Patent ID: 7221439

Claim:
A method for measuring longitudinal variation in chromatic dispersion in an optical fiber, comprising: (i) launching a first signal into a first end and a second signal into a second end of said optical fiber, at a wavelength λ 1 , to collect back-scatter power P(z) measurements for different positions z within said optical fiber and providing measured OTDR backscatter traces generated by the time generated by an optical time domain reflectometer; (ii) deriving either a longitudinal MFD(z) data or a relative MFD data from the OTDR backscatter traces, at a single OTDR wavelength λ 1 ; and (iii) calculating estimated longitudinal dispersion D(z) of the fiber from either said longitudinal MFD(z) data or said relative MFD data derived from the OTDR backscatter traces generated by the time generated by an optical time domain reflectometer, at the wavelength λ 1 , without utilizing any other wavelength data.