Radiation pattern of fluorescence from molecules embedded in small particles: general case.

A method is presented for calculating and analyzing the angular distribution of fluorescent emission from randomly oriented anisotropic molecules embedded in small dielectric particles with the nonzero reorientation angle between absorption and emission moments suggested by physical considerations now taken into account. Calculations performed on the basis of this method are compared with some of the available experimental data for fluorescent dye molecules embedded in microspheres, and good quantitative agreement is found. It is shown how fitting the computed results to experimental data determines an effective reorientation angle between absorption and emission transition moments. A more definitive test to which the model could be subjected is described.