Femtosecond Transient Grating Studies of Electron Transfer in Porphyrin and Chlorophyll Donor-Acceptor Molecules

Abstract

Transient grating experiments have been utilized to study a variety of condensed phase phenomena. Most of these studies are performed on transparent media, resulting in non-resonant probing of the material response of the system. Such experiments include the study of orientational dynamics in liquids, acoustic and optical phonon dynamics as they relate to phase transitions in solid state media, optical Kerr effects, intramolecular vibrations, etc. In its simplest form, the technique requires two beams to be temporally and spatially overlapped in the sample. An interference pattern is created, which modulates the real part of the index of refraction through the third order susceptibility (χ(3)). A phase grating results, through which a variably delayed probe beam incident on the sample may diffract and provide temporal information about the material response. Transient grating experiments have been utilized to study a variety of condensed phase phenomena. Most of these studies are performed on transparent media, resulting in non-resonant probing of the material response of the system. Such experiments include the study of orientational dynamics in liquids, acoustic and optical phonon dynamics as they relate to phase transitions in solid state media, optical Kerr effects, intramolecular vibrations, etc. In its simplest form, the technique requires two beams to be temporally and spatially overlapped in the sample. An interference pattern is created, which modulates the real part of the index of refraction through the third order susceptibility (χ(3)). A phase grating results, through which a variably delayed probe beam incident on the sample may diffract and provide temporal information about the material response.