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Simultaneous first- and second-order adaptive PMD compensation in optical transmission systems

An adaptive double-stage PMD compensator capable of compensating first- and second-order PMD simultaneously is experimentally researched by introducing genetic algorithm for the first time. In order to verify the effect of the double-stage PMD compensator, an experimental optical transmission system at a bit rate of 10 Gbit/s is setup. In experiments, degree of polarization (DOP) of received optical signal is adopted for PMD monitoring. Experimental results show that genetic algorithm is effective and powerful in first- and second-PMD compensation. The DOP of received optical signals after PMD compensation can reach a value larger than 0.97 within 180 milliseconds during which genetic algorithm runs 50 iterations. PMD measurement indicates that the first- and second-order PMD in transmission link can simultaneously reach the minima after PMD compensation at the operation wavelength.