Technology Development of laser cooling of slicon atoms

最近，人们对凝聚态物理(如玻色-爱因斯坦与稀薄原子气体的凝聚)和原子物理(如原子光刻)等研究领域的极大兴趣，加速了在许多原子物种中证实原子与光的相互作用的趋势。因此，产生特定原子冷却波长的相干光的要求正在出现。然后提出了许多频率转换技术的方法，包括开发新的激光系统来满足上述需求，这些方法本身也推动了BEC的研究。因此，我们开发了一种新的相干光源来演示激光冷却电子领域中非常有吸引力的原子硅原子。这种相干光转换技术具有两级频率转换系统，外腔可产生252 nm的光。并重点研制了基于…的双谐振和频二次变频系统产生高功率、高稳定的252 nm光，充分满足激光制冷条件。在本论文中，我们通过充分理解和频腔的特性，成功地产生了高功率(154 MW)、高效率(8.4%)、稳频(均方根=1.4)、窄带宽(28.8 MHz)的252 nm光。由于到目前为止，我们已经使用线宽为470 GHz的纳秒掺钛蓝宝石激光器进行了硅原子的光电流光谱研究，因此，除了硅原子以外的其他原子的光谱可能包含在观察到的光谱区域内。另一方面，虽然我们研制的深紫外光连续波相干光源的线宽比硅原子的自然宽度(28.8 MHz)窄，但调谐范围约为1 GHz。本论文的目的是利用线宽为6 GHz的纳秒掺钛蓝宝石激光器，演示硅原子的光电流光谱，并在激光冷却跃迁附近对硅原子的光谱进行近距离测量。较少

Great interest in the research fields of condensated matter physics like Bose-Einstein Condensation with dilute atomic gas and of atomic physics like atom lithography recently accelerates the trend toward confirming the interaction of an atom with light among a lot of atomic species. Consequently, requests to generate the coherent light of specific atomic cooling wavelength are emerging. Then many approaches of frequency conversion techniques including the development of new laser systems to meet the above needs are proposed, and those approaches itself also drive the BEC research.A new coherent light source is therefore developed to demonstrate laser cooling of silicon atom, which is a very attractive atom in the electronics field. This coherent light conversion technique has 2-step frequency conversion systems with external cavities to generate 252-nm light. And the author mainly developed the 2nd frequency conversion system, which is made of doubly resonant sum frequency mixing, to … More generate 252-nm light with high power and high stability, which sufficiently fulfills the laser cooling conditions. In this thesis, the 252-nm light with high power (154 mW), high efficiency (8.4 %), frequency-stabilized (rms=1.4_10^<-2>) and narrow bandwidth output(<28.8 MHz) is successfully generated by fully understanding the characteristic properties of a doubly resonant sum frequency mixing cavity.Since we have performed the optogalvanic spectroscopy of silicon atoms until now using a nanosecond Ti : sapphire laser which had linewidth of 470 GHz, the spectra from some atoms other than silicon atoms may be contained in the observed spectral region. On the other hand, although the deep ultraviolet continuous-wave coherent light source which we have developed has a linewidth narrower than the natural width of the silicon atoms (28.8 MHz), the tuning range was 1 GHz approximately. The purpose of this thesis is to demonstrate the optogalvanic spectroscopy of the silicon atoms and then measure the spectrum of silicon atoms closely in the vicinity of the laser cooling transition by use of the nanosecond Ti:sapphire laser with the linewidth of 6 GHz. Less