Automatic polarization-mode dispersion compensation in 40-Gbit/s transmission

Abstract

IntroductionIn high-speed optical transmission systems beyond 10 Gbitls, signal distortion caused by polarization-mode dispersion (PMD) is a major limitation on transmission distance. PMD of the installed fibers fluctuates with time due to environmental influences, for example, changes in temperature and stress. Therefore, adaptive PMD compensation during system operation is indispensable [l]. There are two key requirements in realizing an automatic PMD compensation system. One is to monitor the state of polarization of the received optical signals without large-scale PMD measurement equipment. The other is the realization of an automatically controlled PMD compensator. In our 10-Gbitls NRZ transmission experiments, we already confirmed that the intensity of the half-frequency components of the bit rate in the received baseband signals can be used for PMD monitoring [2]. In this paper, we successfully demonstrated automatic PMD compensation in 40-Gbitls N E transmission for the first time. Using a PMD monitor of 20-GHz intensity extracted from the received 40-Gbitls NRZ baseband signals, we performed the feedback control of an optical PMD compensator consisting of a polarization controller and a polarizationmaintaining fiber.

Ultrafast optical technologies for large-capacity TDM/WDM photonic networks

“…Regarding the adaptive PMD equalization, there have been many demonstrations at 160 Gbit/s even in an installed fiber line. [6,32,60,82] …”

An Experiment of Adaptive PMD Compensation in 10 Gbit/s RZ Optical Communication System using PSO Algorithm

“…Theoretically, the electrical power of specific frequency component after band-pass filter is [3] o 3 4 Q_penalty |dB]…”

“…The adaptive PMD compensators are needed to be established to overcome this limitation. Several works [1][2][3][4][5] of adaptive polarization mode dispersion compensation experiments have been reported. In our previous work, we have realized PMD compensation with manual techniques [6].…”

Numerical Modeling of PMD

“…The dots in Fig. 2(a) shows the data for a 10 Gb/s system (see [23]). However, since the x-axis is normalized by the bit-period, T b , and PMD is a linear impairment, the results also apply for a 40 Gb/s system.…”