A novel chromatic dispersion measurement method in frequency domain using a multi-wavelength optical pulse train generated by Fabry–Perot laser diode

Abstract

We propose and demonstrate a simple and robust measurement method for the chromatic dispersion of single mode fibers. Multi-wavelength picosecond optical pulse train from a gain-switched Fabry–Perot laser diode in conjunction with the highly dispersive fiber is used for multi-wavelength light source. The frequency of the separated pulse train may suffer a frequency change in dispersive optical fiber, which can be measured very accurately by an electrical spectrum analyzer. This method was applied to measure the chromatic dispersion of the standard single mode fiber for various lengths. The measured chromatic dispersion of a standard single mode fiber was 17.60 ps/nm/km at 1561 nm with an experimental standard deviation of 0.20 ps/nm/km and time resolution was less than 0.18 ps. The measurement setup is compact and economical compared to conventional methods. This technique can be applied in both long and short lengths (∼50 m) of fibers with very high accuracy.