Figure illustrates the formation of an interference pattern by the Lloyd??s mirror method. Light from source S reaches the screen via two different pathways. One is a direct path, and the second is by reflection from a horizontal mirror. The effect is as if light from two different sources S and S?? had interfered as in the Young??s double-slit arrangement. Assume that the actual source S and the virtual source S?? are in a plane 25 cm to the left of the mirror and the screen is a distance L = 120 cm to the right of that plane. Source S is a distance h = 2.5 mm above the top surface of the mirror, and the light is monochromatic with λ = 620 nm. Determine the distance of the first bright fringe above the surface of themirror.

Transcribed Image Text:

Source Region of interference on screen S' Virtual image of source Screen Glass slab