Dependence Of The Fluorescence Of A Single Impurity Molecule On Light Polarization In Birefringent Crystals (Pentacene In P-Terphenyl)

The most popular system for single molecule spectroscopy up to now is pentacene molecules introduced into p-terphenyl single crystal. P-terphenyl is a birefringent crystal and here arises a problem about the state of light polarization at the site of pentacene: the fluorescence intensity depends on the angle between the polarization and transition dipole moment of the molecule. This circumstance has found application in the measurement of the distance of the molecule from the crystal entrance surface [1]. In Ref.[1] formulae for finding the distance and the orientation of the dipole moment have been given and the respective values have been calculated. The aim of this paper is to derive more accurately formulae for these values, taking into account more precisely the properties of the electric field of the wave propagating in a birefringent crystal.