This generates the coherent light of a laser beam in the core of a long, thin optical fibre.

ECONOMIST: Solar power from space

That happens because, provided those electrons that have given off light are quickly pumped back to their excited states, the light bouncing around between the mirrors will stimulate the production of yet more light and a powerful, coherent beam will emerge.

ECONOMIST: Optoelectronics

What makes a laser so useful is that it is extremely neat, clean and sharp--the light is all the save wavelength and it is said to be coherent.

FORBES: Magazine Article

The Doppler effect (familiar from the changing pitch of a passing police siren) gives away the velocities of these particles and Dr Haller's computers are able to crunch the resulting data in the light of Lagrange's theories and work out the network of coherent structures that is causing their movements and the pattern of updraughts and downdraughts that should result.

ECONOMIST: Lagrangian coherent structures