调制器低偏置方案优化光电振荡器相位噪声

Optimization of Phase Noise of Opto-Electronic Oscillator Through Low-Biasing Technology for Modulator

提出了采用调制器低偏置方案来降低光电振荡器(OEO)的相位噪声方案并得到了实验验证。调制器的大光功率注入与低偏置点设置能够降低噪信比,进而降低输出信号的相位噪声。实验证明,当60mW光功率注入时,在低偏置点能得到相噪的最低值,该值比正交偏置点对应的相噪值下降了2.8dB。

A novel method for reducing the phase noise of the opto-electronic oscillator （OEO） is proposed and experimentally demonstrated. As for a given single-loop OEO, its phase noise characteristics are determined by the noise-to-signal ratio （NSR） which can be reduced by optimizing the direct current （DC） bias voltage of the modulator. Results show that, when the injected optical power equals to 60 mW, the minimum single sideband （SSB） phase noise at the low bias point is gotten which decreases by 2.8 dB than that at the quadrature bias point of the electro-optic modulator.