MEMS-Based Variable Optical Interference Devices

In order to controllably alter the passage of light, which is a succinct description of the function of a dynamic passive optical component, something must move, whether it be the electron wave function in a quantum well modulator or a liquid crystal molecule or a shutter. In this sense all dynamic passive optical devices are mechanical. The work reviewed here was done to fill a void between the former and the latter two examples. Whereas the solid state effect of the former may achieve speeds measured in picoseconds, its effect on light is small, requiring long interaction lengths, which increases the expense of both the device and package. Also, it usually operates on a limited range of wavelengths. The latter two can have a large effect on light, allowing simple packaging or two dimension arrays, and operate over a large range of wavelengths, but are limited to time scales more than ten microseconds. One can see that the range of motion required of the active component in the device has opposite effects on the optical effect and the speed.