Using Photochemical Hole Burning to Map Local Electric Fields

Abstract

Octatetraene can be photoisomerized even when it is incorporated in a low temperature n-hexane crystal. When this is done by irradiating the zero phonon component of the S0→S1 origin band with a single frequency laser, very narrow (less than 10 MHz) persistent holes can be burned. We have used this increase in resolution to study the effect of an external electric field on the S0→S1 excitation energy: typical results are shown in Figure 1.