Development of a Microsecond Time-resolved Infrared Spectrometer and Its Applications to Photochemical Intermediates

研制了一台时间分辨扫描红外光谱仪，它由球面光源、单色仪、多层螺旋CT探测器、箱形积分器、连续调Q激光和PC机组成。该光谱仪既能观察到时间分辨光谱(在频率扫描模式下)，又能观察到瞬变信号的时间变化(在时间扫描模式下)。它覆盖了7004200 cm~(-1)的光谱范围，时间分辨率为1mus。在狭缝宽度为5 mm(700 cm；d1-1；d1和60 cm；-1；-1；4000 cm；-1)的情况下，可以检测到小到10^4的一个部分的强度变化，典型的扫描速度为100 cm^-1/5分钟。这种光谱仪的高性能是通过使用高重复频率(750赫兹)的光化光源和交流耦合检测方案来实现的。用该光谱仪观测了不含金属的tau形式的酞菁超细粒子的时间分辨红外光谱。阐明了光生三重态激子的衰变动力学。还观察到了反式聚乙炔中光生带电孤子的衰变动力学。

A time-resolved scanning infrared spectrometer had been constructed which consists of a globar light source, a monochromator, an MCT detector, a boxcar integrator, a cw Q-switch ND:YAG laser, and a personal computer. Both the timeresolved spectra (in the frequency scanning mode) and the temporal change of the transient signals (in the time scanning mode) can be observed with this spectrometer. It covers the spectral range of 700 4200 cm^<-1> with the time resolution of 1 mus. Intensity changes as small as one part in 10^4 can be detected with a slit width of 5 mm (6 cm^<-1> at 700 cm@>D1-1@>D1 and 60 cm^<-1> at 4000 cm^<-1>) and with a typical scanning rate of 100 cm^<-1>/5 min. High performance of this spectrometer has been achieved by the use of a high repetition rate (750 Hz) laser for the actinic light source combined with an ac-coupled detection scheme. Time-resolved infrared spectra of metal-free tau-form phthalocyanine fine particles have been observed with this spectrometer. The decay dynamics of photogenerated triplet exciton have been elucidated. The decay dynamics of photogenerated charged solitons in trans-polyacetylene have also been observed.