A single molecule as a probe of optical intensity distribution

Single terrylene molecules embedded in microscopic p-terphenyl crystals are identified with the technique of fluorescence excitation spectroscopy. By use of the architecture of a scanning-probe microscope at T = 1.4 K, a sing le molecule is scanned through an excitation laser beam while the fluoresce nce signal is recorded. In this manner we have mapped the intensity distrib ution in a one-dimensional optical standing wave, demonstrating the potenti al of a single molecule as a nanometric probe. We discuss future experiment s aimed at combining the high spatial and spectral sensitivity of a single molecule. (C) 1999 Optical Society of America.