Abstract

We show that ultrasensitive microdroplet-stream fluorescence techniques combined with surfactant forms of Rhodamine dyes can be used to probe single molecules on the surfaces of spherical microcavities. Individual octadecyl Rhodamine B molecules, shown previously by ensemble measurements to be localized and oriented at the surfaces of liquid microspheres, were spatially photoselected primarily along great circles lying perpendicular or parallel to the detection axis by use of polarized laser excitation. A polarization dependence is observed in the distribution of single-molecule fluorescence amplitudes that can be interpreted qualitatively in terms of position-dependent fluorescence-collection efficiencies.

© 1998 Optical Society of America

Real-time observation of single-molecule fluorescence in microdroplet streams

M. D. Barnes, N. Lermer, C.-Y. Kung, W. B. Whitten, J. M. Ramsey, and S. C. Hill
Opt. Lett. 22(16) 1265-1267 (1997)

Excitation localization principle for spherical microcavities

H.-B. Lin, J. D. Eversole, A. J. Campillo, and J. P. Barton
Opt. Lett. 23(24) 1921-1923 (1998)

Collection of fluorescence from single molecules in microspheres: effects of illumination geometry

Steven C. Hill, Michael D. Barnes, William B. Whitten, and J. Michael Ramsey
Appl. Opt. 36(19) 4425-4437 (1997)

Near-field scanning optical microscopy of single molecules by femtosecond two-photon excitation

Michael K. Lewis, Peter Wolanin, Ari Gafni, and Duncan G. Steel
Opt. Lett. 23(14) 1111-1113 (1998)

Cavity-mode selection in spontaneous emission from oriented molecules in a microparticle

Stephen Arnold, Stephen Holler, Noel L. Goddard, and Giora Griffel
Opt. Lett. 22(19) 1452-1454 (1997)