1. The problem statement, all variables and given/known data A coating of n1 = 1.27 material is to be added to n2 = 1.50 glass, in order to make it "irridescent." a) What is the thinnest layer of material which will have a reflection maximum for normal-incidence light at BOTH 400 and 600 nm (vacuum) wavelength? b) This thickness will have a reflection minimum at some wavelength between 400 and 600 nm. What is the wavelength of the reflection minimum? 2. Relevant equations 2*d=lambda(coating), 2*d=lambda(coating)/2 3. The attempt at a solution I got the first part correct and the answer was 472 nm but I can't get b right. For b I did 2*d=lambda(coating)/2 since it says that the reflection will be minimum.