Highly sensitive time-resolved fluorescence measurements of ultra-thin films upon guided wave mode or surface plasmon resonance excitation and applications

我们已经在导波模式或表面等离子体共振激发下实现了超薄薄膜的高灵敏度时间分辨荧光测量，并将其应用于化学传感、分子光子学和超薄聚合物薄膜中分子运动的非接触评估。主要成果如下：利用表面等离子体共振（SPR）或导波模式（GWM）下的增强倏逝光作为激发光源，研制了一种新型的时间分辨荧光测量系统。我们证明了高灵敏度、快速响应和高度可逆的二氧化氮、一氧化氮和氧化亚氮在ppm至亚ppm水平上的传感已经实现了荧光测量在激发各种染料掺杂脱氧核糖核酸（DNA）和疏水DNA薄膜上自旋涂覆在薄银膜上，电场增强的倏变光在spr3。利用光致电子转移和氧化还原活性离子对之间的逆反应，对π-电子体系进行短暂膨胀，在固体薄膜中获得了更大的波长区域。该聚合物薄膜可应用于电信系统的太赫兹全光信息处理。用GWM或SPR激发法研究了分散在聚乙烯醇或聚三环癸烷超薄膜上的染料的荧光寿命。染料在超薄膜界面或表面的荧光行为明显不同于在体态下的荧光行为。基于低折射率聚合物和光响应聚合物组成的复合GWM几何结构的光致复折射率变化，提出了高灵敏的超快全光调制方法。与简单的传输型器件或金属薄膜中GWM的几何形状相比，本装置可以提供高度增强的探头光变化。一种光电致变色聚合物（如上3所示）在这种几何结构中被用来演示飞秒激光激发时的超快反射控制。少

We have achieved highly sensitive time-resolved fluorescence measurements of ultra-thin films upon guided wave mode or surface plasmon resonance excitation and their applications to chemical sensing, molecular photonics and non-contact evaluation of molecular motion in very thin polymer films. Major achievements are as follows :1.A novel time-resolved fluorescence measurement system was developed by using enhanced evanescent light at surface plasmon resonance (SPR) or guided wave mode (GWM) as an excitation light source.2.We demonstrated that highly sensitive, fast responsive and highly reversible sensing of nitrogen dioxide, nitric oxide, and nitrous oxide at a ppm-to-sub-ppm level has been achieved by fluorescence measurements upon excitation of various dye-doped deoxyribonucleic acid (DNA) and hydrophobic DNA thin films spin-coated on a thin silver film by electric field enhanced evanescent light at SPR.3.Ultrafast and large absorption change in the optical telecommunication wavelen … More gth region was achieved in solid films by making transitory expansion of a π-electronic system with photoinduced electron transfer and reverse reactions between redox-active ion pairs. This polymer film may be applied to terahertz all optical information processing in the telecommunication system.4.Fluorescence lifetimes of dyes dispersed in ultrathin films of poly(vinyl alcohol) or polytricyclodecane were examined by GWM or SPR excitation. The fluorescent behavior of the dyes at interface or surface of ultrathin films was strongly suggested to be different from that in the bulk state.5.Highly sensitive ultrafast all-optical light modulation was proposed on the basis of photoinduced complex refractive-index changes in composite GWM geometry composed of a low-refractive-index polymer and a photoresponsive polymer. The present device can give highly enhanced changes of probe light as compared with simple transmission-type devices or the GWM geometry in a metal thin film. A photoelectrochromic polymer (shown above 3) was employed in this geometry to demonstrate ultrafast reflectance control upon femtosecond laser excitation. Less