Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
Opt Lett. 2011 Jul 15;36(14):2749-51. doi: 10.1364/OL.36.002749.
Optical frequency comb (OFC) generated using cascaded intensity and phase modulators was experimentally demonstrated. Very flat OFC can be achieved by cascading intensity and phase modulators driven directly by sinusoidal waveform, where chirped fiber Bragg grating or specially tailored radio frequency waveforms are not required. It is found that the spectral flatness of OFC is related to direct current (DC) bias of intensity modulator and the optimum ratio of DC bias to half-wave voltage is 0.35. In the experiment, 15 comb lines within 1 dB spectral power variation are obtained at 10 GHz microwave frequency. The experimental results agree well with the simulation.
实验演示了使用级联强度和相位调制器产生的光频梳（OFC）。通过级联直接由正弦波驱动的强度和相位调制器，可以实现非常平坦的 OFC，而不需要啁啾光纤布拉格光栅或专门设计的射频波形。研究发现，OFC 的光谱平坦度与强度调制器的直流（DC）偏置有关，DC 偏置与半波电压的最佳比值为 0.35。在实验中，在 10GHz 微波频率下获得了 15 个在 1dB 光谱功率变化范围内的梳状线。实验结果与模拟结果吻合较好。
