MODELING FLUORESCENCE COLLECTION FROM SINGLE MOLECULES IN MICROSPHERES - EFFECTS OF POSITION, ORIENTATION, AND FREQUENCY

We present calculations of fluorescence from single molecules (modeled as damped oscillating dipoles) inside a dielectric sphere. For an exc ited molecule at an arbitrary position within the sphere we calculate the fluorescence intensity collected by an objective in some well-defi ned detection geometry. We find that, for the cases we model, integrat ion over the emission linewidth of the molecule is essential for obtai ning representative results. Effects such as dipole position and orien tation, numerical aperture of the collection objective, sphere size, e mission wavelength, and linewidth are examined. These results are appl icable to single-molecule detection techniques employing microdroplets . (C) 1996 Optical Society of America