Method and device for digitally and automatically controlling bias voltage of electro-optic light modulator

Abstract

The invention discloses a method and a device for digitally and automatically controlling bias voltage of an electro-optic light modulator. The method comprises the following steps: after inputting scanning bias voltage to a light modulator, calculating to obtain half-wave voltage of the light modulator; calculating error feedback coefficients and the dithering amplitude of a dithering signal according to the half-wave voltage; after inputting working bias voltage and the dithering signal to the light modulator, calculating to obtain harmonic amplitude and an offset phase; according to the offset phase, combining the error feedback coefficients, the harmonic amplitude and the working bias voltage to calculate to obtain new bias voltage; after taking the new bias voltage as the working bias voltage, returning the step for inputting the working bias voltage to the light modulator. According to the method for digitally automatically controlling the bias voltage of the electro-optic light modulator, in a light modulator working procedure, the working bias voltage can be continuously corrected, so that the working performance of the light modulator is more stable; furthermore, when the new bias voltage exceeds a voltage threshold range, the new bias voltage is modulated back, so that the working bias voltage is prevented from being too high or too low.

Description

technical field [0001] The invention relates to the field of light processing technology, in particular to a digital automatic bias voltage control method and device for an electro-optical light modulator. Background technique [0002] The optical modulator is used to modulate the radio frequency signal and the optical carrier output by the laser to form an optical signal. Among them, the optical modulator is widely used in the fields of optical fiber communication and optical fiber sensing. The output curve of the optical signal modulated by the optical modulator is a waveform in the shape of a cosine function. In order for the light modulator to be controlled at different operating points, a bias voltage can be output to the light modulator. [0003] However, since the optical modulator is extremely sensitive to changes in the working environment, changes in the working environment, such as temperature changes, humidity changes, mechanical vibrations, etc., will cause the...

AI Technical Summary

Problems solved by technology

However, the bias control technology is mainly developed based on the analog circuit scheme, which is susceptible to environmental noise interference, poor stability, and high error rate

In addition, the error feedback coefficient of the bias voltage technology in the prior art is fixed, and the half-wave voltage of different types of optical modulators may have a difference of 3 times, so the fixed error feedback coefficient cannot guarantee that the controller can be applied to different models There is a consistent effect on the optical modulator, which requires intermittent debugging of the device during use, which cannot achieve true automatic control and is not suitable for industrial applications

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