Accurate fiber skew measurements by a phase method

Recently, an optical parallel transmission using fiber ribbons has been investigated. The important parameter for optical parallel transmission systems is skew and recent fiber ribbon manufacturing technologies make the skew value low. Therefore, the accurate skew measurements for these low skew fiber ribbons become very important. In this paper, we discuss the accurate skew measurements by the phase method. Phase fluctuations are measured for two types of lasers, a DFB-LD and a FP-LD, to clarify the light source dependence. Phase fluctuations are also investigated theoretically, based on the lasing mode fluctuations (mode partition. Fluctuations using an ordinary single mode fiber and a dispersion shift fiber (DSF) are measured and the measured results are in good agreement with the theoretical ones.