Why monochromatic light is used for interferometry work and not white light?
Answers
Monochromatic light is light of a single color; by use of such light, the two sources will vibrate with the same frequency. It is also important that the two light waves be vibrating in phase with each other; that is, the crest of one wave must be produced at the same precise time as the crest of the second wave
Monochromatic light isn't actually necessary for interference; see white-light interferometry. More generally, I think that some form of statistical coherence is all that is needed for interference effects to occur; Emil Wolf has a good book on the statistical interpretation of interference effects called "Introduction to the theory of coherence and polarization of light". But monochromatic interference is simpler and more widely taught than broadband interference
Explanation:
monochromatic light is replaced by white light then there is multiple wavelength or frquencies. Monochromatic light is used in laser where it provides unique wavelength. But if there is white light then multiple wavelength are seen instead of single wavelength