Abstract

Control of a biological function has been accomplished based on the manipulation of the absolute quantum yield of retinal photoisomerization in bacteriorhodopsin under weak excitation conditions where only 1 from ~300 molecules absorbs a photon during an excitation cycle. Using tailored excitation light pulses found in optimization experiments we are able to manipulate the isomerization yield by nearly 50 % (both enhancement and suppression by ~23%) while keeping the number of absorbed photons constant.

© 2006 Optical Society of America