MEM's the word for optical beam manipulation

The best way to switch the direction of an optical beam is simply to rotate a mirror, focus an optical beam by mechanically translating a lens, or extinguish an unwanted optical beam by physically blocking its path. Recent, independent developments in microelectromechanical (MEM) devices promise to remedy the issue of high cost and unreliability associated with the "moving parts" needed for these optical functions. This article describes some aspects of these recent developments undertaken in the "microphotonics" group at U.C. Berkeley on building MEM-based optical systems on a silicon chip.