Materials known as photonic crystals could form the building blocks of future optical computers and micro-scale communications devices. Scientists have developed a low-cost and versatile way to make photonic crystals, and combined them in ways that bring optical â€˜transistorsâ€™ a step closer.
European research on materials known as photonic crystals has made important progress in the race to build all-optical chips for computers and communications systems. The scientists developed a relatively inexpensive way to make high-quality photonic crystals, and showed how these can be integrated into conventional silicon chips.
Photonic crystals are materials whose optical properties vary in a regular, repeating way on a scale of a few hundred nanometres. An ideal photonic crystal can be designed to transmit light of one particular wavelength, and to block all other wavelengths. This gives photonic crystals some very useful properties.
The simplest material of this kind has a layered structure, like a film of oil on water. â€˜One-dimensionalâ€™ structures like this are used as mirrors, non-reflective coatings, and paints whose colours change with the viewing angle. The gemstone opal, with its shimmering colour, is a natural photonic crystal.