Device and method for stabilizing any bias point of external modulator

Abstract

The invention relates to a device and method for stabilizing any bias point of an external modulator, wherein the device comprises a laser, a variable optical attenuator, a lithium niobate modulator, an optical coupler, a signal source, a driving amplifier and a feedback control part; the device can be used for collecting a feedback signal and setting a bias voltage via a data acquisition board in the feedback control part so as to stabilize any bias point. The device and the method of the invention solve the problem that an optimal bias point of the modulator is drifted and an output signal is degraded because of changes of factors such as time, environment temperature, laser luminous power, and optical fiber inserting and coupling loss. The device and the method can be applied in the optical communication field, especially high-speed long distance communication in the optical communication field.

Description

technical field [0001] The invention relates to the field of optical communication, in particular to a device and method for stabilizing an arbitrary bias point of an external modulator. Background technique [0002] The most commonly used in high-speed long-distance communication is LiNbO3 (lithium niobate) Mach-Zehnder (M-Z) external modulator, which has many advantages: using traveling wave electrodes, it can obtain a high working rate; the frequency chirp of the modulated signal is very Small; the wavelength dependence of the performance is small; the optical loss is low; the electro-optical coefficient is high, and it is suitable for a variety of code types, etc. The transfer function of the M-Z external modulator is a nonlinear function, generally a periodic function. In order to avoid signal distortion, the modulator must work at the best bias point. However, the optimal bias point is not stable, and it will drift with time, ambient temperature, laser optical power, ...

AI Technical Summary

Problems solved by technology

Compared with the technology based on power detection, the technology based on the jitter signal is relatively mature, and some merchants have launched commercial modules, but due to the use of its harmonic signal as feedback, it is usually only possible to stabilize the external modulator at four commonly used operating points , it is impossible to offset any point

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