LASER SPECTROSCOPY AND PHOTOCHEMISTRY IN MICROMETER SMALL VOLUMES

The importance of micrometre dimensions in photochemistry is considered, and a systematic study on laser spectroscopy and photochemistry in small micrometre volumes is reported. To measure chemical reactions in the small volumes, submicrometre space- and picosecond time-resolved fluorescence and transient absorption spectroscopy was developed by employing a confocal laser scanning microscope. Laser-trapping phenomena were used for choosing small (micrometre-sized) materials as well as reagents, transferring them to a certain position with micrometre resolution and inducing chemical reactions. Combined with spectroscopic analysis, the laser-trapping technique was developed as a laser manipulation-spectroscopy-reaction method. Utilizing these methods, characteristic micrometre-sized effects were confirmed in the excimer dynamics in microdroplets and photoresponse of gels. Some small (micrometre-sized) reaction fields, which are crucial for conducting chemical reactions, were created by microfabrication techniques. Summarizing our trials, our goal to create an integrated chemical system named microphotoconversion is presented.