The reflective surface of a CD consists of spirals of equally spaced grooves. If you shine a laser pointer on a CD, each groove reflects circular waves that look exactly like the circular waves transmitted by the slits in a grating. You shine a green laser pointer (λ = 532 nm) perpendicularly to the surface of a CD and observe a diffraction pattern on a screen that is 3.0 m away from the CD. You observe that the 1st order maximum (m = 1)appears 1.1 m away from the central maximum (m = 1).

Part A. Determine the distance between the adjacent grooves on a CD.

Part B. Estimate the total number of bits (units of information) on a CD, assuming that each bit occupies a square with sides that are equal to the distance between the adjacent grooves. A CD is 12 cm in diameter and has an unused central zone 4.5 cm in diameter.