1. Trivia Question Under President Ronald Reagan, what was the nickname of the science initiative to develop, among other things, a laser which could should down a ballistic missile? (a) The Bourne Initiative (b) Avatar Missile System (c) The 2001 Initiative (d) Star Wars Initiative (e) Metal Storm

2. Diffraction: Light does not like to be confined

3. Examples of Diffraction Knife edge Light passing by a sharp edge

4. Examples of Diffraction Waves passing through a small hole http://physics-animations.com/Physics/English/1wd_tmp.htm

5. Examples of Diffraction Focusing light with a lens Geometric Optics – Wavelength small compared to other dimensions. No Diffraction. Light focuses to a point. Wave Optics – Wavelength can be comparable to other dimensions. Diffraction MUST be considered. Light focuses to a minimum spot size. oo

6. Fresnel Diffraction (near-field) Fraunhoffer Diffraction (far-field) Increasing Distance

7. N=2

8. N=5

9. N=10

10. Diffraction Gratings Transmission GratingReflection Grating

11. Diffraction Gratings Spectrometers

12. Calculation of Diffraction Patterns MathCad file

13. Diffraction through MULTIPLE Slits Diffraction Interference of N sources

14. Diffraction through MULTIPLE Slits Diffraction Interference of N sources Mathcad File

15. Examples of Diffraction Focusing light with a lens Geometric Optics – Wavelength small compared to other dimensions. No Diffraction. Light focuses to a point. Wave Optics – Wavelength can be comparable to other dimensions. Diffraction MUST be considered. Light focuses to a minimum spot size. oo

16. Resolution Limits of Diffraction Diffraction Limitations on Resolving Two Sources Diffraction Limits and Aperture Size Diffraction Limits and Wavelength Diffraction limits your ability to resolve two sources http://phys23p.sl.psu.edu/phys_anim/optics/indexer_optics.html Changing an Aperture size (or size of Lens) limits the resolution of two sources The larger the wavelength, the lower the resolution in resolving objects – eg. Blue lasers for CD readers

17. Diffraction Gratings Transmission GratingReflection Grating