Author:

Keywords:

scanning optical microscopy, exciton, dynamics, photophysics, Science & Technology, Physical Sciences, Technology, Optics, Spectroscopy, SCANNING OPTICAL MICROSCOPY, EXCITON, DYNAMICS, PHOTOPHYSICS, 0205 Optical Physics, 5102 Atomic, molecular and optical physics

Abstract:

The structure of the luminescence anisotropy spectrum of J-aggregates of a thiocarbocyanine dye 3,3'-disulfopropyl-5,5'-dichloro-9-ethylthiacarboxyanine (THIATS), revealing the Davydov splitting of the exciton band, is studied at different (including anti-Stokes) excitation wavelengths. Upon excitation of luminescence at the upper Davydov component in absorption, the luminescence anisotropy varies from +0.07 at the half-maximum to -0.1 at the center of the luminescence band. The efficient alignment of aggregates in the liquid how in a rotating cell and an influence of this alignment on the luminescence anisotropy spectrum are found. The relationship between these results and the microscopic and macroscopic structure of J-aggregates is discussed.