NANOSECOND & PICOSECOND TRANSIENT SPECTROSCOPY

纳秒光谱学已经证明了广泛的 在整个生物学领域的应用。它允许识别 光触发过程中的中间物种。这 研究涉及纳秒的开发和维护 吸收光谱仪。该设备继续提供高性能 质量光谱从纳秒到秒的时间尺度，具有广泛的 样品处理的范围和改进的动力学分析软件。这个 可以记录激发的瞬变的吸收或增益谱的装置 通过运行在20赫兹的YAG激光器的脉冲。探测源是一个 用光纤将氙气闪光带到样品中。时间 分辨率是通过选通二极管阵列实现的。此外，我们还有 搭建了一套用两个Nd：YAG激光器运行的暂态吸收系统 具有填充光束轮廓的激光器。此配置将允许 用于探测具有以下产生的宽带光的瞬变 荧光染料能显著提高染料的S/氮比 瞬变光谱测量。此外，我们还添加了一个 将光学参量振荡器引入这种双YAG装置，它将 产生近红外和中红外频率，以便探测这样的过程 作为蛋白质构象动力学。一个皮秒系统，它将 产生稳定的放大连续谱，适用于广泛的泵浦和 重复频率增加的探测波长(单位为千赫 领域)正在开发中。这个系统可以耦合到双 用于常规采集的增强型二极管阵列检测系统 在“用户友好”的基础上进行光谱分析。

Nanosecond spectroscopy has demonstrated a wide range of applications over the whole of biology. It permits the identification of intermediate species in optically triggered processes. This research involves the development and maintenance of a nanosecond absorption spectrometer. This device continues to provide high quality spectra from the nanosecond to second time scale, with a wide range of sample handling and improved kinetic analysis software. The apparatus can record absorption or gain spectra of transients excited by pulses from a YAG laser running at 20Hz. The probe source is a xenon flash carried to the sample with an optical fiber. The time resolution is achieved by a gated diode array. In addition, we have constructed a transient absorption system which is run with two Nd:YAG lasers with filled-in beam profiles. This configuration will allow for probing of transients with broadband light generated from fluorescent dyes which will significantly improve the S/N of the transient spectral measurements. In addition, we have added an optical parametric oscillator into this dual YAG setup which will generate near and mid-IR frequencies in order to probe processes such as protein conformational dynamics. A picosecond system which will generate stable amplified continuum for a wide range of pumping and probing wavelengths with an increased repetition rate (in the kHz domain) is being developed. This system can be coupled to the dual intensified diode array detection system for routine acquisition of spectra on a "user-friendly" basis.