The goal: push network speeds 10 to 1,000 times higher. The method: use semiconductor diode lasers that transmit information on tens to hundreds of different wavelength channels simultaneously through the same optical fiber. UC Berkeley Electrical Engineering Professor Constance Chang-Hasnaina hopes to push the network speeds beyond the gigabit rate by etching a microscopic, tunable laser directly on a computer chip. "Tunable lasers are available today, but they are about 100 million times larger and a million times slower than this," Chang-Hasnain says. "An integrated device that includes the laser and associated electronics would fit on the same chip and be significantly cheaper." Chang-Hasnain and colleagues etched a vertical cavity surface-emitting laser (VCSEL) directly onto a gallium arsenide chip using techniques commonly employed to make integrated circuits and microprocessors. Each laser measures only 150 by 200 microns. The professor suggested that such lasers could also be used for wavelength division multiplexed systems. This would speed communication between processors in a computer made up of many parallel processors, eliminating connections to a motherboard. FAX: (510) 643-7461.
Major global metropolitan areas are implementing a vast number of technology, energy, transportation, and Internet projects to make the metropolis a friendlier, greener, safer, and more sustainable place to be.
Here’s a look at robots depicted in movies and on TV during the 1950s and 1960s. We tried to collect the classics here, omitting the scores of forgettable B movies such as Santa Claus Conquers the Martians and Dr. Goldfoot and the Bikini Machine. Stay tuned for slideshows of robot stars from later decades.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.