This paper reports on an experiment about a novel method of polarization stabilization.The polarization stabilizer proposed here has an additional function of polarization transformation from any state of polarization into any others.The particle swarm optimization is introduced as a control algorithm in the process of either searching or endless tracking.The tracking speed of the stabilizer is obtained up to 12.6 krad/s by using hardware we have in the laboratory,which means that we can achieve a higher speed practical polarization stabilizer if we have faster hardware.
A new cross-tracking method is proposed to improve the convergent speed of the control algorithm in real-time polarization mode dispersion(PMD)compensation systems.The cross-tracking algorithm is compared with the previously used dithering particle swarm optimization(DPSO)and gradient particle swarm optimization(GPSO)algorithms,and it is proven to offer the best performance among the three algorithms.The transmission of a 43-Gb/s differential quadrature phase-shift keying(DQPSK)signal over a 1 200-km fiber span using a compensator based on digital signal processing(DSP)is demonstrated via the cross-tracking algorithm.
The adaptive polarization mode dispersion(PMD) compensation in high-speed transmission system has become more and more necessary for the link PMD causing strong signal distortions.A dynamic adaptive PMD compensator in 40 Gb/s polar-multiplex differential quadrature phase shift keying(PM-DQPSK) system is reported.Experimental results show that the PMD compensator can track the average polarization state variation at 65 rad/s without any lost of the optimum tracking.The 1st-order PMD compensation is demonstrated experimentally,and the compensator can increase the maximal tolerable PMD value by 26 ps from 17 ps to 43 ps in an optical transmission system.
