Abstract

Precise measurements of the baseband frequency response of multimode fibers are required in order to characterize them and to predict their behaviour when designing optical fiber transmission systems. Until about the middle of the '70's, these measurements had been performed mainly by the pulsebroadening technique (PBT) [1]. Recently, however, improvements in laser diode characteristics, such as in stable CW-operation and in wide-bandwidth modulation, has enabled us to apply effectively the swept-frequency method (SFM) to such fiber bandwidth measurements [2] [3].