Simple adaptive first‐order PMD compensator using a Faraday rotator and a variable DGD element

Abstract

AbstractA two‐degree‐of‐freedom (DOF) polarization mode dispersion (PMD) compensator has been developed to cancel the effects of first‐order PMD. The compensator comprises of a Faraday rotator (FR) and a dynamically varying crystal differential‐group‐delay (DGD) element. Because of the reduced number of control parameters, the compensator potentially possesses the desirable features of simple control, fast response, and cost saving. Principle of operation is validated by theoretical analysis and successful automatic PMD compensation is achieved in a 40 Gbit/s nonreturn‐to‐zero (NRZ) system. The compensator increased the average DGD allowed from less than 23% per bit‐slot for the uncompensated case to 42% at an outage probability of 10−4. Fast response of the compensator is also observed. The optimum setting of the compensator can be found in about 10 nregulating steps for all PMD emulator (PMDE) setting. These features allow the effective mitigation of the first‐order PMD effects within an optical fiber channel. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2417–2420, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23669