Abstract

Recent advances in fluorescence microscopy have made room temperature single molecule spectroscopy an active area of research. In this work, we investigate the room temperature spectral evolution of single sulforhodamine 101 molecules adsorbed on a silicate glass surface and covered by a PMMA polymer film. Single molecule emission spectra are taken and analyzed with a time resolution of 250 millisecond. Time correlation functions of single molecule spectral trajectories are obtained, with decay time constants inversely proportional to excitation intensities, demonstrating the spectral fluctuation is photo-induced in nature. A stochastic model is developed in order to account for the experimental observations. Understanding the origin of the spectral jumps encountered in the room temperature single molecule experiments is important for conducting further experiments to study chemical dynamics of single molecules in a variety of systems. The latest results of the further experiments will also be presented.

© 1996 Optical Society of America