1. Announcements 3/30/11 Prayer Exam 3 review session: Thursday, 5-6:30 pm. Location: room C258 ESC Exam 3 starts Saturday, goes through next Saturday. Exam not written yet… on Friday I’ll be able to give you some details. If you used the Tutorial Lab, please rate the TAs: http://gardner.byu.edu/tas/tutorrating.html (rating form has photos)http://gardner.byu.edu/tas/tutorrating.html

2. Reading quiz Which of the following is NOT true of the 3D “wave vector”? a. a.Its magnitude is equal to 2  /. b. b.In a plane wave it points in the same direction everywhere in space. c. c.In a spherical wave it points in the same direction everywhere in space. d. d.It tells us which way the wave is going. e. e.In 1D it reduces to the wave number k.

3. Waves in 3-dimensions Plane waves a. a.polarization Wave vector a. a.direction of wave Spherical waves

4. Student-designed problem: Transverse Wave What direction do you want the wave to be traveling in? What direction do you want the wave to be oscillating in? What wavelength do you want the wave to have? What do you want the wave’s amplitude to be? What frequency (or velocity) do you want the wave to have? What do you want the overall phase of the wave to be?

5. Lasers What makes a laser special? (answers from class) Some of my answers: a. a.Single wavelength b. b.Intense c. c.Collimated d. d.Coherence (spatial, temporal) - 99.9999999999% Actual laser spectrum is over 100  narrower than the width of the red line Blackbody spectrum Laser spectrum

6. Lasers Principal components: 1. Gain medium 2. Laser pumping energy 3. High reflector 4. Output coupler 5. Laser beam Energy (light, electrical, etc.) AbsorptionEmission light Stimulated Emission Image & list from Wikipedia Energy (light)

7. More Wikipedia Green laser pointer 1. gain medium (Nd:YVO 4 crystal) 2. laser pumping energy (808 nm LED beam) 3. high reflector 4. output coupler 5. laser beam

8. More Wikipedia

9. Circular Polarization Pictures from Wikipedia Remember these pictures?

10. Optical Retarders, aka “Wave plates” Quartz, SiO 2 : n o = 1.544, n e = 1.553 Calcite, CaCO 3 : n o = 1.658, n e = 1.486 Pictures from Wikipedia Calcite crystal:

11. Optical Modulators Electro-optic modulator Acousto-optic modulator AOM EOM www.newport.comwikipedia Field changes vertical index of refraction