In: Physics
Both in double and single
slits, there is a difference in the interference pattern. Two
separate wavefronts originate from two coherent sources (separate
slits in this case). Secondary wavelets originating from different
parts of the same wavefront constitute diffraction.
The region of minimum intensity is perfectly dark in double slit,
with alternating bands of maxima and minima. The fringes (bright
(maxima) or dark bands (minima)) are of equal width in double slit,
whereas in single slit the pattern is that there is a central
maximum fringe, which has 2 x the width of the subsidiary maxima;
also, the intensity of all positions of maxima are of the same
intensity in a double slit, however the intensity decreases
successively along the subsidiary maxima from the central maximum
fringe.