Logo image
光學幫浦鉈原子6P3/2準穩態
Thesis

光學幫浦鉈原子6P3/2準穩態

陳正賢
Masters, 國立清華大學, 物理系
2013

Abstract

原子束 陰極中空放電管 光學幫浦 躍遷選擇規則 Thallium Tl atomic beam hollow cathode discharge lamp selection rule
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.

Metrics

1 Record Views

Details

Logo image