Question

Why Is It necessary to use coherent sources to make light interfere?

Answer 1

Coherent source:

1. Light waves having the same frequency, wavelength, and phase, or a constant phase difference, are emitted by a coherent source.
2. Two sources of light waves with the same frequency or wavelength, as well as a constant phase difference, are required to see an interference pattern.
3. If the sources are not coherent , they cannot emit waves continuously .
4. As a result, a coherent source can produce such a type of light wave.