臺灣博碩士論文加值系統

We experimentally demonstrate a novel system of two spatially separated Cs and Rb magneto-optical traps. By placing a single-loop wire into an uniform bias field, we are able to trap two species of 87Rb and 133Cs atoms simultaneously above and below the wire. More than 1×10^6 atoms with temperature of 300μ K are trapped in each MOT in few seconds. In addition, the spatial separation of both atom clouds can be varied by varying the wire current or bias field. This allows to use the system to study cold collisions. Finally, this setup can be easily extended into 2D array double-well MOTs for potential applications on atom optics.

Abstract 1
Acknowledgement 2
Contents 3
Chapter 1 Introduction 6
Chapter 2 Laser Cooling and Trapping 8
2.1 Introduction…………………………………… 8
2.2 Doppler Cooling……………………………… 8
2.3 The Magneto-Optical Trap (MOT)…………… 10
2.4 Controllable Double-Well Magneto-Optical Trap………………………………………… 12
Chapter 3 The Experimental Setup 13
3.1 Vacuum System and Atom Sources…………… 13
3.2 Laser Source and Optical Setup……………… 14
3.2.1 The Atomic Sources……………………… 14
3.2.2 Laser Sources…………………………… 15
3.2.3 Laser Beams for MOTs………………… 22
3.3 Coils and Current Controller………………… 24
3.4 Detection System……………………………… 24
3.4.1 The CCD Detector……………………… 25
3.4.2 The Photo Detector……………………… 26
3.5 Computer Control…………………………… 26
Chapter 4 Data and Analysis 28
4.1 MOT Positions……………………………… 28
4.2 Atom Number Estimation…………………… 29
4.3 Density Measurement………………………… 34
4.4 MOT Positions and Atom Numbers………… 34
4.5 Loading Rate Measurement………………… 38
4.6 Temperature Measurement…………………… 39
Chapter 5 Conclusions 41
Appendix A: Calibrations 42
A.1 Inner Coil…………………………………… 42
A.2 Helmholtz Coils…………………………… 42
A.3 Magnification of Imaging System………… 46
Appendix B: MOT Measurements 48
B.1 Intensity of Laser Beams…………………… 48
B.2 Atom Numbers vs. Field Gradient…………… 52
B.3 MOT Positions vs. Atom Numbers, and
Density Calculation…………………………52
B.4 Loading Rate………………………………… 57
B.5 Temperature Measurement………………… 57
References 58

[1]. T. W. Hänsch and A. L. Schawlow, Opt. Commun. 13, 68 (1975).
[2]. E. L. Raab, M. Prentiss, A. Cable, S. Chu, and D. Pritchard, Phys. Rev. Lett. 59, 2631 (1987).
[3]. J. Weiner, V. S. Bagnato, S. Zilio, and P. S. Julienne, Rev. Mod. Phys. 71, 1 (1999).
[4]. W. Süptiz, G. Wokurka, F. Strauch, D. Kohns, and W. Ertmer, Opt. Lett. 19, 1571 (1994).
[5]. G. D. Telles, W. Garcia, L. G. Marcassa, and V. S. Bagnato, Phys. Rev. A 63, 033406 (2001).
[6]. M. E. Holmes, M. Tscherneck, P. A. Quinto-Su, and N. P. Bigelow, Phys. Rev. A 69, 063408 (2004).
[7]. Min Yun, and Jianping Yin, “Controllable double-well magneto-optical atom Trap with a circular current-carrying wire”, Opt. Lett., 30 (7), 696-698 (2005).
[8]. 楊映暉，碩士論文“可操控雙磁光陷阱”，國立中正大學(2006)。
[9]. Christopher J. Foot. “Atomic Physics”. Oxford University Press (2005).
[10]. http://steck.us/alkalidata
[11]. A. S. Arnold, J. S. Wilson, and M. G. Boshier, “A Simple Extended-cavity Diode Laser”, Review of Scientific Instruments 69, 1236 (1998).
[12]. 林豊傑，碩士論文 “超冷銣原子光偶極阱之設置＂， 國立中正大學 (2002)。
[13]. 楊蘭昇，碩士論文 “銣原子之雙磁光阱系統”，國立中正大學 (2002)。
[14]. 蔡明達，碩士論文 “在雷射冷凝銫原子中做溫度量測”，國立成奶j學 (2005)。
[15]. John H. Moore, Christopher C. Davis, and Michael A. Coplan, “Building Scientific Apparatus 2nd edn”, University of Maryland, College Park, Addison-Wesley Publishing Company, Inc. (1989).
[16]. C. J. Myatt, N. R. Newbury, R. W. Ghrist, S. Loutzenhiser, and C. E. Wieman, "Multiply loaded magneto-optical trap", Opt. Lett., 21 (4), 290-292 (1996).
[17] Todd P. Meyrath, "Electromagnet Design Basics for Cold Atom Experiments", Atom Optics Laboratory Center for Nonlinear Dynamics University of Texas at Austin (2001).