レーザーの空間特性を生かすレーザー光化学的手法は固体の分子ダイナミックスの研究に極めて有効で，我々はそのためのいくつかの分光計測法を開発してきた。第１に正，全，拡散反射分光法の時間分解能の向上，第２に時間分解・空間分解分光法の開発，第３に超高速画像観察法の開発である。それらを駆使することにより単なる光物理化学初期過程の解析ではなく，電子励起がモルホロジー変化に至るその時間発展を調べることが可能になってきた。

Briefly history of time-resolved spectroscopy is reviewed and, where gas and solution phases have been studies in detail. For solids, films, colloids, and devices now total intend reflection, specular reflection, and diffuse reflectance spectroscopies are useful, so that we have improved their time resolution to ps/fs for the first time. As solid systems are usually in homogeneous, time- and space- resolved spectroscopy was developed by combining pulsed lasers and various microscopes. Also time-resolved imaging is very fruitful to elucidate electronic relaxation and morphological change induced by laser excitation. By utilizing these pump-probe methods we have revealed laser-induced phnomena; laser-induce expansion / contraction of polymer films, fs discrete etching of organic solids, and cooperative photoisomerization of organic crystals, and so on.