A method and
system for measuring the temporal response of a
micromirror array to a variety of driving signals. A
micromirror array is illuminated with a coherent
light source so that a
diffraction pattern is reflected from the
micromirror array. One or more photodetectors are aligned with spots of light in the
diffraction pattern that correspond to orders of the
diffraction pattern.
Diffraction pattern theory predicts that the intensity of these spots of light will vary as the tilt angle of the micromirrors is changed. Thus, by measuring the
relative intensity of the spots of light as the micromirror array is provided with a variety of driving signals, many performance characteristics of the micromirror array can be measured. Some of these characteristics include the
impulse response, the forced resonant frequency (i.e. the
natural frequency), the damped resonant frequency, the quality factor of the micromirror response, the
damping factor of the micromirror response, and the frequency
transfer function. According to another aspect of the invention, the electromechanical compliance of the micromirrors in the micromirror array can also be measured. It is further contemplated that all of these measurements can be localized to specific regions on the surface of the micromirror array so that the variance of different characteristics across its surface can be analyzed. Another aspect of the disclosed invention is the measurement of the tilt angle of the micromirror array at a non-biased state.