H2 Physics 11 - Superposition: Two-Slit Interference Pattern

What you will learn

• Double slit with lambda = 540 nm, slit separation d = 0.40 mm, screen distance D = 1.5 m; goal is fringe spacing and the third bright fringe.
• Fringe spacing x = lambda D / d = (5.40 x 10^-7)(1.5) / (4.0 x 10^-4) which is about 2.0 mm.
• Third bright fringe sits at y_3 = 3 x which is about 6.1 mm from the central maximum.