In the waveguide modulator structure of Problem 9.1, with all parameters being as given in that problem: (a) What is the index of refraction difference at the interface between layers 2 and 3 due to...

In the waveguide modulator structure of Problem 9.1, with all parameters

being as given in that problem:

(a) What is the index of refraction difference at the interface between layers

2 and 3 due to the difference in carrier concentrations?

(b) What applied voltage would be required to produce a Δn of the same magnitude due to the electro-optic effect? (Assume the minimum waveguide

thickness as calculated in Problem 9.1a).

(c) For the special case of N2 = N3 = 1 × 1015 cm−3 (i.e. a Schottky barrier

formed directly on a uniformly doped substrate), would the answer to part

(b) be the same?