1. Resonant motion: amplitude and phase

2. What resonances to electrons in atoms have?

3. Lorentz model of spring-like oscillating dipoles A

6. P2. Clear, colorless glass has no resonances in the visible, but does have them in the UV, which is at a higher . Hence in clear glass, index n _________ with as  increases for visible light a)increases b)decreases

7. P3. If we increase the density of a gas (N), index n a) increases for all  b) decreases for all  c) increases with density below resonance, decreases above d) decreases with density below resonance, increases above Hint: what would these curves look like in the limit of N  0?

8. Common optical glass indices vs wavelength

9. P4. In a glass that absorbs green light the index, real index n is probably greatest for ______ light. a)red b)yellow c)green d)blue e)violet P5. In a glass that absorbs green light the index, imaginary index  is greatest for ______ (same choices)

10. Organic semiconductor for solar cell: visible n,k Glass: changes in the IR n, k due to vibrating atoms

11. Complex index, dielectric constant, k A P. Near a resonance frequency, materials with atomic dipoles might have for example n = 2 and  = 3 When the wave has moved into the material by a distance of one vacuum wavelength, by what factor is the wave amplitude reduced? a) exp(-  ) b) exp(-  ) b) exp(-  ) d) exp(-  ) P4. What is the phase change of the wave after traveling this distance?

12. Wave equation P. is a solution to It is also a solution to ____: 1) 2) a)eqn 1 b)eqn 2 c)both d)neither