铌酸锂马赫-曾德尔调制器偏置工作点的一种锁定方法

A Bias Control Technique for Lithium Niobate Mach-Zehnder Modulators

本文提出了一种锁定铌酸锂马赫-曾德尔调制器(MZM)偏置工作点的方法 ,通过引入一个特殊的测试电压和校准马赫-曾德尔调制器的最大输出光强,反馈信号受输入光功率的波动和探测器的暗噪声影响很小,偏置锁定精度可以达到±0.05°(标准偏差)。这种方法可以锁定铌酸锂马赫-曾德尔调制器传递函数上的任意工作点,且不需要加入额外的扰动信号,可以应用于连续变量量子密钥分发等领域。

We propose a dither-free bias control technique for lithium niobate Mach-Zehnder modulators （MZM） which can be used in continuous-variable quantum key distribution. Due to the introduction of a specific test phase bias and calibration of MZM maximum output optical power, the feedback signal was insensitive to the system ＇s noises including the input optical power fluctuations and the dark noise of photodetector. The technique can be used to lock any arbitrary position along the MZM transfer function with a locking accuracy around ± 0. 05 degrees （standard deviation）.