<title>Picosecond Absorption Spectroscopy</title>

Abstract

Following a brief description of the double beam picosecond spectrometer, we present two examples taken from photochemistry and photobiology.At first, results are presented on the nonradiative electronic relaxation (internal conversion and intersystem crossing) of photoexcited acridine. Subsequently, the nature of the primary steps in photosynthesis is considered. Picosecond absorption spectroscopy results are given that suggest a new mechanism for the photooxidation of bacteriochlorophyll.