Degenerate four-wave mixing, third-order

Absorption spectroscopy, quartz crystal microbalance and electrical measurements and femtosecond degenerate four-wave mixing studies of third-order optical non-linearity... 

TEM and absorption spectrophotometry a large third order non-linearity was observed by degenerate four-wave mixing... 

Time resolved femtosecond degenerate four-wave mixing is based on the response of the third order polarisability. With a femtosecond pulse rotational levels are coherently prepared by a... 

Third-Order NLO Techniques. There is a wider range of third-order techniques commonly used to characterize materials, including electric field induced second harmonic generation (EFISH) (15, 16), third harmonic generation (THG) (17) and degenerate four wave mixing (DFWM) (18). EFISH and DFWM will be discussed briefly then... 

In a recent communication we reported that the third order nonlinear optical susceptibility of Pt, Pb, and H2 tetrakis(cumylphenoxy)phthalocyanines was large and varied substantially with the metal substituent. (1) The structure of these compounds is shown in Fig. 1. The susceptibility was measured by degenerate four-wave mixing at 1.064 pm, a wavelength far from the main absorption bands of phthalocyanines near 650 nm. The nonlinear susceptibility of the Pt phthalocyanine was about a factor of 9 larger than that of the Pb phthalocyanine and a factor of 45 larger than the metal free compound. 

The third order optical susceptibility was measured by degenerate four-wave mixing (DFWM). A single pulse at 1.064 pm with a full width at half maximum of 35 ps was selected from the output of a passively mode locked Nd/YAG laser and split into three... 

Poly(3-alkyl-a-thiophene) systems show significant third-order nonlinear susceptibilities ( ) Though, oligothiophenes have been studied for their third-order susceptibilities, accurate third-order optical nonlinearity data obtained by degenerate four-wave mixing or electric-field-induced second harmonic generation (EFISH) are difficult to attain reliably on samples with poor solubility characteristics (92MM1901). 

In the degenerate four wave mixing (DFWM) experiment the third-order susceptibility 3)(-tt>,tt>,-CL>,CL>) with degenerate frequencies can be determined [22]. This nonlinear susceptibility is directly proportional to the nonlinear refractive index n2, which is used to describe optically induced refractive index changes. An advantage of this technique is the possibility to record the temporal shape of the third-order nonlinear optical signal. 

Degenerate four-wave mixing (DFWM) Degenerate four-wave mixing (DFWM) is another well-known nonlinear technique based on third-order nonlinear susceptibility similar to CARS... 

Powell, C.E., Humphrey, M.G., Morrall, J.P., Samoc, M., Luther-Davies, B. Organometallic complexes for nonlinear optics. 33. Electrochemical switching of the third-order nonlinearity observed by simultaneous femtosecond degenerate four-wave mixing and pump-probe measurements. J. Phys. Chem. A 107, 11264-11266 (2003)... 

Third-order NLO properties have been described for liquid-crystalline phthalocyanine and porphyrin complexes. The values for the meso-genic cobalt(II), nickel(II), copper(II), zinc(ll) and vanadyl complexes of 5,10,15,20-tetrakis(4-w-pentadecylphenyl)porphyrin have been measured in benzene solution by the technique of degenerate four-wave mixing (DFWM) at 532 nm. The values varied between 1.5 and... 

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