Experimental Analysis of Mach-Zehnder Modulator’s Bias Point Enabling Long Distance Transmission Using a Recirculating Fiber Loop

We discuss the use of an optical recirculating loop for the experimental analysis of a Mach-Zehnder Modulator’s point of operation over numerous transmission distances. For this analysis DDO-OFDM signals are employed, obtaining a nominal rate of 1.41 Gb/s over 600 km, without dispersion compensation. Under these conditions, the point of operation was analyzed, demonstrating how this parameter should be optimized in order to allow better performance over long transmission distances.