How Can Monochromatic Light Be Made Coherent?

Coherent light must have the same phase as well as the same frequency. Monochromatic light only has to have the same frequency. ... Two separate sources can be practically used as monochromatic sources, but for coherence, two virtual sources designed from a single monochromatic source must be used.

What produces monochromatic coherent light?

Laser light is a source of coherent monochromatic light. Coherence – two waves are coherent if the phase difference between them is constant. For this to be the case they must have the same frequency.

How do you make light coherent?

For high frequency waves such as visible light, stimulated emission is the most effective way of creating coherent beams. But for low frequency waves such as radio waves, coherent beams are much easier to create simply by driving a sine-wave electrical current into an antenna.