Abstract

With the increased transmission speed of wavelength division multiplexing (WDM) systems, accurate measurements of chromatic dispersion (CD) of optical fiber and WDM components become very important. Such measurements are commonly carried out using modulated phase-shift technique.¹ In this scheme, a vector network analyzer is normally used to generate a modulation signal and to detect its phase shift.² Although it provides high phase accuracy and good resolution, the cost of the system is high. Baseband AM response method has been reported in³to measure the fiber dispersion using a scalar network ana-lyzer. However, since this method requires a wide sweep frequency range (20 GHz), the high-speed modulator, wideband photodetector and high-frequency scalar network analyzer are necessary. These significantly increase the system cost and complexity. At the same time, the measurement accuracy is degraded for the high noise level related to the wideband photodetector.⁴

© 2002 Optical Society of America