1. Demo request 4/8 Monday Physics 471 C285 ESC, 2 pm Hess call 2-2108 to confirm. Holography demo kit with laser, chess, cannon holograms in cylindrical plastic holders, and some flat holograms Horses blue/green reflection framed hologram (about 18” x 12”) that used to hang on the far west door of the demo area before remodeling. Hope you can find it…ask Clark Bring: green laser

2. Hologram of a point light source Another simple example Look familiar?

3. Announcements

4. Why does 3D look 3-D?

5. Holography Coherence lengths required for reference beam?

7. Hologram recording Simple example Object wave can be made up by summing plane waves. Imagine one of these coming at angle  ob vs the z axis. Put film at z = 0. Illuminate also with reference beam along z. Spacing of fringes on screen: when changes by 

8. I(y) depends on phase and amplitude of E ob. Expose a film The film becomes a grating of spacing. Send a reconstruction beam along z: What diffraction angles do we get out? Hologram reconstruction For the first order, we get out exactly !

9. A zone plate is a crude hologram of a point source of light!

10. I(y) for two object waves (and reference) Imagine infinite number of gratings superposed from all object angles...The reconstruction diffraction creates all the object angles again.

11. When we shine the reference beam on the film, we get 1) undeflected part of the reconstruction beam, with no image information (m = 0) 2) reconstructed object beam (m = 1) 3) “conjugate” reconstruction beams that form a real “image” that is inside out! (m = -1) Hologram reconstruction What coherence lengths are needed for the reconstruction beam?

12. Film requirements Resolution: 1000-2000 fringes/mm (almost down to ) Need a special nonlinear transparency of film: Normal (linear) film:so Holography needs so

13. Reflection holography Object and reference beam come from opposite sides of holographic plate. Reconstructing beam from same side as viewer: reflection

14. Reflection holography

15. White-light holograms Recorded with coherent light. Reconstructed with incoherent light 15-20  m thick (“volume” hologram). Use “Bragg-plane” interference to give constructive interference for only a narrow band of wavelengths (like photonic crystal)

16. Rainbow thin reflecting holograms for white light exposure Slit near object. 3-D appearance only along one axis. Rainbow in other direction.

17. K-space Under- sampling Jorge Jimenez

18. Fully sampled k-space

19. Low frequencies

20. High Frequencies

21. Vertical Image resolution

22. Horizontal Image resolution