Design and optimization of ultra-flat optical frequency comb generation using dual-drive lithium niobate Mach–Zehnder modulators for high-capacity WDM communication systems
摘要
This paper presents a new technique to generate a flattened Optical frequency comb (OFC) using two Dual-Drive Lithium Niobite Mach–Zehnder Modulators. A total of 125 channels were successfully generated by modulating a Continuous-wave laser with a 10 GHz RF signal operating using OptiSystem 7 software. Several variables were modified to examine their effect on the number of comb lines, comb flatness, and channel spacing. The results showed that the required system objectives can be achieved by controlling the internal parameters of the modulator expressed by the RF switching and biasing voltages to 3 V and 10 V, respectively, to generate 125, 10 GHz equally spaced low power variation comb lines and a total bandwidth of 10 nm (1.24 THz). To evaluate the system performance, a WDM optical communication system was successfully used to transmit 20 Gbps/line over a 100 km transmission distance with a minimum error rate of 10–9 per channel, which indicates the successful use of the proposed comb generator in optical communication applications.