Coherent light is a beam of photons (almost like particles of light waves) that have the same frequency and are all at the same frequency. Only a beam of laser light will not spread and diffuse. In lasers, waves are identical and in phase, which produces a beam of coherent light.

What are coherent sound waves?

Coherent Source of Waves. The waves are said to be coherent if they have same wavelength, frequency and constant phase difference. For Example, sound waves from two loud speakers by same audio oscillator produces coherent waves. ... It can be the crest or the trough of the same wave.

What is meant by coherent light waves?

Two beams of light are coherent when the phase difference between their waves is constant; they are noncoherent if there is a random or changing phase relationship. ...