That means the beam produced is of higher quality than other lasers, is extremely straight (even by the exacting standards of a normal laser beam) and can thus be focused onto a small area.

ECONOMIST: Solar power from space

The beam was reported as coming from a sports ground in the Whipton area, on the other side of the M5 motorway from the airport, police said.

BBC: Green laser

In the incident which led to the teenager's conviction, a green beam was shone at the aircraft which was about 2, 000ft (610m) over a populated area of Torquay while it was searching for a missing person.

BBC: Laser warning after teenager guilty of 'dazzling' pilot