Abstract

A new frequency-domain instrument is described which allows the determination of picosecond rotation correlation times by monitoring fluorescence-anisotropy decay. In this instrument, a mode-locked argon-ion laser provides the high-frequency excitation source for the fluorophore (Figure 1). The resulting frequency-domain emission is measured with a radio-frequency spectrum analyzer. Calcite polarizers are used to selectively monitor the polarization of the emission radiation parallel and perpendicular to the plane of polarization of the excitation source. Data collection with the new instrument is very rapid. Furthermore, the signal-averaging makes this instrument applicable to weakly fluorescent species.

© 1987 Optical Society of America