Optical IQ modulator arbitrary bias point control method and system

Abstract

The invention discloses an optical IQ modulator arbitrary bias point control method and system. The control method comprises: calculating a first type of correlation integral coefficient by using a first disturbance signal and a second disturbance signal; obtaining the characteristic voltage rough values of respective modulators according to a relationship between bias voltages and the first typeof correlation integral coefficients; obtaining the characteristic voltage accurate values of respective modulators by using an iterative method and the characteristic voltage rough values of respective modulators; calculating the bias voltages required to be loaded onto respective modulators at a target bias point, and correspondingly setting the bias voltages required to be loaded onto respective modulators; calculating the value of a second type of correlation integral coefficient by using a third disturbance signal, and accordingly calculating a reference correlation coefficient vector; obtaining a real-time correlation coefficient vector, calculating an error voltage, and then correspondingly adjusting the bias voltages of respective modulators by using the error voltage. The method and system can control any bias point of an optical IQ modulator and maintain the stability of the bias point.

Description

technical field [0001] The invention belongs to the fields of optical fiber communication and microwave photonics, and more specifically relates to a method and a control system for controlling an arbitrary bias point of an optical IQ modulator. Background technique [0002] In optical fiber communication systems, in order to increase channel capacity and increase spectral efficiency, high-order modulation formats such as QPSK, 16QAM, and 64QAM have been widely used. In order to generate an optical signal in a high-order modulation format, an optical in-phase / quadrature-phase (IQ) modulator has been widely used. In addition, because the optical IQ modulator can generate a variety of high-order harmonics when it works at a nonlinear point, the field of microwave photonics also uses the optical IQ modulator to generate multi-frequency radio frequency microwave signals. In order to realize the modulation of signals in high-order modulation formats, the optical IQ modulator nee...

AI Technical Summary

Problems solved by technology

At present, the optimal linear point control of the optical IQ modulator and the arbitrary bias point control of the single MZM modulator have been extensively studied, but these control methods cannot realize the control of the arbitrary bias point of the optical IQ modulator and Maintain the stability of the bias point

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