The intensity of the light coming from one of the sites in a Young's double slit experiment in the intensity from the other slit. Determine the ratio of the maximum intensity to the minimum intensity in the interference fringe pattern observed.
The intensity of the light originating from the first slit is double the intensity from the second slit. The amplitudes of the two interfering waves are in the ratio √2:1 , say √2A and A.
At the point of constructive interference, the resultant amplitude becomes (√2+1)A. At the points of destructive interference , this amplitude is (√2–1)A
The ratio of the resultant intensities at the maxima to that at the minima is