近代精準原子光譜實驗中，鉈原子(Thallium, Tl)在驗證宇稱不守恒原理中扮演一個重要的角色。本論文主旨為研究鉈原子束系統中準穩態(metastable
state)6P3/2與激發態(excited state)7S1/2間的躍遷，利用535nm雷射光源觀察原子被激發後所產生之雷射誘發螢光光譜；然而對鉈原子束系統中，在自然熱平衡分布下，由統計力學知主要原子數population皆集中在基態(ground state)6P1/2上，因此準穩態6P3/2上幾乎沒有原子，因此535nm螢光光譜的完成必須仰賴另一道377nm雷射光源的光學幫浦(optical pumping)效應，並利用躍遷選擇規則(selection rule)將原子從6P1/2能階經由lamda型能階系統轉移到特定的準穩態6P3/2超精細結構(hyperfine structure)能階上。本實驗利用755nm鈦藍寶石(Ti-Sapphire)雷射經倍頻共振腔產生377nm雷射作為光學幫浦效應之光源，同時利用1070nm摻銣釩酸釓晶體(Nd:GdVO4)雷射經摻氧化鎂週期反轉鈮酸鋰晶體(MgO doped periodicallypoled lithiumniobate, MgO:PPLN crystal)倍頻產生的535nm雷射作為螢光光譜的激發光源。利用377nm雷射作為選擇器激發某些超精細能階與同位素，本論文展示了原子束中每個躍遷的535nm解析光譜，也將其與陰極中空放電管中的無都普勒效應光譜作比較，上述結果可以用來作為未來鉈原子lamda型三能階雷射冷卻技術以及原子束與宇稱不守恒有關之高解析度1283nm M1躍遷光譜。

In modern precision atomic spectroscopy, thallium(Tl) plays an important role in testing Parity Nonconservation(PNC). The purpose of this thesis is to study transition between metastable state 6P3/2 and excited state 7S1/2 in atomic beam of Tl using 535nm laser to observe laser-induced fluorescence spectrum from metastable atom. As the thermal distribution of atomic beam, the most population is at ground state 6P1/2, due to the large ground state fine structure splitting. There is nearly no population at 6P3/2 metastable state. To accomplish 535nm spectrum, it is needed
optical pumping by 377nm laser to transfer atoms from 6P1/2 to specific energy level with the help of the selection rule. One of the light sources in the experiment is a 377nm laser which is frequency-doubled by a doubling cavity with 755nm Ti-Sapphire laser. The other is a 535nm laser which is also frequency-doubled by a MgO:PPLN with 1070nm Nd:GdVO4 laser. With the characteristics of exciting Tl atom to 7S1/2, 535nm laser can be an important light source of detecting if there is absorption resulting in weak E1-forbidden transition between 6P1/2 and 6P3/2. Using 377nm laser as a selector that optical pumped only some certain hyperfine levels and isotope, this thesis performs 535nm spectrum in atomic beam to clearly resolved all the transitions. We also compared these doppler-free spectrum with the hollow cathode discharge lamp (HCL). These results can be applied to the future experiments of lambda-type laser cooling of thallium and the high resolution atomic beam spectroscopy of the M1 transition of 1283nm for atomic parity violation measurement.

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