OPTICALLY HETERODYNED POLARIZATION SPECTROSCOPY - MEASUREMENT OF THE ORIENTATIONAL CORRELATION-FUNCTION

Polarization spectroscopy has been developed as a useful method for the investigation of molecular reorientation in both liquid phase solutions and in the gas phase. This technique has the advantage of measuring a single particle orientational correlation function directly but the disadvantage of averaging over rotation in all electronic states. Described and characterized herein is a variant of this technique, optically heterodyned polarization spectroscopy, which is able to disentangle various contributions to the signal and determine the rotational relaxation of the solute molecule in different electronic states independently. This work also demonstrates the measurement of the normalized value of the orientational correlation function at time zero, r(0), without extensive normalization of laser parameters. Lastly, various technical advantages of the optically heterodyned method are discussed. © 1990 American Institute of Physics.