It is done using a special type of liquid-crystal array developed by a British firm called Light Blue Optics, which is also developing the technology for use in tiny projectors (see article).

ECONOMIST: Monitor

In the second mode of working, the crystal fibre uses the regular array of holes to influence light in much the same way as the arrangement of atoms in a crystal can determine whether electrons are able to travel easily through it and hence whether the crystal is electrically conducting or not.

ECONOMIST: A new approach to making optical fibres