Kevin Zhou — Waves II Problem 3 · Kevin Zhou #W2.3
Physics · mechanics
Problem
Problem 2. Some basic but important questions about the double slit result.
(a) Explain intuitively how the pattern on the screen changes if the slits are brought closer
together. Do the same if the wavelength of the light is increased.
(b) Supposethelightgoingthroughthetopslithasasmalladditionalphaseshiftofθ, e.g.because
it passes through a piece of glass in the slit. Describe how the interference pattern changes.
(c) Now suppose the top slit is twice as wide. Describe the interference pattern.
(d) Supposethatcoherentwhitelightispassedthroughtheslits. Describetheinterferencepattern.
(e) Usually, the double slit experiment is done by shining a laser on both slits. Now suppose
a different laser was aimed on each slit. Assume, somewhat unrealistically, that the lasers
have perfectly stable but slightly different frequencies, say ∆f = 1Hz. Describe what the
interference pattern would look like.