Chain Length Dependence of the third-order Polarizabilities in Thiophene Oligomers

1 Chain length dependence of the third-order polarizabilities in thiophene oligomers 

In Table 6, we present the Jxxxx chain-axis components and the (7) average values of the third-order polarizabilities in thiophene oligomers ranging in size from 1 to 8 monomer repeat units. The evolution of (7) with chain length, illustrated in Fig. 15, can be divided into three parts [52]  

The evolution with chain length of the chain axis component fxxxx is very similar to that of the average value the contributions arising from electronic excitations along the chain axis actually dominate the third-order response. 

6 Geometric and Electronic Structure and Optical Response of Oligo- and Polythiophenes 

We stress that this description is in overall agreement with the general model of Mazumdar and co-workers [137-139]. 

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