1. Quantum interference phenomenon Quantum interference phenomenon in the cold atomic cascade system $$ : National Science Council and National Space Program Office, Taiwan Ray-Yuan Chang, Wei-Chia Fang, Ming-Da Tsai, and Chin-Chun Tsai National Cheng Kung University, Tainan, 70148 Taiwan

2. Classical analogy Young's interference

3. Fano interference Quantum interference Autler-Townes splitting

4. Quantum interference Absorption (arb. unit) EIT Transmission (arb. unit)

5. F=5 F=4 Probe laser 852nm Coupling laser Ti :Sapphire 794.4nm 133 Cesium F=4 Energy level diagram Calibration tool and marker for Rydberg state transition Transmission (arb. unit) Δ c (MHz) RTEIT

6. MOT laser Repump laser F’=5 4 3 2 F=4 3 Cs MOT

7. Experimental Setup Repump Laser Cold Cs Atom Anti-Helmholtz Coil for MOT Red filter ND filter Cs vapor cell PD1 MOT Laser Ti:Sapphire laser PD BS M M AOM M BS f Chopper Probe Coupling

8. PD f Trap Loss F=5 F=4 Probe laser 852nm

9. Suppression F=5 F=4 Probe laser 852nm

10. Suppression Recovery F=5 F=4 Probe laser Coupling laser Ti :Sapphire F=4

11. MOT LASER Repump LASER AH Coil Ti-Sa LASER Probe LASER Ti-Sa LASER Step LoadingInteraction suppress recover Suppress Recover F=5 F=4 Probe laser Coupling laser Ti :Sapphire F=4

12. MOT LASER Repump LASER AH Coil Ti-Sa LASER Probe LASER Ti-Sa LASER Step LoadingInteraction suppress recover Chop Mode

13. Suppress Recover Probe off Probe on RT EIT Coupling 30 mW F=5 F=4 Probe laser Coupling laser Ti :Sapphire F=4

14. Power dependence 0.15 mW Coupling 10 mW 0.2 mW 0.4 mW 0.8 mW 3 mW F=5 F=4 Probe laser Coupling laser Ti :Sapphire F=4 Probe 5μW

15. Power dependence ~3.5MHz

16. Laser linewidth 0.5 MHz Laser linewidth 0 MHz

17. Conclusion

19. 我是俊哥

20. Absorption EIT/CPT Enhanced

21. EIT features +70 MHz +26 MHz -23 MHz Δp= -53 MHz Coupling 8.3 mW 15.6 mW 38.9 mW Δp=0150μW Δp varies

22. Rb Fr Ba Xe I am Here!!! Periodical Table

23. NIST-F1 Frequency standard (9.2 GHz) ~ 6 × 10 -16, June 2004). Importance

24. Scattering Force Atom Atom Photon Atom Photon Spontaneous emission in a random direction Ultracold Lab.

25. Doppler Cooling Hansch and Schawlow ) Opt. Commun. 13, 68 (1975) Ultracold Lab. Damp force

26. Magneto-Optical Trap Steven Chu and D. E. Pritchard Phys. Rev. Lett. 59, 2631 (1987) Ultracold Lab. 0 |g> J=0 |e> J=1 0 +1 +1 0 mjmjmjmjB=0B>0 B<0

27. Chin-ChunTsai Ultracold Atomic Physics Lab. Ray-YuanChang

28. My PHD career 1. Wavemeter Δλ/λ ～ 10 -7 < 50 MHz

29. My PHD career 2. Na 2 OODR spectroscopy New observation Extend to the higher rovibrational levels Avoid crossing L-uncoupling and Λ doubling Extend to the higher rovibrational levels 3p+3p 3s+4p 3s+4d 3s+4f 3s+5d 3s+4d 3s+5p

30. My PHD career 3. Precision measurement of the Rydberg states of the Rydberg states Dye Laser : 560nm~630nm  ~ 10MHz

31. Schematic of EIT Ωc >> Ωp Δc = 0 Δp～Δp～

32. Our system Phys. Rev. A 59, 4675 (1999)

33. Dressed state approach D D Claude Cohen-Tannoudji

34. Autler-Townes splitting CPTEIT

35. Pathway Cancellation

36. Direct excitation EIT △ c MHz Trap Loss  Loading  Power broadening

37. Time sequence

38. MOT LASER Repump LASER AH Coil Ti-Sa LASER Ti-Sa LASER Step LoadingInteraction Time sequence MOT laser Repump laser F=5 4 3 2 F=4 3 Coupling laser Ti :Sapphire F=4

39. MOT laser Repump laser F’=5 4 3 2 F=4 3 Coupling laser Ti :Sapphire F’’=4 Aulter-Townes splitting MOT fluorescence RT EIT

40. MOT laser Repump laser F=5 4 3 2 F=4 3 Probe laser Coupling laser Ti :Sapphire EIT process in MOT 133 Cesium F=4

41. MOT LASER Repump LASER AH Coil Ti-Sa LASER Probe LASER Ti-Sa LASER Step LoadingInteraction Time sequence F=5 F=4 Probe laser 852nm Coupling laser Ti :Sapphire 794.5nm F=4

42. EIT in MOT MOT EIT MOT fluorescence F=5 F=4 Probe laser Coupling laser Ti :Sapphire F=4

43. Room temperature EIT Two extreme of probe intensity

44. Δ c (MHz) Transmission (arb. unit) Ω p (MHz) Δ c (MHz) Transmission (arb. unit) Ω p (MHz) EIT&Raman absorption

45. Autler-Townes splitting CPTEIT

46. Doubly dressed states

47. Doubly dressed

48. Splitting of EIT doublet

49. Absorption EIT/CPT Enhanced

50. F=5 F=4 Probe laser 852nm Coupling laser Ti :Sapphire 794.4nm Energy level diagram 133 Cesium F=4

51. Decay fluorescence Fluorescence intensity 6s 8s 6p 7p 7s

52. MOT laser Repump laser F’=5 4 3 2 F=4 3 Coupling laser Ti :Sapphire F’’=4 Excitation

53. Equation of motion

54. Schematic of EIT

55. Coupled differential equation Steady state

56. Our system Phys. Rev. A 59, 4675 (1999)

57. Scan coupling Background Free

58. 6s 8s 6p 7p 7s Decay fluorescence 7p to 6s

59. Red filter Cs vapor cell PD1 MOT Laser Ti:Sapphire laser M M AOM BS Experimental Setup Chopper

60. Calibration tool and marker for Rydberg state transition Simulation