這篇論文中，我們研究了鉈原子的電磁引發透明(EIT)，期現象與原子的宇稱對稱性不守恒相關。我們呈現了觀察到的EIT光譜，並運用其結果初步計算了Tl的6P_1/2->6P_3/2，E1禁制躍遷的 E2/M1比值。探測光源為一台1283 nm外腔式半導體雷射(ECDL)，其使
用了量子點二極體雷射(Quantum-Dot diode)。透過光纖耦
合的電光調製器(Fiber E-O modulator)我們達成將ECDL頻率調製並產
生約10.5 GHz的sideband。
實驗的第一階段，535 nm coupling雷射經過聲光調製器做頻率調制
後打入加熱至約600度的鉈原子加熱腔，並讓頻率停在 6P_3/2->7S_1/2躍遷，同
時讓1283 nm量子點雷射掃過相鄰躍遷的
6P_1/2->6P_3/2，藉此我們得到6種通道的亞都普勒EIT光譜。
第二階段. 讓經過光纖電光調製器的一階光同時掃過6P_1/2->6P_3/2的兩條躍遷
也讓綠光停在相連的躍遷上，得到兩條EIT重疊四能階系統的光譜。研究躍遷路徑的干涉現象。
第三階段，我們調整EOM的調製頻率使第二階段中的EIT分開
，並記錄其對應的偏振角度。
最後我們分析偏振角和振幅比值的關係可得X值，X~0.18，此
參數為宇稱不守恆中的解釋弱作用力一環的重要參數。目前所量測的數值與已知的量測與計算有明顯的差異，顯示重要的系統性，顯示重要的系統性誤差尚未被釐清。

In this thesis, we investigate the electromagnetically induced transparency(EIT) of Thallium. The phenomena is associated with the parity nonconservation. We represent the observed EIT spectrum, and apply the result to calculate the ratio between E2 and M1 in the 6P_1/2->6P_3/2E1-forbidden transitions. The probe laser is a quantum-dot(QD) external cavity diode laser , which is coupled into a fiber-based EOM and generates 10.5 GHz sidebands .
In the first stage of the experiment, the 535 nm coupling laser passes through the acoustic-optic modulator for amplitude modulation , then into the cell , which is heated to 600 degree. The frequency is at the 6P_3/2->7S_1/2 transition. Meanwhile, The 1283 nm QD laser scans through the 6P_1/2->6P_3/2 transition as the probe laser. We observed the six sub-Doppler EIT channels.
In the second stage, the probe light modulated by EOM scan through the two 6P_1/2->6P_3/2 transitions, and the green laser was stabilized in the connected transition to simultaneously perform two EIT channels in the laser four level system.That is to investigate the interference phenomena between the three pathways of the transition.
In the third stage, we adjust the modulation frequency of EOM to completely separate the EIT in the second stage to compare the EIT signal of different polarization angles. We analyze the relation between the polarization angle and the amplitude of signals to obtain chi=E2/M1 ~ 0.18. The parameter is important in the parity nonconservation experiment to extract the weak interaction.Currently,the measured number is different from the other published measurement.That indicates a significant systemically error is still unresolved.

第一章 ……………………1
第二章 ……………………4
第三章 ……………………13
第四章 ……………………30

[1]Tzu Ling Chen. Study of Cavity—Enhanced Atomic Parity Non-Conservation With Quantum Dot Laser Based NICE—OHMS Spectroscopy. Doctoral thesis,
104.

[2]Alexander Douglas Cronin. New techniques for measuring atomic parity Violation. Doctoral thesis, 1999.

[3]N.H. Edwards, SJ. Phipp, PEG. Baird, and S. Nakayama. Precise Measure-
ment of Parity NonconserVing Optical Rotation in Atomic Thallium. Phys.Rev. Lett., 74265472657, 1995.

[4]Joshua Harden, Amitabh Joshi, and Juan D Serna. Demonstration of double eit using coupled harmonic oscillators and rlc circuits. European journal of physics, 32(2) :541, 2011.

[5]Amitabh Joshi and Min Xiao. Electromagnetically induced transparency and its dispersion properties in a four—level inverted—y atomic system. Physics Letters A, 317(5—6):3707377, 2003.

[6]P. A. Vetter, D. M. Meekhof, P. K. Majumder, S. K. LamoreauX, and E. N.Fortson. Precise test of electroweak theory from a new measurement of parity nonconservation in atomic thallium. Phys. Rev. Lett, 74265872661, Apr 1995.
[7]余怡德陳應誠 光速減慢至每秒600 公尺- 原子的電磁波引發透明效應 物
理雙月刊23卷5 期，p. 572-578,2001