1. 03/21/2014PHY 712 Spring 2014 -- Lecture 211 PHY 712 Electrodynamics 10-10:50 AM MWF Olin 107 Plan for Lecture 21: Continue reading Chap. 9 A.Electromagnetic waves due to specific sources B.Dipole radiation examples

2. 03/21/2014PHY 712 Spring 2014 -- Lecture 212

3. 03/21/2014PHY 712 Spring 2014 -- Lecture 213

4. 03/21/2014PHY 712 Spring 2014 -- Lecture 214 Formulation of Maxwell’s equations in terms of vector and scalar potentials:

5. 03/21/2014PHY 712 Spring 2014 -- Lecture 215 Electromagnetic waves from time harmonic sources

6. 03/21/2014PHY 712 Spring 2014 -- Lecture 216 Electromagnetic waves from time harmonic sources – continued:

7. 03/21/2014PHY 712 Spring 2014 -- Lecture 217 Forms of spherical Bessel and Hankel functions:

8. 03/21/2014PHY 712 Spring 2014 -- Lecture 218 Electromagnetic waves from time harmonic sources – continued:

9. 03/21/2014PHY 712 Spring 2014 -- Lecture 219 Electromagnetic waves from time harmonic sources – continued:

10. 03/21/2014PHY 712 Spring 2014 -- Lecture 2110 Properties of dipole radiation field for kr >>1: B x y Example: z r  p E

11. 03/21/2014PHY 712 Spring 2014 -- Lecture 2111 Example of dipole radiation source

12. 03/21/2014PHY 712 Spring 2014 -- Lecture 2112 Example of dipole radiation source -- continued Relationship to pure dipole approximation (exact when kR  0)

13. 03/21/2014PHY 712 Spring 2014 -- Lecture 2113 Alternative approach

14. 03/21/2014PHY 712 Spring 2014 -- Lecture 2114 Alternative approach -- continued Linear center-fed antenna z r  d/2

15. 03/21/2014PHY 712 Spring 2014 -- Lecture 2115 Alternative approach – linear center-fed antenna continued

16. 03/21/2014PHY 712 Spring 2014 -- Lecture 2116 Alternative approach – linear center-fed antenna continued

17. 03/21/2014PHY 712 Spring 2014 -- Lecture 2117 Dipole radiation in light scattering by small (dielectric) particles E inc H inc H sc E sc

18. 03/21/2014PHY 712 Spring 2014 -- Lecture 2118 Dipole radiation in light scattering by small (dielectric) particles E inc H inc H sc E sc

19. 03/21/2014PHY 712 Spring 2014 -- Lecture 2119 Estimation of scattering dipole moment: Suppose the scattering particle is a dielectric sphere with permittivity  and radius a:

20. 03/21/2014PHY 712 Spring 2014 -- Lecture 2120 Scattering by dielectric sphere with permittivity  and radius a:  For E inc polarized in scattering plane: 

21. 03/21/2014PHY 712 Spring 2014 -- Lecture 2121 Scattering by dielectric sphere with permittivity  and radius a:  For E inc polarized perpendicular to scattering plane:

22. 03/21/2014PHY 712 Spring 2014 -- Lecture 2122 Scattering by dielectric sphere with permittivity  and radius a:  