标签: polarizer-related

Polarizer-relatedJOURNALOFLIGHTWAVETECHNOLOGY,VOL.8,NO.3,MARCH1990459PolarizationControlforCoherentFiber-opticSystemsUsingNematicLiquidCrystalsAbstract-Oneoftheobstaclestocoherentfiber-opticcommunicationsistheunpredictablepolarizationdriftwhichnecessitatestheuseofanactivepolarizationcontrollingsystemtomatchthepolarizationsofthesignalandlocaloscillator.Thepolarizationmatchmustbemaintainedduringtheresetofanyofthefiniterangecomponentstopreventlossofdata.Anovelandpracticalsystemwhichusesthreeliquidcrystaldevicesforthepolarizationmatchingprocessispresented,andtherequiredresetcontrolalgorithmanditsderivationaredescribedindetail.I.INTRODUCTIONODERNfiber-opticcommunicationssystemsemploydirectdetecti……