An assessment of the backscatter technique as a means for estimating loss in optical waveguides

Calibration and standardization issues for the optical time-domain reflectometer

“…These effects occur even if the instrument itself is error free i.e., is properly "calibrated". These limitations are well documented [5, 6,7].…”

Backscatter measurements on optical fibers

“…The degree of agreement between backscatter-derived loss determinations and the conventional cut-back loss values depends on measurement procedures as well as the intrinsic properties of the fiber. The procedures and conditions necessary for good agreement have been discussed at length elsewhere [18]; we will note here only that if the properties of the fiber are uniform (not a function of length) and reciprocal (the same in both forward and backward directions) then the losses determined from the cut-back and backscatter methods sould be equal.…”