Abstract

Observation of band shifts in the absorption spectra of in vivo carotenoids has been attributed to electric field effects generated by membrane potentials. This electrochromism is related to what is known as the Stark effect, a term which is used to describe the effect of an applied electric field on many physical processes. Previous in vitro studies of how electric fields effect the absorption spectra of molecules all have relied on applying the perturbing electric field by using external electrodes around a dielectric spacer containing the molecule to be studied. The maximum applied field in these examples has been between 0.5 MV/cm and 3 MV/cm. These electric field intensities are of the same magnitude as those thought to be present across the membranes studied in the in vivo experiments.

© 1994 Optical Society of America