A scheme, using two-single drive Mach–Zehnder modulators (SD-MZMs) to generate flat optical frequency comb (OFC) by an analogue driving signal, is experimentally demonstrated. The modulator is used to add equidistant sidebands to an injected carrier continuous-wave laser centred at 1550 nm. The flatness of the comb lines is achieved by tuning the DC bias voltages supplied to both modulators. Five comb lines are tested for different frequency spacing of 8.5, 10, 11.5, and 12 GHz and show good frequency tunability. Also, the effect of increasing the radio frequency (RF) modulation signal power on the number of comb lines is investigated. A total of 5 comb lines are obtained with a repetition rate of 10 GHz and 0.77 dB flatness. The proposed system is simple and cost-effective due to the utilization of a simple Mach–Zehnder modulator structure driven by one RF signal generator.

实验证明了一种使用两个单驱动马赫-曾德调制器 (SD-MZM) 通过模拟驱动信号生成平坦光频梳 (OFC) 的方案。调制器用于向中心为 1550 nm 的注入载波连续波激光器添加等距边带。梳状线的平坦度是通过调整提供给两个调制器的直流偏置电压来实现的。5 条梳状线针对 8.5、10、11.5 和 12 GHz 的不同频率间隔进行了测试，并显示出良好的频率可调性。此外，还研究了增加射频 (RF) 调制信号功率对梳状线数量的影响。共获得 5 条梳状线，重复率为 10 GHz，平坦度为 0.77 dB。