Research On Bias Voltage Control Algorithm Of The Electro-Optic Modulator

Nowadays, modulation technique is widely used in the field of optical communication.The electro-optic modulator is used in the process of optical communication. It is based on modulation technique. The bias voltage of the electro-optic modulator, decides its working point. To make the modulation signal working without distortion, and complete the linear modulation, the working point should be on the ideal point.The theme is based on the working theory and request of the electro-optic modulator.Analysis the relationship between the bias voltage and working point, establish a automatic control system to control the bias voltage. Focus on the analysis of features of several control algorithms. According to external disturbances, the change of parameters of the modulator and working point drift,the theme puts forward successive recursion and subsection-successive recursion adaption PID algorithm to control the bias voltage through constantly error testing. Then analysis the change of states in the algorithm.Then, establish the experiment environment, use programs to design the algorithm.Contrast the system with the algorithm and without the algorithm. Analysis the change of penetration rate in different experiments. The data of experiments illustrate that the successive recursion and the subsection-successive algorithms are effective. The subsection-successive recursion adaption PID algorithm can effectively stabilize the penetration rate when the working point is drifting, and guarantee the modulator works in the mid-point of linear area.