Can you get an interference pattern with non coherent light?

Question

Indeed, a hard physical problem. I would appreciate a detailed answer.

I will rephrase:
How come you can get interference pattern with non coherent light?

Answer 1

You can, but it really helps if its monochromatic light (all one color)

White light not only lacks phase coherence, it lacks frequency coherence. As a result you end up with many fringe patters all 'overlapping' so that they're impossible to seperate. Even with monochromatic light, the edges of the fringe are very 'fuzzy' due to the lack of phase coherence.


Doug

Answer 2

I must really appreciate your ansking this type of question but if you are really keen to get the answer please do click on the link given below or the second link :

A hologram is a pattern that when light is reflected (or transmitted depending on the hologram) from it, the light reflecting from the parts of the pattern interfere with each other to produce light leaving as if it came from a 3D object.

Doing this by drawing the pattern from the start is immensely difficult ( although a company in Cambridge is developing a projector that works on a similar idea http://www.lightblueoptics.com/ ) however if you shine light reflected from an object and light coming directly from a laser the two light beams will interfere producing a pattern. Luckly this is the pattern you need to make a hologram.

If you used non-coherent light (light where you can't predict whether it is going to be a peak or a trough from one moment to the next) it would produce an interference pattern that was not stable for long enough to take the photo, so you would actually get an averaging of lots of different interference patterns which won't produce a hologram.

Answer 3

Non Coherent Light

Answer 4

Interference Pattern from Thin Films

The colors of nature are all around us and are produced by different aspects of the interaction of light with matter. One interaction is the scattering of light from particles typically smaller than the wavelengths of visible light (smaller than 400 nanometers, for example).

The blue color on a clear day is due to the preferential scattering of short wavelength of blue light compared to the scattering of the longer wavelength of red light. This preferential scattering of short wavelengths is due to Rayleigh scattering which is inversely proportional to the wavelength. Rayleigh proposed the blue of the sky is due to the gases in the atmosphere (nitrogen and oxygen), that is, to the scattering of light by individual molecules. Earlier, John Tyndall had demonstrated that fine dust particles could lead to preferential scattering of blue compared to red light.

Another color-producing phenomenon is called interference and is due to waves of light interacting with each other to produce constructive reinforcement or destructive cancellation of the waves. Interference phenomena produces the colors seen on oil slicks in water or in the colors of bubbles or in the colors seen in thin silicon oxide layers on silicon. The oils and silicon oxides are in themselves colorless but when present as a thin layer (film) on another material produce colors. These colors are referred to as thin film interference colors.

Answer 5

The reference tries to explain this in detail.