Investigation of Zeeman Effect of Molecular Iodine Hyperfine Transitions at 548 nm

• Main Authors: Wang, Chun-Ju, 王淳㚢
• Other Authors: Wang, Li-Bang
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/81935963528701812868

碩士 === 國立清華大學 === 物理系 === 102 === 　　In many experiments, the iodine-stabilized laser system serves as an optical frequency standard. However, the geomagnetic field is usually not taken into consideration when measuring frequencies of molecular iodine hyperfine transitions. Up to now, the research on how the magnetic field affects absorption spectra of I2 hyperfine transitions is very limited because I2 is not sensitive to the magnetic field. The reason why spectra changes under the magnetic field is the difference in g-factor for different energy levels. As a result, each transition between Zeeman sublevels will exhibit different Zeeman shift. 　　In our experiment, the absorption spectra of 127I2 R(136) 27-0, R(86) 25-0, P(28) 24-0 and R(32) 24-0 hyperfine transitions are observed, and the linewidth of a10-lines is measured. By the superposition of several Lorentzian profiles, the difference of g_F-factors between the excited and ground state is calculated, and the average values of that under different magnetic fields are 0.0935, 0.0765, 0.0617 and 0.0571 respectively. Although the effect of the magnetic field on 127I2 hyperfine transitions at 548.5 nm is not theoretically investigated, the observed spectra can be reasonably explained and expected by the difference of g_F-factor obtained. In the future, more 127I2 hyperfine transitions under different magnetic fields can be investigated and better–controlled magnetic fields can be applied to get more precise g_F-factors.