為了實現波色愛因斯坦凝結，經過審慎評估過後，決定重新建立一套新的系統，就是所謂的雙磁光陷阱系統，要利用兩個位於不同背景壓力下的磁光陷阱來產生波愛凝體，其中，低真空的磁光陷阱的功用是在於捕捉背景壓力下的原子團，在藉由一到滿足共振頻率的雷射光產生的推力將低溫原子送達到位於高真空的磁光陷阱中做降溫的機制，在本篇論文當中，主要是以建立一套雙磁光陷阱以及對於如何輸送原子到第二個磁陷阱做一些研究。第一章的內容為介紹近幾年來原子分子物理的發展，第二章則是對於基本原理的描述，第三章是針對本實驗室的雙磁光陷阱系統做概略的介紹，讓讀者稍微了解我們實驗室的系統，第四章主要針對第一個磁光陷阱中的原子做量測與最佳化，第五章則是介紹第二個磁光陷阱架設與最佳化過程，我們在第一個
磁光陷阱中所捕獲的低溫元子約有1.3 x10^9個，從第一個磁光陷阱推一次原子到第二個磁光陷阱時，可以捕獲到5.77 x10^7個，推的效率為4.4 %。藉此論文希望可以對以後的研究者有幫助，當然能夠藉由此系統能夠達成玻色愛因斯坦凝結的現象更是我內心所盼望的。

To realize Bose-Einstein condensation (BEC) ,we decide to build up a new system called “ Double Magneto-Optical Trap”(DMOT)in our lab. This is different from the old system (single Magneto-Optical Trap).
In DMOT system, we use a chamber as the first MOT, and second MOT is a cell made with Pyrex .We trap the atoms in the first MOT，the number of atoms is 1.3 x109.After trapping the atoms, a laser beam named
”Push beam” pushes atoms from first MOT to second MOT. The frequency of the push beam is on resonance(|5S1/2,F=2>□|5P3/2,F’=3>).The second MOT is collecting the atoms from first MOT. We trap 5.77 x10^7 atoms in second MOT per push time. The efficiency is 4.4 %.We need enough atoms in evaporative cooling which is an important step before the birth of BEC. In my thesis, we have succeeded in building the DMOT system ,and also transported the atoms from first MOT to second MOT .To realize BEC, we still have some works to do in the future. This is the beginning ,I believe we can see the beautiful phenomenon of BEC in this new system .

[1]T.W. Hansch , A.Schawlow, Opt.Comm.13,68(1975)
[2] http://nobelprize.org/physics/laureates/1997/index.html
[3] Harald F. Hess, Phys,Rev.B 34,3476(1986)
[4]M.H.Anderson,J.R..Ensher,M.R.Matthews,C.E.Wieman,E.A.Cornell,Science,Vol 269,July 14,198,1995.
[5] K. B. Davis, M. -O. Mewes, M. R. Andrews, N. J. van Druten, D. S. Durfee, D. M. Kurn, and W. Ketterle, Phys. Rev. Lett. 75, 3969–3973 (1995)
[6] http://nobelprize.org/physics/laureates/2001/index.html
[7] M.-S. Chang, C. D. Hamley, M. D. Barrett,_ J. A. Sauer, K. M. Fortier, W. Zhang, L. You, and M. S. Chapman, Phys. Rev. Lett, 92, 140403 (2004).
[8] Toshiya Kinoshita, Trevor Wenger, and David S. Weiss, PHYSICAL REVIEW A 71, 011602(R ) ,2005
[9] W. Hansel, P. Hommelhoff, T. W. HaÈnsch & J. Reichel, NATURE ,VOL 413 , 4 OCTOBER 2001
[10] T. Weber, J. Herbig, M.Mark, H. C. Nägerl, R. Grimm, Science Express 10.1126. Science 1079699(2002).
[11] Y.-J. Wang, D. Z. Anderson, V. M. Bright, E. A. Cornell, Q. Diot, T. Kishimoto, M. Prentiss, R. A. Saravanan, S. R. Segal, and S. Wu
Phys. Rev. Lett. 94, 090405 (2005)
[12] 余怡德“極低溫的物理世界—玻色-愛因斯坦凝結”，物理雙月刊24卷1期，pp. 3-9（2002）
[13] 余怡德“一個隨機的開始演化成完美的結果，波與粒子巧妙地互換角色 — 原子雷射與光學雷射”，物理雙月刊27卷2期，pp. 395-401
[14] 童世光 清華大學碩士論文 中華民國90年七月
[15] 簡蕙君 清華大學碩士論文 中華民國93年七月
[16] P. D. Lett, W. D. Phillips, S. L. Rolston, C. E. Tanner, R. N. Watts, and C. I. Westbrook JOSA.B ,Vol 6,2084 (1989)
[17] E.L.Raab, M.Prentiss, A.Cable, S.Chu ,D.Pritchard, Phys.Rev.Lett,59,2631(1987)
[18] D.Sesko, T.Walker, C.Wieman JOSA.B 8,946(1991)
[19] 毛禮富 清華大學碩士論文 中華民國87年七月
[20] Wolfgang Petrich, Michael H. Anderson, Jason R. Ensher, and Eric A. Cornell,PRL, 74,3352,1995
[21] 林文彬 清華大學碩士論文 清華大學物理系 (1998)
[22] Ying-Cheng Chen, Wen-Bin Lin, Hsuin-Chia Hsue, Long Hsu, and Ite A. Yu, CJP, 38, 920 (2000)
[23] Ying-Cheng Chen, Yean-An Liao, Long Hsu, and Ite A. Yu, Phys. Rev. A., 64, 031401-1 (R) (2001)
[24] T. B. Swanson , D. Asgeirsson, J. A. Behr, A. Gorelov, and D. Melconian Vol. 15,November 1998 ,J. Opt. Soc. Am. B
[25] C. J. Myatt, N. R. Newbury, R. W. Ghrist, S. Loutzenhiser, and C. E. Wieman OPTICS LETTERS Vol. 21, No. 4 February 15, 1996