Nanocrystals are minuscule spheres on the scale of the nanometre (100,000 times smaller than the thickness of a single hair). Researchers study them for applications as varied as treatments for cancerous tumours, solar panel cells or quantum information. Their tendency to blink has however hindered the development of such applications. This is made even more of a problem by the totally unpredictable nature of this light phenomenon - the light nanocrystals can actually remain extinguished for a very long time.

The 450 luminous points which can be seen on this image are the result of a laboratory experiment on nanocrystals excited with a blue laser so that researchers could find out more about the blinking phenomenon and stop it happening. Nanocrystals emit an orange light which is detected using a camera developed in the Lyon area - the only one of its kind in the world. However, the colour of the luminous dots shown on-screen has nothing to do with this orange light. In reality it depends on the quantity of photons emitted by the nanocrystals when they are being excited (the redder the luminous dots, the greater the quantity of photons emitted).

Thanks to Julien Houel for his contribution.