Investigation of Femtosecond Time-resolved Optical Multichannel Spectrometer

Ultrafast time-resolved spectroscopy provides a pewerful technique for studying the nonlinear optics,solid state physics, chemical reaction dynamics, energy trnsfer and relaxation,dynamics of biolotical processes and coherent spectroscopic techniques.In this paper we report a femtosecond time-resolvedoptical multichannel spectroscopic arrangement.This arrangement consists of a femtosencond Ti sapphire laser pumped by argon ion Which Produces 100fm laser pulses centered between 720-980nm an improved variety of OMA-Ⅱ,a 386 computer and an optical system. Laser pulses are doubled with a thin LBO crystal.The time resolution of this spectroscopic arrangement was ～120fs and spectral resolution was less than 1 nm.Using this spectrometer we investigated the energy transfer and electronic excitation transport in photosystem Ⅱ reaction center. Recently we have measured the variation in difference absorptivity for the core complex of PSⅡ reauction censed and PSⅡ granule under laser excited and not excited. Charge Separation time was ～3ps with blue light exdtation.