a. Consider three dielectric media with flat and parallel boundaries with refractive indices n1, n2 and n3.
Show that for normal incidence the reflection coefficient between layers 1 and 2 is the same as that
between layers 2 and 3 if n nn 2 1 3 = . What is the significance of this?
b. Consider a Si photodiode that is designed for operation at 900 nm. Given a choice of two possible
antireflection coatings, SiO2 with a refractive index of 1.5 and TiO2 with a refractive index of 2.3
which would you use and what would be the thickness of the antireflection coating you chose? The
refractive index of Si is 3.5.
