Adaptive compensation method for inhibiting bias point drift of Mach-Zehnder modulator

Abstract

The invention relates to an adaptive compensation method for inhibiting bias point drift of a Mach-Zehnder modulator. The method comprises the following steps of: adopting a thermal resistor to detect the environment temperature at a waveguide part of the Mach-Zehnder modulator; inputting a resistance value of the thermal resistor into a bias point control circuit of the Mach-Zehnder modulator, wherein the output quantity of the bias point control circuit of the Mach-Zehnder modulator is the bias voltage of the Mach-Zehnder modulator; establishing an expression about the environment temperature at the waveguide part of the Mach-Zehnder modulator of the bias voltage; and realizing the adaptive compensation that a bias point of the Mach-Zehnder modulator drifts along with the changes of theenvironment temperature by using the expression. The adaptive compensation method obtains a drift coefficient about environment temperature variable of the bias point of the Mach-Zehnder modulator bymeasuring the drift quantity of the bias point of the Mach-Zehnder modulator along with the changes of the environment temperature, and inputs the drift coefficient into the bias point control circuit of the Mach-Zehnder modulator to ensure that the bias voltage output by the control circuit changes along with the changes of the environment temperature.

Description

technical field [0001] The invention relates to a Mach-Zehnder modulator at a transmitting end in an optical fiber transmission system, in particular to an adaptive compensation method for suppressing the offset point drift of the Mach-Zehnder modulator. Background technique [0002] In a high-speed optical fiber transmission system, the transmitting end is composed of a distributed feedback laser, a Mach-Zehnder modulator, an RF signal input circuit, and a Mach-Zehnder modulator bias point control circuit. By setting the Mach-Zehnder modulator bias point, the intensity and Phase modulation, through cascaded Mach-Zehnder modulators to achieve multi-order amplitude-phase modulation. [0003] The bias point of the Mach-Zehnder modulator will drift with the change of the ambient temperature, and the drift of the bias point will affect the amplitude and phase of the output signal at the transmitter. It is necessary to take measures to stabilize the bias point of the Mach-Zehnder...

AI Technical Summary

Problems solved by technology

Since TEC temperature tuning is a dynamic equilibrium process, the local temperature of the waveguide will experience a temperature value near the target set point during the tuning process, causing the bias point of the Mach-Zehnder modulator to experience large fluctuations, affecting the Mach-Zehnder modulator. output performance

Images