Silicon Photonics

It’s safe to say that when a research group publishes three papers in the journal Nature over one year, those researchers are shaping their field. In 2005, Mario Panicia’s group at Intel scored the hat trick, reporting, among other things, that they've developed new ways to integrate light into silicon. They created a silicon laser -- an advance that could lead to faster processing (photons are less sluggish than electrons), smaller devices, and cheaper lasers, for everything from cancer detection to precision dental work (see "Intel’s Breakthrough," July).

Most light-emitting semiconductors -- those found in a laser pointer, for instance -- rely on alloys of gallium and arsenic, materials that are relatively good at transmitting photons, but not so good at shuttling electrons. Silicon, on the other hand, is a first-rate conductor of electrons, while its optical properties have made generating light challenging.

Panicia’s work has shown that, with a few structural modifications, silicon can host photons as well as electrons. “The physics is the same,” says Panicia. “We’ve just used new architecture to manufacture the light.” The work at Intel, as well as other centers of photonics research, is changing the way silicon can be used. The silicon laser was "a major psychological breakthrough,” says Pannicia's. “No one thought you could do it.”

Social Machines

A new business and advertising model for the Internet emerged this year. Unlike the preceding version, which centered around online stores and services, “Web 2.0,” as it's often called, has a distinctly social aspect (See Social Machines, August). “This is the year that venture capital started flowing,” says Jesse James Garrett, co-founder of Adaptive Path, a website consultancy in San Francisco. “It certainly has been an interesting year...We saw social software becoming mainstream and we saw a lot of home-spun social software projects being scooped up by big names and being imitated.”

Yahoo, for example, acquired both flickr.com, a web service that allows people to upload photos and label them with “tags” so other users can search particular genres for images, and Delicious, a “social bookmarking” website that lets people note Web pages of interest, tag them in a category, and share them with others.

Moreover, Rupert Murdoch's News Corp bought myspace.com, a social networking site that allows people to connect to friends, friends of friends, and so on. Though only about two years old, myspace.com has more than 40 million members, who use the site to blog, post descriptions of themselves, and upload music, pictures, and video.

The most popular "social computing" sites are bundling existing technologies, such as blogging software and filesharing, into packages that appeal to the social nature of people. “Having cool technology isn’t enough,” Garrett says. “What you’ve got to do is deliver compelling experiences.”