Random mode coupling

Figure 3.7 Random mode coupling due to microscopic heterogenaties.

As the parabohc index profile is not optimum for PMMA-based GI POFs, random mode couplings can affect pulse spreading owing to group delay averaging. 

Figure 3.12 Average power coupling coefficients between mode groups with principal mode numbers M and N for random mode coupling due to (a) microscopic heterogeneities...

A reactive species in liquid solution is subject to pemianent random collisions with solvent molecules that lead to statistical fluctuations of position, momentum and internal energy of the solute. The situation can be described by a reaction coordinate X coupled to a huge number of solvent bath modes. If there is a reaction... 

If the contribution of the localized eigenfunctions (scars or bouncing ball modes) in (8) is negligible, then all eigenfunctions ipn(x,y) are RGF. The complex coefficients in the superposition, cn, depend on the energy and the coupling between the billiard and leads and are not random as in the Berry function (2). Nonetheless the superposition of RGFs is also a complex RGF (W. Feller, 1971 M.I. Tribelsky, 2002)... 

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