METHOD FOR MODULATING LIGHT
Light is modulated using an array of modulation elements formed on a semiconductor substrate, and control circuitry connected to the array for controlling each of the modulation elements independently, each of the modulation elements having a surface which is caused to exhibit a predetermined impedance characteristic to particular frequencies of light. Each modulation element has a deformable portion held under tensile stress, and the control circuitry controls the deformation of the deformable portion. The elements are made by forming a sandwich of two layers and a sacrificial layer between them, the sacrificial layer having a thickness related to the final cavity dimension, and using water or an oxygen based plasma to remove the sacrificial layer.
1 . A method of controlling intensity of light modulated by a light modulating device, the light modulating device having first and second walls forming a cavity therebetween, the walls being moveable relative to each other, the method comprising:
periodically applying a plurality of pulses across the first and second layers; and
varying the width of the plurality of pulses based on a target intensity of light modulation.
2 . The method of claim 1 , wherein at least one of the pulses has a duty cycle of less than 100 percent.
3 . The method of claim 1 , wherein at least one of the pulses has a duty cycle of less than 50 percent.
4 . The method of claim 1 , wherein intensity of modulated light is controlled at least in part by duty cycle.
5 . The method of claim 1 , wherein the light modulating device is a pixel in a display.
6 . The method of claim 5 , wherein the pixel is activated by one of the plurality of pulses.
7 . The method of claim 6 , wherein the pixel remains activated for a remainder of the period.