ORTE Photonics 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. Figure 1 is the structure of our part of VOA.
figure 1
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.
figure 2
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.