Highly Sensitive Optical Waveguide Detection of Transient Species in Langmuir-Blodgett Films upon Pulsed Laser Excitation
Highly Sensitive Optical Waveguide Detection of Transient Species in Langmuir-Blodgett Films upon Pulsed Laser Excitation
复制标题
脉冲激光激发下 Langmuir-Blodgett 薄膜中瞬态物质的高灵敏度光波导检测
DOI：
10.1080/10587259708042783
复制
发表时间：
1997
影响因子：
0.7
通讯作者：
Kyoichi Sasaki
中科院分区：
文献类型：
--
作者：
T. Nagamura;Daizo Kuroyanagi;Kyoichi Sasaki
摘要用光波导(OWG)方法灵敏地检测了脉冲激光激发超薄朗缪尔-布洛杰特(LB)薄膜的瞬时组分。将双十八烷基二甲基铵按1：5和1：50的比例分别与双十八烷基二甲基铵以1：5和1：50的比例混合在LB膜中，在OWG表面制备了两亲性四苯基卟啉。这些薄膜是在脱气环境中用ns级的Nd：YAG激光器的二次谐波激发的。用该方法检测了激发态三重态卟啉在只有两个单分子膜的LB膜中的瞬时吸收。与传统的正常入射测量相比，它的灵敏度大约提高了数百倍。不同摩尔比的激发态三重态卟啉在LB膜中的衰减动力学不同，这归因于生色团的不均匀分布。
Abstract Transient species upon pulsed laser excitation of ultrathin Langmuir-Blodgett (LB) films was detected sensitively by the optical waveguide (OWG) method. Amphiphilic tetraphenylporphyrin in mixed LB films with dioctadecyldimethylammonium at 1:5 and 1:50 were prepared on the surface of OWGs. These films were excited with the second harmonics of a ns Nd: YAG laser in degassed environment. Transient absorption of excited triplet porphyrins in LB films with only two monolayers was detected by the present method. It was about hundred times increase of sensitivity as compared with a conventional normal incidence measurement. Different decay dynamics were observed for excited triplet state porphyrins in LB films depending on the molar ratio, which was attributed to inhomogeneous distribution of chromophores.