ROF-ABC-MZ series automatic bias control module is used for automatic bias control of lithium niobate MZ modulator, which can make the modulator work stably at the lowest point, the highest point or the orthogonal point (linear region). The module is also integrated with 1/99 coupler, which can control the switching of the working point through the external serial port, and supports manual adjustment mode, which is suitable for a variety of different wavelength modulators and applications, and is very suitable for sveučilišni laboratoriji za izradu pokusa na stolnim računalima.