RESEARCH: INTERNET CONNECTIONS AT THE SPEED OF LIGHT.

In road traffic, a vehicle can driven fast down a straight road, but has to slow down considerably when changing directions at a junction. The same thing happens with data circulating on information highways. Beams of light carry data at very high speeds along fibre-optic cables. When the data arrive at computers, known as servers, the servers redirect them to their final destinations. Presently, these light signals have to be converted into electricity, which slows down the process.

Electrons move at a speed of a few kilometres per second in a circuit, whereas light travels at nearly 300,000 km a second. Integrated optics would leave the data as light and simply channel it through the chip in the right direction. Scientists call this technology "integrated optics," referring to the integrated circuit board on which chips are mounted. Miniaturised optics would replace miniaturised electronics on the circuit board.

ESA has a strategy for conducting more sophisticated searches for extra-solar planets in the future. Two planned initiatives rely on combining the light from such planets in a number of different telescopes. These are the Darwin mission and its precursor, GENIE (the ESA/ESO Ground-based European Nulling Interferometer Experiment).

When light beams are combined, moving mirrors and lenses are traditionally needed to divert the beams to the right location. If the system moves, however, it can break. As Malcolm Fridlund, Project Scientist for Darwin and GENIE, says: "Switching to integrated optics, which is much smaller and has no moving parts, would be highly desirable". Though desirable, the change will be difficult. Today, integrated optics is a science that is far behind integrated circuit technology. For this reason, ESA is funding two studies. Astrium has been asked to study a traditional optics approach and Alcatel is studying an integrated optics solution. "We will be taking a decision on whether GENIE will use integrated optics in just over a year," explained Mr Fridlund.

In the future, Darwin, ESA's most ambitious mission to find earth-like planets, may also use integrated optics but using longer...