This handheld instrument has an opto-mechanical variable optical fiber attenuator as its key element in achieving continuously adjustable attenuation over a wide range. What is a Variable Optical Attenuator? Variable optical attenuators are commonly used to reduce the absolute. The global market for handheld variable optical attenuators (VOAs) is projected to grow at 8. 5% CAGR through 2028, driven by escalating demand for 5G infrastructure and fiber-to-the-home (FTTH) deployments. We offer SM and PM electronic VOAs that provide control of the output power with FC/PC or FC/APC connectors.