurements with respect to a first radial displacement value, by: - positioning, by said second component, said SMF in said MMF or said FMF in said first radial displacement value; - emitting, by said laser device, said laser pulses in said at least two different wavelengths; - measuring, by means of said detector module, said time delays of said emitted laser pulses, projections of said MMF or said FMF, individually for each of said at least two different wavelengths; c) carry out second measurements with respect to an additional radial displacement value, by means of: - positioning, by said second component, said SMF in said MMF or said FMF, in said additional radial displacement value, said radial displacement being additional different from said first radial displacement value; - emitting, by means of said laser device, said laser pulses in said at least two different wavelengths; - measuring, by means of said detector module, said time delays of said emitted laser pulses, projections of said MMF or said FMF, individually for each of said, at least two, different wavelengths.