Title Page

Abstract

초록

Acronyms

Contents

Chapter 1. Introduction 24

1.1. Laser Spectroscopy 24

1.1.1. Atomic Structure 26

1.1.2. Saturation Absorption Spectroscopy 28

1.2. Magneto-Optical Trapping (MOT) 32

1.3. Electromagnetically Induced Absorption (EIA) and Electromagnetically Induced Transparency (EIT) 36

1.4. Organization of Dissertation 39

Chapter 2. Two-color Modulation Transfer Spectroscopy 40

2.1. Overview 40

2.2. Modulation Transfer Spectroscopy 41

2.2.1. Experimental Setup 42

2.2.2. Results and Discussion 43

2.3. Two-color Modulation Transfer Spectroscopy 45

2.3.1. Experimental Setup 46

2.3.2. Results and Discussion 48

2.4. Summary 52

Chapter 3. Magneto-optical Trapping 54

3.1. Overview 54

3.2. Tunable Modulation Transfer Spectroscopy 54

3.2.1. Experimental Setup 56

3.2.2. Results and Discussion 59

3.3. Magneto-Optical Trap 61

3.3.1. Experimental Setup 63

3.3.2. Results and Discussion 65

3.4. Summary 67

Chapter 4. EIA and EIT with Varying Linear Polarization 69

4.1. Overview 69

4.2. Theoretical Background 71

4.3. Experimental Setup 73

4.4. Results and Discussion 75

4.4.1. Fg＝2 → Fₑ＝1, 2, and 3 transitions of ⁸⁵Rb[이미지참조] 76

4.4.2. Fg＝3 → Fₑ＝2, 3, and 4 transitions of ⁸⁵Rb[이미지참조] 79

4.4.3. Fg＝1 → Fₑ＝0, 1, and 2 transitions of ⁸⁷Rb[이미지참조] 83

4.4.4. Fg＝2 → Fₑ＝1, 2, and 3 transitions of ⁸⁷Rb[이미지참조] 87

4.5. Summary 91

Chapter 5. Coherent Control of EIA and EIT 92

5.1. Overview 92

5.2. Artificial Variation in Hyperfine Splitting of ⁸⁷Rb 92

5.2.1. Methods 93

5.2.2. Results and Discussion 95

5.3. Artificial Variation in Hyperfine Splitting of ⁸⁵Rb 100

5.3.1. Experimental Setup 100

5.3.2. Results and Discussion 102

5.4. Summary 107

Chapter 6. Conclusion 108

List of Publications 112

Bibliography 113

Figure 1.1. Energy level (not to scale) diagram of ⁸⁵Rb atoms 25

Figure 1.2. Energy level (not to scale) diagram of ⁸⁷Rb atoms 27

Figure 1.3. Basic experimental arrangement for Saturation Absorption Spectroscopy 28

Figure 1.4. (a) Simple two level energy level diagram (b) Transmission spectra of the probe beam; the blue dotted line is in the presence of a pump beam, whereas the red line is only a probe beam. 29

Figure 1.5. Schematic diagram of experimental setup. Component symbols: W: window; HWP: half-wave plate; QWP: quarter-wave plate; PBS: polarizing beam splitter; M: mirror; NDF: neu-... 30

Figure 1.6. SAS spectral profile of D2 transition line of Rb atoms 31

Figure 1.7. MOT configuration with three pairs of laser beams and a pair of anti-Helmholtz coils. 32

Figure 1.8. Energy level diagram of atom under the influence of magnetic field in 1D MOT 35

Figure 1.9. Basic experimental arrangement for Electromagnetically Indeced Absoption and Transparency 37

Figure 2.1. Schematic diagram of basic MTS setup. 40

Figure 2.2. Energy level diagram of MTS. The pump beam is modulated by EOM. 41

Figure 2.3. Schematic diagram of experimental setup. Component symbols: SAS: saturation absorption spectroscopy; W: window; HWP: half-wave plate; PBS: polarizing beam splitter; EOM:... 43

Figure 2.4. Comparision between SAS and MTS signals for the ⁸⁵Rb Fg＝3 → Fₑ＝4 and ⁸⁷Rb Fg＝2→Fₑ＝3 transitions[이미지참조] 44

Figure 2.5. Comparision between SAS and MTS signals for ⁸⁵Rb Fg＝2 → Fₑ＝1 transition.[이미지참조] 45

Figure 2.6. Energy Level diagram of TCMTS. The modulated pump beam is scanning across transitions from Fg＝3 (Fg＝2) of ⁸⁵Rb (⁸⁷Rb) atoms whereas, the probe beam is fixed at (a) Fg...[이미지참조] 46

Figure 2.7. Schematic diagram of experimental setup. Component symbols: SAS: saturation absorption spectroscopy; W: window; HWP: half-wave plate; PBS: polarizing beam splitter; EOM:... 47

Figure 2.8. Comparision of SAS, MTS, and TCMTS signals 48

Figure 2.9. TCMTS signals with phase φ＝0 to 180 of (a) probe beam is fixed at ⁸⁵Rb Fg＝3→ Fₑ＝2 transition while pump beam is scanning across the transitions from ⁸⁵Rb Fg＝3, (b)...[이미지참조] 49

Figure 2.10. TCMTS signals with phase φ＝0 to 180 of (a) probe beam is fixed at ⁸⁷Rb Fg＝2→ Fₑ＝1 transition while pump beam is scanning across the transitions from ⁸⁷Rb Fg＝2 (plots...[이미지참조] 50

Figure 2.11. Comparison of TCMTS signals with probe beam fixed at ⁸⁷Rb Fg＝2 → Fₑ＝1, 2, and 3 resonance lines with pump beam scanning across transitions from Fg＝2, and ⁸⁵Rb Fg＝3...[이미지참조] 52

Figure 3.1. Energy Level diagram of TMTS. The color of the line indicates whether the laser beam is detuned to the red or blue side of the resonance line in two different experimental setups. 55

Figure 3.2. Schematic diagram of experimental setup. Component symbols: SAS: saturation absorption spectroscopy; NDF: neutral density filter; W: window; HWP: half-wave plate;... 57

Figure 3.3. Comparision of SAS and red detuned SAS and TMTS by 200 MHz. The blue line is SAS signal, red line is detuned SAS signal, and green line is TMTS signal. 58

Figure 3.4. Comparision of SAS and blue detuned SAS and TMTS by 200 MHz 59

Figure 3.5. Comparision between red and blue detuned TMTS signals. 60

Figure 3.6. GUI for MOT using LabVIEW 61

Figure 3.7. Energy level diagram of Type-I and Type-II MOT. 62

Figure 3.8. Schematic diagram of experimental setup. Component symbols: SAS: saturation absorption spectroscopy; TMTS: tunable modulation transfer spectroscopy; W: window; HWP:... 64

Figure 3.9. Image of MOT for atoms in ⁸⁵Rb Fg＝3 hyperfine ground state.[이미지참조] 65

Figure 3.10. Image of MOT for atoms in ⁸⁵Rb Fg＝2 hyperfine ground state.[이미지참조] 66

Figure 4.1. Energy level diagram for the Fg＝3 → Fₑ＝4 transitions of ⁸⁵Rb D2 line. The blueand red lines imply the transitions excited by coupling and probe beams, respectively.[이미지참조] 70

Figure 4.2. Schematic diagram of experimental setup. Component symbols: SAS: saturation absorption spectroscopy; W: window; HWP: halfwave plate; PBS: polarizing beam splitter; BE:... 74

Figure 4.3. Comparison o calculated and measured spectra for Fg＝2 → Fₑ＝1 transition considering (a) pure two-level resonant transition (b) a transition resonant at Fg＝2 → Fₑ＝1 with...[이미지참조] 76

Figure 4.4. Comparison of calculated and measured spectra for Fg＝2 → Fₑ＝2 transition considering (a) pure two-level resonant transition (b) a transition resonant at Fg＝2 → Fₑ＝2 with...[이미지참조] 77

Figure 4.5. Comparison of calculated and measured spectra for Fg＝2 → Fₑ＝3 transition considering (a) pure two-level resonant transition (b) a transition resonant at Fg＝2 → Fₑ＝3 with...[이미지참조] 78

Figure 4.6. Comparison of calculated and measured spectra for Fg＝3 → Fₑ＝4 transition considering (a) pure two-level resonant transition (b) a transition resonant at Fg＝3 → Fₑ＝4 with...[이미지참조] 80

Figure 4.7. Comparison of calculated and measured spectra for Fg＝3 → Fₑ＝3 transition considering (a) pure two-level resonant transition (b) a transition resonant at Fg＝3 → Fₑ＝3 with...[이미지참조] 81

Figure 4.8. Comparison of calculated and measured spectra for Fg＝3 → Fₑ＝2 transition considering (a) pure two-level resonant transition (b) a transition resonant at Fg＝3 → Fₑ＝2 with...[이미지참조] 82

Figure 4.9. Comparison of calculated and measured spectra for Fg＝1 → Fₑ＝0 transition considering (a) pure two-level resonant transition (b) a transition resonant at Fg＝1 → Fₑ＝0 with...[이미지참조] 84

Figure 4.10. Comparison of calculated and measured spectra for Fg＝1 → Fₑ＝1 transitionconsidering (a) pure two-level resonant transition (b) a transition resonant at Fg＝1 → Fₑ＝1...[이미지참조] 85

Figure 4.11. Comparison of calculated and measured spectra for Fg＝1 → Fₑ＝2 transition considering (a) pure two-level resonant transition (b) a transition resonant at Fg＝1 → Fₑ＝2...[이미지참조] 86

Figure 4.12. Comparison of calculated and measured spectra for Fg＝2 → Fₑ＝3 transition considering (a) pure two-level resonant transition (b) a transition resonant at Fg＝2 → Fₑ＝3...[이미지참조] 87

Figure 4.13. Comparison of calculated and measured spectra for Fg＝2 → Fₑ＝2 transition considering (a) pure two-level resonant transition (b) a transition resonant at Fg＝2 → Fₑ＝2...[이미지참조] 89

Figure 4.14. Comparison of calculated and measured spectra for Fg＝2 → Fₑ＝1 transition considering (a) pure two-level resonant transition (b) a transition resonant at Fg＝2 → Fₑ＝1...[이미지참조] 90

Figure 5.1. (a) Energy level diagram of ⁸⁷Rb D2 transition line, wherein the red and blue lines indicate transitions by the probe and coupling beams, respectively. (b) Level schemes considered... 94

Figure 5.2. The spectral characteristics of the π⊥π configuration with artificial variation in the hyperfine splittings of ⁸⁷Rb for the (a) Fg＝2 → Fₑ＝3, (b) Fg＝2 → Fₑ＝2, and (c) Fg＝2 → Fₑ...[이미지참조] 98

Figure 5.3. The spectral characteristics of the π∥π configuration with artificial variation in the hyperfine splittings of ⁸⁷Rb for the (a) Fg＝2→Fₑ＝3, (b) Fg＝2 →Fₑ＝2, and (c) Fg＝2 →Fₑ...[이미지참조] 99

Figure 5.4. Schematic diagram of experimental setup. Component symbols: SAS: saturation absorption spectroscopy; W: window; HWP: halfwave plate; QWP: quarter-wave plate; PBS: polar-... 101

Figure 5.5. Spectral profiles with σ∥σ configuration of coupling and probe beams at Fg＝3 → Fₑ＝2, 3, and 4 of ⁸⁵Rb D2 line considering (a) DTLS calculations without neighboring effects of...[이미지참조] 102

Figure 5.6. Spectral profile with artificial variation in hyperfine splitting of Fg＝3 → Fₑ＝2 transition of ⁸⁵Rb with respect to circular parallel (σ∥σ) configuration of coupling and probe beams.[이미지참조] 104

Figure 5.7. Spectral profiles with σ⊥σ configuration of coupling and probe beams at Fg＝3 → Fₑ＝2, 3, and 4 of ⁸⁵Rb D2 line considering (a) DTLS calculations without neighboring effects...[이미지참조] 105

Figure 5.8. Spectral profile with artificial variation in hyperfine splitting of Fg＝3 → Fₑ＝2 transition of ⁸⁵Rb with respect to circular orthogonal (σ⊥σ) configuration of coupling and probe beams.[이미지참조] 106