Chromatic dispersion measurement in optical fibers using optoelectronic oscillations

In this paper, a novel technique is introduced that enables the measurement of chromatic dispersion (CD) in optical fibers. This technique is based on a relatively low-frequency optoelectronic oscillation (OEO) to provide a fast, precise and a relatively low-cost method for CD measurement that can be implemented easily in commercial instruments. In addition, another technique is introduced to compensate for the thermal fluctuations in fiber during measurement. The proposed setup is implemented to measure CD in normal single-mode fibers with lengths of 40 km, 10 km, and 1 km. Moreover, it is implemented to measure CD in 400 m of non-zero dispersion shifted fiber to test the system ability to resolve small chromatic delays. The proposed setup can resolve delays less than 0.1 ps/nm and measure CD with precision as low as 0.005 ps/nm·km over a wavelength range from 1500 to 1630 nm in only 20 s with 5 nm steps. The precision and the speed of measurement can be improved by increasing the wavelength steps to 10 nm.