中国激光, 2015, 42 (9): 0905004, 网络出版: 2015-09-06
大调制信号马赫-曾德尔调制器偏置电压控制技术 下载: 588次
Mach-Zehnder Modulator Bias Controller for Large Modulation Signal
光学器件 马赫-曾德尔调制器 偏置电压控制 谐波 大调制信号 optical devices Mach-Zehnder modulator bias controller harmonic wave large modulation signal
摘要
马赫-曾德尔调制器的工作特性随温度变化等环境因素影响严重,因此需要设计专用的偏置电压控制电路。利用扰动输入和谐波探测相结合的偏置电压控制方案是一种比较好的解决方案,但传统的控制架构在面对大调制信号输入时,往往会出现锁定点严重漂移的现象。首先对谐波产生的机制的进行了理论建模,然后对传统的谐波检测架构进行了分析,发现大信号调制下的以往谐波分量计算公式以不再适用,必须加以改进,因此在改进谐波计算公式的基础上,提出了一种新的可用于大信号调制下的偏置点控制技术,并研制了相应的驱动电路,对电路的偏置点控制测试结果发现,提出的方案偏置点的控制精度在1°以内,可以很好地满足大调制信号输入的应用需求。
Abstract
The operating characteristic of Mach-Zehnder modulator is influenced severely by environmental factors such as temperature changing. Therefore, a bias controller is required to stabilize the operating point automatically. Applying a dither signal and detecting its harmonic wave to measure the position of operating point is a useful method. However, when the amplitude of modulation signal is large, the prior art method fails to lock the bias point. The harmonic wave resulting from modulation transfer function has been simulated and analyzed. It is shown that previous harmonic wave calculation formulate will not be suitable when a large modulation signal inputs. Therefore, we have modified the calculation method and proposed a bias controller with new architecture to maintain the working point in large modulation signal condition. At last, we have developed corresponding circuit, and test result shows that our method can lock the working point within accuracy of 1°, which is quite useful in large modulation signal application.
周鹏威, 李廷安, 郭云峰, 孙志强, 庄茁. 大调制信号马赫-曾德尔调制器偏置电压控制技术[J]. 中国激光, 2015, 42(9): 0905004. Zhou Pengwei, Li Ting′an, Guo Yunfeng, Sun Zhiqiang, Zhuang Zhuo. Mach-Zehnder Modulator Bias Controller for Large Modulation Signal[J]. Chinese Journal of Lasers, 2015, 42(9): 0905004.