IR-Vis sum-frequency generation circular-dichroism studies on ultra-thin films of chiral molecules.

我们研究了chihalmolecules超薄膜的IR-Vis和频产生圆二色性，这在生物学和/或医学上的应用已经引起了相当大的关注。该技术可能提供比任何传统技术高10^8倍的效率来研究分子的手性。我们用LBO晶体改造了传统的ps-YAG激光器和OPG/OPA系统。利用AgGaS_2晶体上的基态YAG和OPA的空转光束的差频得到红外激光束。我们在可见光束中插入四分之一波片，产生左右偏振光，然后与红外光束混合，得到SFG-CD信号。实验中使用的样品是铁电和反铁电液晶分子。我们成功地获得了单分子层厚样品的SFG-CD信号。我们对室温离子液体的气/液界面结构进行了扩展的IV-SFG研究。与此实验相关，我们还利用近边x射线吸收精细结构光谱对分子构象进行了研究。

We have investigated IR-Vis Sum-Frequencey-Generation Circular Dichroism of the ultra-thin films of chihalmolecules, which has been attracted considerable attention for biological and/or medical application. This technique may possibly provide 10^8 times more efficiency than those from any conventional techniques to study the chirarity of the molecules.We have reformed our old conventional ps-YAG laser and OPG/OPA system with LBO Crystal. We obtained IR laser beams by taking differential frequency of a fundamental YAG and the idler beam of OPA on a AgGaS_2 crystal. We have inserted a quater-wave plate into a visible beam to make left and right polarized light, and then mixed with the IR beam to obtain SFG-CD signal.The samples used in the experiment were ferro-and antiferro-electric liquid crystal molecules. We have successfully obtained SFG-CD signal for mono-molecular-layer thick samples. We have extended IV-SFG studies on the air/liquid interface structure of room temperature ionic liquids. In relation to this experiment, we have also performed the studies of molecular conformation by using near edge X-ray absorption fine structure spectroscopy.