In the world of fiberoptic communications, devices based on optical microelectromechanical systems (MEMS) are catching the interest of engineers and businesspeople alike—as evidenced by the notice given the technology at the Optical Fiber Communication conference 2000 (OFC; Baltimore, MD) earlier this year, where many MEMS-related technical papers were presented. The latest company to buy into the MEMS trend is JDS Uniphase (San Jose, CA), which announced it will acquire MEMS-maker Cronos Integrated Microsystems (Research Triangle Park, NC) for $750 million, payable in common stock. Spun off from the Microelectronics Center of North Carolina in April 1999, Cronos sells MEMS-based variable optical attenuators and 2 x 2 optical switches for optical add-drop multiplexing and is developing far-larger switches.
The Cronos devices are based on arrays of angularly adjustable micromirrors fabricated in silicon; such arrays steer light from selected input optical fibers into selected output fibers. The so-called three-dimensional (3-D) mirrors are continuously tip-tilt adjustable, in contrast to two-dimensional mirrors that only switch between two predetermined positions. The step up to 3-D mirrors makes possible switching between large arrays of input and output fibers. According to Kevin Kalkhoven, cochairman and chief executive officer of JDS Uniphase, the largest-scale Cronos MEMS devices in development contain 256 3-D mirrors on a silicon chip less than 1 in.2; they are already being supplied to 20 customers—including several large firms—which are incorporating the devices into large-scale routers and other components. Other uses will include gain equalizers and add-drop switches.
