Technology Development of laser cooling of slicon atoms

近年来，人们对玻色-爱因斯坦凝聚等凝聚态物理和原子光刻等原子物理的研究兴趣浓厚，加速了在众多原子种类中确认原子与光相互作用的趋势。因此，产生特定原子冷却波长的相干光的需求正在出现。在此基础上，提出了多种频率转换技术的发展途径，包括发展新型激光系统，这些途径本身也推动了BEC的研究。这种相干光转换技术具有两步频率转换系统，具有外部腔体以产生252 nm的光。作者主要研制了双谐振和频二次变频系统， 关于我们 产生具有高功率和高稳定性的252-nm光，其充分满足激光冷却条件。本论文在充分了解双谐振和频腔特性的基础上，成功地产生了高功率（154 mW）、高效率（8.4%）、稳频（rms= 1.4 ~ 10 ^<-2>）、窄带宽（&lt;28.8 MHz）的252 nm光，由于我们已经用线宽为470 GHz的纳秒钛宝石激光器进行了硅原子的光电流光谱实验，所以在所观察到的光谱范围内可能包含了硅原子以外的其他原子的光谱。另一方面，虽然我们已经开发的深紫外连续波相干光源具有比硅原子的自然宽度（28.8MHz）窄的线宽，但是调谐范围大约为1GHz。本论文的目的是利用线宽为6 GHz的纳秒钛宝石激光器，演示硅原子的光电流光谱，并在激光冷却跃迁附近测量硅原子的光谱。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