Interlaboratory measurement comparison to determine the attenuation and bandwidth of graded-index optical fibers

An interlaboratory measurement comparison was conducted by the National Bureau of Standards in cooperation with the Electronic Industries Association. Participants included NBS and nine optical fiber and cable manufacturers. Four graded-index fibers having lengths of 2, 2, 2, and 0.9 km were used. Measurements of attenuation at 850 nm, using both beam optics and mode filter approaches to achieve a restricted launch, gave one standard deviation spreads of 0.24, 0.12, 0.12, and 0.43 dB/km for an overall average of 0.23 dB/km. Best measurement agreement was obtained for a fiber having little differential mode attenuation. Measurements of -3-dB bandwidth from time domain acquired data at 90 nm gave an average one standard deviation spread of 12% with poorer agreement on the higher frequency portion of the frequency response.