A self-adaptive control method of mz modulator bias voltage

Abstract

The invention discloses an MZ modulator bias voltage self-adaption control method. The method comprises the following steps that 1, the output light power of each sampling time point in a sampling time window is measured, the average light power of the bias voltage is solved, the bias voltage is increased by one stepping voltage to obtain an average light power corresponding to the current bias voltage, then the partial derivative of the average light power to the bias voltage is solved, sampling is repeatedly conducted, the partial derivative is solved for multiple times, and averaging is conducted to obtain the average partial derivative to serve as a bias point monitoring parameter; 2, the sampling time window is gradually widened and the partial derivative averaging time number is gradually increased until an absolute value of a difference between the bias voltage control error and the previous control error and an absolute value of a difference between the bias voltage control error and the next control error meet the error requirement separately, and the corresponding sampling time window and partial derivative averaging time number at the moment are taken as optimal values; 3, bias point monitoring is continuously conducted on the basis of an average partial derivative by taking the optimal sampling time window and partial derivative averaging time number as fixed values. According to the method, the noise influence is reduced, the bias voltage control precision is improved, and meanwhile the shorter feedback time is achieved.

Description

technical field [0001] The invention belongs to the technical field of optical communication, and more specifically relates to an adaptive control method for bias voltage of an MZ modulator. Background technique [0002] With the development of high-speed optical communication, the Mach-Zehnder (MZ) modulator, as a key device in generating optical signals with various modulation formats, is more and more widely used in this field. The MZ modulator is composed of two waveguide arms and two Y-shaped branches. Using the principle of electro-optic effect of crystal materials, the two arms produce an optical path difference by adjusting the electric field on the two waveguide arms. The ports for loading the electric field are divided into radio frequency and At the DC bias end, the phase modulation is transformed into intensity modulation after interference occurs. During the working process of the MZ modulator, due to the influence of the external environment, such as temperatu...

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