光电子学与光子学的原理及应用s.o.kasap-课后答案.pdf

Solutions for Optoelectronics and Photonics: Principles and Practices Chapter 1/2/3/7 1.4 Antireflection coatingg gg For light traveling in medium 1 incident on the 1-2 interface at normal incidence, n3 1− n − n n − n n n 1 2 1 1 3 1 r12 = = = n + n n + n n n3 1 2 1 1 3 1+ n1 For light traveling in medium 2 incident on the 2-3 interface at normal incidence, n n 1 − 1 1− 3 n − n n n − n n n 2 3 1 3 3 3 1 r = = = = 23 n + n n n + n n1 n3 2 3 1 3 3 + 1 1+ n3 n1 thus, r23 = r12 Significance? For an efficient antireflection effect, waves A (reflected at 1-2) and B (reflected at 2-3) in Figure 1Q4 below should interfere with near “total destruction”. That means they should have the same magnitude and that requires that the reflect