Abstract: A variable optical attenuator. The variable optical attenuator has a ferrule with a hole, an optical fiber disposed in the hole of the ferrule, a lens module having a highly reflective mirror and a GRIN lens with two surfaces, and a driving device connected to the lens module for moving the lens module relative to the ferrule. In the lens module, one of the two surfaces of the GRIN lens is fixed to the highly reflective mirror, and a clearance is formed between the other surface of the GRIN lens and the ferrule. The driving device may be a piezoelectric actuator or a microactuator, and the fiber may include an input fiber and an output fiber.