Abstract

The frequency chirping caused by direct laser modulation limits the transmission bandwidth of a single-mode fiber system, even when we employ a directly modulated dynamic-single-mode laser. To eliminate this problem, some types of external intensity modulator, such as those employing electroabsorption^1,2 and electrooptic effects³ have been studied. We have pointed out that frequency chirping is caused by phase modulation due to a refractive-index change in a loss modulator.⁴

© 1987 Optical Society of America