Abstract

The first step in vision, the cis-trans isomerization of the chromophore in the retinal pigment rhodopsin, is a highly efficient chemical reaction which is initiated by the absorption of a single photon.¹ The molecular dynamics of this important photochemical process were recently resolved for the first time using 10 fs blue-green optical pulses.^2,3 These measurements revealed that the formation of the primary photoproduct is essentially complete in only 200 fs. The unprecedented speed of this reaction raises a number of questions about the fundamental processes which drive the isomerization.

© 1994 Optical Society of America