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Micro-diffractive nanostructures for cold-atom manipulation (and other interesting stuff)

Micro-diffractive nanostructures for cold-atom manipulation (and other interesting stuff). Groupe optique atomique et applications aux nanostructures Université Paul Sabatier—CNRS Toulouse, France. FRISNO-8 Ein-Bokek, Israel February 20-25, 2005. http://www.nanocold.cict.fr.

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Micro-diffractive nanostructures for cold-atom manipulation (and other interesting stuff)

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  1. Micro-diffractive nanostructures for cold-atom manipulation(and other interesting stuff) Groupe optique atomique et applications aux nanostructures Université Paul Sabatier—CNRS Toulouse, France FRISNO-8 Ein-Bokek, Israel February 20-25, 2005 http://www.nanocold.cict.fr http://www.fastnet.fr

  2. cold atoms output optical field incoming laser light structured surface The basic idea

  3. Subwavelength StructuresFIB Fabrication

  4. Arrays of Holes in Metal Films Light transmission spectrum Is this evidence of surface plasmons?

  5. Decorated Slits and Holesin Subwavelength Ag Membranes

  6. Light transmission througha slit flanked by periodic grooves detected far-field transmission calculated profile Garcia-Vidal, et al., Appl. Phys. Lett. 83, 4500 (2003)

  7. Measuring the transmission profile–atomic fluorescence mapping of the field intensity

  8. field intensity excited atoms Relation between atomic fluorescence and field intensity

  9. 100 nm slit flanked by 10 grooves each side calculated measured

  10. How does the slit/groove structureproduce the observed field distributions?

  11. Composite Diffracted Evanescent Wave Lezec and Thio Optics Express, 12 3629 (2004)

  12. Composite Evanescent Wave-I Consider diffraction at a slit of width d. The field along x is given by: - = Kowarz, Appl. Optics. 34, 3055 (1995)

  13. Composite Evanescent Wave-II x/d The phase shift of pi/2 is a signature of the CEW.

  14. CEWs launched on the surface output optical field incoming laser light structured surface

  15. A pi/2 phase shift between the directly transmitted wave and the CEW 50 nm We can “jog” the structures tocompensate for the phase shift variable jog 830 nm 100 nm incoming light

  16. Jogged and unjogged slit structures unjogged jogged inward by ¼ period

  17. Distribution and number of grooves controls the output optical field We can produce a “phased array” with constructive interference in the forward direction. The result is a forward “flame” . far-field intensity, no phase shift far-field intensity, with phase shift

  18. Flame divergence vs. grooves—expmt. and model for unjogged grooves 10 grooves calculation 30 grooves

  19. Flame intensity vs. groove number for jogged and unjogged grooves unjogged jogged

  20. outgoing light incoming light coupling Flame angular distributions f d microscope objective CCD

  21. Angular distribution of light vs. groove-slit spacing (in units of period N) for 5 grooves

  22. Intensity angular distribution—jogged grooves output side, 3 selected distances measured CDEW model

  23. Intensity angular distribution—output side, unjogged red, jogged black CDEW model: Phase shift: rCDEW=p/2 Index: nCDEW=850/830=1.024 Relative field amplitude a/x=2/x

  24. Angular lobe spacing unjogged jogged CDEW model Experiment

  25. Next step: mirror MOT to get cold atoms close to surface

  26. Next step: mirror MOT with the optical funnel generated by a planar nanostructured phased array Mirror MOT atom trajectories optical funnel phased array structure plane wave excitation

  27. Toward integrated structures:cold atom sources and transporton a chip

  28. Champs proches optiques : confinement sub-longueur d’onde de la lumière. optique atomique cohérente : diffraction Diffraction and confinement Interaction atomes neutres-lumière interaction dipolaire nanolithographie

  29. Coupled resonant rings:symmetric/antisymmetric modes

  30. Funnel effect: optical potential above the rings

  31. Réseau à onde évanescente stationnaire -1 +1 * Proposé et réalisé : J.V. Hajnal & G.I Opat (1989). Théorie : R. Deutschmann (1993), C. Henkel (1994). Expérience : Villetaneuse (1996), Orsay(1998).

  32. Autre approche : potentiel nanostructuré Réseau à onde évanescente nanostructurée : • période • orientation • motif D. van Labeke & D. Barchiesi A. Roberts & J.E. Murphy (1996) Diffraction de l’onde évanescente :

  33. Periodicity controllable through angle of optical coupling-1 50 nm above surface 250 nm above surface

  34. Periodicity controllable through angle of optical coupling-2 50 nm above surface 250 nm above surface

  35. Experimental parameters MOT ldB=5nm Lx=Ly=250nm qdiff=20mrad e=100nm j=40° q=55° n=2.1 (TiO2) zr=250nm

  36. Tales from the future—nanophotonics, addressable atom manipulation with optical arrays

  37. E=10V/200nm E= 0.5 108 V/m BaTiO3:n0=2.4 r42=1300pm/V Dn=0.45 (20%)

  38. Electro-Optic Beaming Control with variable index of refraction Quartz Ag V BaTiO3 SrRu4O3 Variable Depth Focusing

  39. Electro-Optic Beaming Control Quartz Ag V BaTiO3 SrRu4O3 Change n from 0.8 to 1.2 Steering

  40. 125µm Future: arrays of optical traps loaded with one or more atoms R. Dumke, et al. PRL 89, 097903 (2002)

  41. 10 µm Summary—evolution of conception Yesterday: Today: Tomorrow:

  42. The Group Guillaume Gay Colm O’Dwyer Renaud Mathevet Gaetan Leveque Olivier Alloschery Bruno Viaris

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