INTERLABORATORY COMPARISON OF MODE TRANSITION MATRICES

An interlaboratory measurement round-robin was conducted by the Univer sity of Colorado and three industrial members of the Electronic Indust ries Association. A computational definition of mode transition matric es (MTM's) is presented, and its relationship to the basic theory of p ower propagation in multimode fibers is detailed. Measured data from t he round-robin were used to calculate MTM's for the test components, w hich included four connectors, two sections of fiber cable, two power splitters, and two short fiber segments. The diagonal elements of the (2 x 2) MTM's determined from the near-field data were found to have a laboratory-to-laboratory standard deviation of approximately 10% of t he average value. The off-diagonal elements were found to have a stand ard deviation approaching their mean value. The inherent launch depend ence of MTM's is investigated as a source of the observed variation. O ther sources of uncertainty such as errors in determining the core rad ius are also considered. Finally the implications of these results for the problem of characterizing components' intensive multimode fiber s ystems are discussed.