利用中空陰極放電管研究鉈原子之光阻抗與飽和吸收光譜

Optogalvanic and Laser Spectroscopy of Thallium Using a Hollow Cathode Lamp

林長義

指導教授 ： 劉怡維

國立清華大學/理學院/物理學系/博士(2012年)

https://doi.org/10.6843/NTHU.2012.00400

摘要

中空陰極放電管內因為高壓放電的緣故將會導致鉈金屬脫離陰極束縛，因此放電管內就產生了許多熱運動的鉈原子。我們詳細研究了鉈放電管和外來雷射光共振時產生的現象，觀察到了一些特別的行為。本論文會展示雷射光在377 奈米的鉈原子躍遷頻率時的光阻抗和飽和吸收光譜，並且和螢光光譜一起做分析比較。 另外也利用了聲光調制器產生兩個頻率不同的泵光，再使用了調制傳遞的技巧，將得出的兩個蘭姆凹陷訊號相減，得到了「似色散譜線」。我們使用了這個「似色散譜線」來做雷射穩頻，此穩頻結果可以用在將來的雷射冷卻鉈原子實驗上。

關鍵字

中空陰極放電管 ； 鉈 ； 光阻抗 ； 飽和吸收 ； 蘭姆凹陷 ； 雷射穩頻 ； 聲光調制 ； 調制傳遞 ； 似色散 ； 螢光

並列摘要

A thallium hollow cathode lamp, which provides high density atomic vapor using sputtering process, is a compact atomic source for spectroscopy study. The interaction between this lamp and incoming light on resonance frequency has been well studied. In this thesis, both optogalvanic spectra and saturation absorption spectra in 377 nm transition of thallium are studied and in comparison with laser induced fluorescence. Moreover, a dispersive- like signal is obtained as a differential signal between two saturation absorption lamb-dips results from by two pump beams with a frequency difference derived from an acousto-optic modulator. One of the beams is frequency shifted by the modulator. This method combines the approach of difference of two frequency shifted lamb-dips and modulation transfer technique. The dispersive- like signal is used for laser frequency stabilization is used for the future laser cooling experiment.

並列關鍵字

hollow cathode lamp ； Thallium ； opotogalvanic ； saturation absorption ； lamb dip ； laser frequency stablization ； AOM ； modulation transfer ； dispersive- like ； fluorescence

參考文獻

[33] Christopher J. Foot, Atomic physics. (Oxford, 2005)

[1] T. D. LEE and C. N. YANG, “Question of parity conservation in weak interactions,” Phys. Rev. 104, 254 (1956).

[2] C. S. Wu et al., “Experimental test of parity conservation in beta decay,” Phys. Rev. 105, 1413 (1957).

[3] M. A. Bouchiat and C. Bouchiat, “I. parity violation induced by weak neutral currents in atomic physic,” Phys. Lett. B48, 111 (1974).

[4] P. G. H. Sandars, “The electric dipole moment of an atom,” Phys. Lett. 14, 194 (1965)