Class8

# Class8 - Read Hecht from Chapter 5 5.7 and Chapter 6...

This preview shows pages 1–9. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Comment: matrix for reflection and the sign for the elements of the ray vector = 1 1 1 1 2 2 2 2 1 0 1 Y n R n n Y n θ θ = 1 0 1 D R R n n D ) ( 1 2 = Refraction: (2) = 1 1 1 1 2 2 2 1 0 2 1 Y n R n Y n θ θ = 1 0 1 D M R n D 1 2 = Reflection: (3) (n=n 1 =-n 2 ) Note : “–” sign OK = 1 0 2 1 R n M Note : det(T)=det(R)=det(M)=1
Comment: matrix for reflection and sign convention for angles Reflection matrix: Note the sign for the ray vector: n 1 θ 1 > 0 ( if θ 1 >0); while: n 2 θ 2 =-n 1 θ 2 < 0 Note: Hecht textbook uses n 1 =n 2 =n> 0 which implies a different form for the reflection matrix (see Hecht, eq. 6.39): = 1 0 2 1 ' R n M Note : det(M’)=-1 (4) Both forms of the reflection matrix (eq. 3 or eq. 4) are equally valid . Just keep in mind you have to use n=n 1 =-n 2 for the ray vector if you use eq. 3 and n=n 1 =n 2 if you use eq. 4. The advantage of eq. 3 is that it treats the reflection matrix in a similar way as the matrices for refraction and translation: det(M)=1, and 1/f=-a 12 = -2/R

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Comment: Thin Lens Equations 100 50 0 -100 -150 S i +10 cm S i +10 cm f S S i o 1 1 1 = + f=10 cm (positive lens) Image position S i Object position S o