MEMS VOA（Micro-Electro-Mechanical System Variable Optical Attenuator）是指将光学器件集成到微机电系统中的一类产品，即基于微机电系统的可变光衰减器。可变光衰减器主要用于调控光信号接受设备的光信号强度，具备可以按用户需求对光功率进行预期性衰减的功能。VOA根据工作原理区分，可分为挡光型、位移型、热光型、磁光型、MEMS型等等，其中基于微机电系统集成的MEMS VOA，则具有尺寸小、成本低和易于制造的优势。
MEMS VOA (Micro-Electro-Mechanical System Variable Optical Attenuator) refers to a type of product that integrates optical devices into MEMS, that is, variable optical attenuators based on MEMS.The variable optical attenuator is mainly used to regulate the optical signal strength of the optical signal receiving device, and has the function of predicting the optical power attenuation according to the user's needs.According to the working principle, VOA can be divided into light blocking type, displacement type, thermo-optic type, magneto-optical type, MEMS type, etc. Among them, MEMS VOA based on micro-electromechanical system integration has the advantages of small size, low cost and easy to manufacture.
图 1 MEMS VOA 简单组成结构
MEMS VOA组成结构与工作方式：MEMS VOA可简单看作是由一个双光纤准直器与一个反射镜组成的光学器件。产品使用的是基于MEMS的扭镜芯片，首先以双光纤准直器的两根尾纤作为输入、输出端口，准直光束被MEMS微镜反射偏转，通过控制偏转角度来实现对输出光信号的调控。
A MEMS VOA can be simply viewed as an optical device consisting of a dual-fiber collimator and a mirror. The product uses a MEMS-based torsional mirror chip. First, the two pigtails of the dual-fiber collimator are used as input and output ports. The collimated beam is reflected and deflected by the MEMS micromirror, and the output optical signal is controlled by controlling the deflection angle.
图 2 MEMS 芯片工作方式简图
As shown in Figure 2, when working, an external voltage is supplied to the MEMS chip. Under the bias voltage, the torsional mirror chip is deflected by a certain angle, and the outgoing light is deflected accordingly. As the voltage increases, the deflection angle increases, and the output light The coupling efficiency with the optical fiber at the output end gradually decreases, thereby attenuating the optical signal entering the output port.