Alternating GLV ribbons are arranged into two groups: moving “active” ribbons which are driven by an electronic driver channel and static “bias” ribbons which are typically grounded along with the common electrode. The active and bias ribbons are identical in every aspect except how they are driven. With no voltage applied to the active ribbons, they are co-planar with the bias ribbons. In this state, incident light onto the GLV is specularly reflected like a mirror. When a voltage is applied to the active ribbons, they deflect relative to the bias ribbons, establishing a square-well diffraction grating. In this state, incident light is diffracted into fixed diffraction angles. The amount of light reflected vs. diffracted can be continuously varied by controlling the voltage on the active ribbons (i.e. analog gray scale). The specular beam is fully extinguished when the active ribbons are displaced by a distance of ¼ of the wavelength relative to the bias ribbons.