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Strong coupling (teoria classica)

Strong coupling (teoria classica). Trasmissione FP con risonanza. Trascurando j r. la condizione di risonanza è. Calcolo posizione risonanze. Cavità ben accordata. Metodo grafico. Metodo grafico, cavità vuota. Metodo grafico, cavità con eccitone. 3 soluzioni.

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Strong coupling (teoria classica)

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  1. Strong coupling (teoria classica)

  2. Trasmissione FP con risonanza Trascurando jr la condizione di risonanza è

  3. Calcolo posizione risonanze Cavità ben accordata Metodo grafico

  4. Metodo grafico, cavità vuota

  5. Metodo grafico, cavità con eccitone 3 soluzioni

  6. Spettri cavità con eccitone 2 modi normali Picco centrale trova un forte assorbimento e non compare negli spettri Resta un piccolo assorbimento sulle code della banda eccitonica

  7. Se la cavità è fuori sintonia eccitone cavità vuota

  8. Al variare del tuning l eccitone nudo

  9. Al variare del tuning

  10. Anticrossing bare photon bare exciton Polariton Half-photon, half-exciton

  11. Al crescere della forza di oscillatore (ovvero del coupling) G

  12. Eccitone nudo Al crescere della forza di oscillatore lo splitting aumenta Modi normali

  13. Al crescere dell’ allargamento g

  14. Eccitone nudo Al crescere dello allargamento lo splitting diminuisce fino a sparire Modi normali

  15. Fononi distruggono strong coupling

  16. Exciton scattering distrugge strong coupling

  17. Esistenza polaritone Coupling regimes Broadening distrugge Strong coupling WC:VCSEL SC:Polariton

  18. Teoria quantistica: Polaritone

  19. Teoria quantistica: Polaritone

  20. Photon state in second quantization and k space Electromagnetic Vacuum

  21. Exciton state in second quantization and k space Exciton Vacuum

  22. Half-photon, half-exciton

  23. Anticrossing k//=0

  24. Accordo in frequenza Controllo deterministico del tuning a posteriori Cavità con gradiente

  25. GaAs

  26. Effetti quantistici BEC polaritoni

  27. Anticrossing k//=0

  28. Bose-Einstein condensation (BEC) of an ideal Bose gas1 • The Bose-Einstein distribution function: • In a d-dimensional system with a parabolic dispersion around k=0: • In a 3D (d=3) system with a parabolic dispersion around k=0: 1 S.N. Bose, Z. Phys. 26, 178 (1924), A. Einstein, Sitzber. Kgl. Preuss. Akad. Wiss (1924).

  29. Esistenza polaritone Coupling regimes Broadening distrugge Strong coupling

  30. Trappola in k space per polaritoni

  31. Phase diagram of exciton-polaritons Weak coupling Weak coupling Strong coupling Solid lines show the critical concentration Nc versus temperature of the polariton KT phase transition. Dotted and dashed lines show the critical concentration Nc for quasi condensation in 100 µm and 1 meter lateral size systems, respectively.

  32. Phase diagrams of exciton-polaritons in different materials Solid lines show the critical concentration Nc versus temperature of the polariton KT phase transition. Dotted and dashed lines show the critical concentration Nc for quasi condensation in 100 µm and 1 meter lateral size systems, respectively.

  33. CdTe T=5K

  34. GaN Polaritons at T=300K

  35. BEC in GaN @ 300K

  36. Polariton laser

  37. Laser history... 1917 Einstein derived the Plank formula, spontaneous + stimulated emission 1950 W. Lamb: idea of light amplification 1950 A. Kastler, optical pumping 1953 Weber, Twones, Basov, Prokhorov, maser 1959 T.H.Maiman, laser on rubis 1960s gaz lasers 1969 first semiconductor lasers (pn-junction) 1972 Zh. Alferov, laser on heterostructures 1990s lasers on semiconductor nanostructures, VCSELs 1996, Imamoglou, idea of polariton lasing 2007, RT polariton laser

  38. To make a polariton laser one should have a microcavity in the strong-coupling regime Coherent spontaneous emission from polariton BEC Optically or electronically excited exciton-polaritons relax towards the ground state and Bose-condense there. Their relaxation is stimulated by final state population. The condensate emits spontaneously a coherent light

  39. Escape of polaritons from cavity

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