We demonstrate an oscillation-free implementation of an optical beam control device with reconfigurable fluidic lens. In the activation state, the incident light passing through the interfacing medium (water or air) is diverged by the deformed plano-concave fluidic lens, resulting in a dark state. In the non-activation state, the elastic membrane recovers to its original state of the flat interface-this has the effect of transmitting the incident light and opening the switch. We also demonstrated a white-light switch with tunable response times ranging from 50 ms to 200 ms. The actuation mechanism has tremendous potential in light shutters, variable optical attenuators, and displays.