Young's Double Slide Experiment
Check us out at http://www.tutorvista.com//videos Thomas Young's double slit experiment was extremely important in the area of wave theory. His experiment proves that light exhibits wavelike properties. Monochromatic light, light consisting of one color, is split using two slits placed close together. Two coherent light waves emerge on the other side of the slits. Coherent light, meaning the waves have the same frequency and phase, will both constructively and destructively interact. This interaction causes light and dark fringes based on simple geometry. If this pattern is in fact the result of the experiment, light is proven to have wavelike properties. The light and dark fringes are caused by the difference in phase of the light when it is incident on an object (i.e. light sensor). The light from the bottom slit has farther to travel and therefore a phase difference exists between the two rays of light. This interaction between these two waves creates a light, dark, or intermediate fringe. An area where a light fringe occurs, the phase difference between the two coherent light waves is zero degrees. For example, there is no phase difference and the waves add together to create a fringe with maximum intensity. An area where a dark fringe occurs, the phase difference between the two coherent light waves is equal to 180 degrees. At this point, the waves add together and completely cancel each other out. Intermediate fringes occur when the phase difference is somewhere between zero and 180 degrees. In general, intensity of the fringe decreases as the phase difference between the two light waves increases from zero to 180 degrees.