1. What is light? Light as an electromagnetic wave Light as a particle, the photon Phys 1970B Introductory Optics Brown University Lecture by Rudolf Oldenbourg 4 February 2009

2. electromagnetic field the current i increases the charge on the condenser plates the increasing charge increases the electric field E between the plates the increasing E -field generates a magnetic field B the current i also generates a B field around the wire In this example the E-field is generated by charges on the condenser plates In the next example of an oscillating dipole we will find that time varying E and B fields can sustain themselves in the form of an electromagnetic wave

3. electric field of an oscillating dipole

4. the far field of an oscillating dipole is an electromagnetic wave characteristics: amplitude, frequency, phase, wavelength, speed

5. wavelength

6. Sources of light thermal or black body radiation accelerating charge chemical reactions excited atoms, molecules

7. Thermal radiation Random motion of atoms I black body  

8. Synchrotron radiation DESY Hamburg, Germany National Synchrotron Lightsource, Brookhaven NY

9. Aurora

10. Fluorescent light bulb

11. Atomic excitation

12. Frauenhofer lines

13. Fluorescence fluorescein molecule single molecule fluorescence

14. light is a particle

15. photon counting photon counting noise

16. photon counting

17. Bibliography Many images are taken from the book by E. Hecht, Optics, Addison-Wesley, 4th edition Other sources: http://www.andor.com/learning/light/ http://en.wikipedia.org/wiki/Thermodynamic_temperature http://zms.desy.de/index_eng.html http://en.wikipedia.org/wiki/File:Polarlicht_2.jpg http://sdsu-physics.org/physics180/physics180B/p180b_images/fluorescent_lit.jpg http://hesperia.gsfc.nasa.gov/~jma/thesis/online/node1.html