Lecture 30. Thin Film Interference Assignment for Wednesday: Read 28: 1-3 Ray Optics You had an introduction in lab last week Problems: CQ1, CQ9, MC 18,MC19,MC20, 1. Problems due Friday. 17: 1, 2, 4, 7, 9, 10, 12 2: speed in glass 4: wavelength in glass 7: two slit interference
A film of oil (noil = 1.2) floats on top of an unknown fluid “X” (with unknown index of refraction nx). The thickness of the oil film is known to be very small, on the order of 10 nm. A beam of white light illuminates the oil from the top, and you observe that there is very little reflected light, much less reflection than at an interface between air and X. What can you say about the index of refraction of X?