MULTILEVEL POLARIZATION MODULATION USING A SPECIFICALLY DESIGNED LINBO3 DEVICE

Binary and multilevel optical polarization modulation (POLSK) is an in novative transmission technique, suitable for both coherent and direct detection. To prove its feasibility, we have built a flexible polariz ation modulator based on a specifically designed LiNbO3 device. We sho w that it can generate any state of polarization and therefore it is s uitable for transmission of any binary or multilevel POLSK constellati on. Once electrically equalized, the modulator has a 4 GHz bandwidth. To test the modulator with actual digital modulation, we set up a cohe rent binary experiment at 800 Mbit/s, and attained a sensitivity 1.5 d B away from the noise limit of the receiver.