Molecular systems for ultrafast optical switching: Controlling electron transfer reactions with femtosecond laser pulses

摘要

Rapid, reversible photoinduced electron transfer reactions are a class of photophysical phenomena that can be exploited to develop schemes for optical switching. Molecular electronic switches, wires, micro-sensors for chemical analysis, and opto-electronic components for use in optical computing are currently under active investigation. The principal advantages of using molecules in these applications are high component density, increased response speeds, and high energy efficiency. Since photoinduced electron transfer processes within molecules can take place on a picosecond time scale, it should be possible to produce efficient devices that respond very rapidly. Molecules that employ reversible electron transfer reactions for optical switching should possess both speed and photostability advantages over molecular switches based on photochemical changes in molecular structure. For this purpose the authors recently designed several molecular systems that display properties that may be exploited for optical switching. In this paper, two or more laser pulses are used to manipulate photochromic ion pairs that results from rapid reversible photoinduced electron transfer in complex donor-acceptor molecules.