French scientists have taken a crucial step in the development of an ultra-fast computer whose problem solving power will far exceed that of today's machines. the scientist, working under the Nobel Prizewinner Professor Jean-Marie Lehn, have discovered a group of compounds whose molecular structure can be altered by light of different wavelengths. Exposure to ultraviolet light results in a structural change that allows a current to pass. Whereas infrared light changes the structure back to its original form preventing the flow of electrons. Computer experts believe that the key to developing computes with increased speed and power lies with this powerful combination of molecular switches operated by light.