Gao Chao,Wu Hongcai,Li Baoming,Yi Wenhui,Sun Jianping
(School of Electronics and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China)
Abstract: In order to investigate the nonlinear optical properties of a
soluble poly(paraphenylene) (PPP) derivatives, poly(2,5-dihexyloxy-1,4-phenylene)
(DHO-PPP) which could readily be solution-processed into films was synthesized by
oxidation coupling using iron chloride as catalyst. The solution and film of DHO-PPP show
very small absorption values at 532 nm in UV-Vis absorption spectra. The four diluted
chloroform solution samples of DHO-PPP were prepared and the third-order nonlinear optical
properties were studied with the backward degenerate four-wave mixing at 532 nm. By using
the relative measurement technique, the third-order nonlinear optical susceptibility and
the nonlinear refractive index are linearly increased with increasing the concentration of
the solution, while the hyperpolarizability of DHO-PPP remains a constant value of 1.78¡Á10-30esu.
When the concentration of the solution reaches 5 g/L, the third-order nonlinear optical
susceptibility and nonlinear refractive index of DHO-PPP are 6.31¡Á10-11esu and
1.65¡Á10-9esu, respectively, which implies that this polymer has good nonlinear
optical properties.
Keywords: poly (paraphenylene) derivative; degenerate four-wave mixing; third-order
nonlinear susceptibility; second-order hyperpolarizability; nonlinear refractive index