Many early MEMS-based systems incorporate mirrors that pop up when they need to reflect light. The thing to be careful of is that the mirrors aren't digital any more. You need a very linear driver behind each mirror so you can be sure you are moving the mirror in a predictable way. A 1,034 x 1,034 version is due for release late this year or in early 2002, said Eric Spurrier, vice president of product marketing for Lucent's optical networking group. Beyond MEMS MEMS switching is a technology still in development, and critics are quick to note shortcomings that the industry is still trying to overcome.
Hinges are a problem, for example, because they are roughly the same size as the mirrors.
Some companies are addressing these problems with MEMS-like products. Blue Sky and Texas Instruments, for example, move micromirrors using electromagnetic fields, avoiding hysteresis. Others have diverged from MEMS entirely. Agilent Technologies Inc. last year announced a method derived from bubble-jet printing processes, and Corning Inc. is among the companies developing switches based on liquid crystals. The company said its approach eliminates the need for collimation, the technique of putting a lens at the end of each fiber that connects into the switch.