Figure 3
From: Conformation and physics of polymer chains: a single-molecule perspective
Experimental techniques used in single-molecule spectroscopy of polymers. (a,b) Principle of measurement of absolute shape and orientation of three-dimensional absorption ellipsoid by a combination of (a) wide-field epi-illumination microscopy and (b) total internal reflection microscopy. Polarization-modulated fluorescence intensity traces from individual molecules (insets in microscopic images) are fitted to theoretical equations to obtain the ratio r of the ellipsoid axes and the polar angles of its orientation. (c) Principle of determination of the polar angles ϕ and θ of a single emitting dipole by defocused fluorescence imaging. Modified after Ref. 17, reproduced with permission (© 2009 Wiley-VCH).
