Picosecond degenerate four-wave mixing

Picosecond Degenerate Four-Wave Mixing Experiments... 

Puech, K., Blau, W., Grund, A., Bubeck, C., Gardenas, G. Picosecond degenerate four-wave mixing in colloidal solutions of gold nanoparticles at high repetition rates. Opt. Lett. 20, 1613-1615 (1995)... 

DENIS W.M., BLAU W. and BRADLEY D.J., (1985), "Picosecond Degenerate Four Wave Mixing in Soluble Polydiacetylenes" Appl. Phys. Lett., 47t 200-202. 

Degenerate four-wave-mixing (DFWM, Section 10.2.3) in conjugated polymers has also been explored. Its use in optical image correlation has been demonstrated using Durham-route PAc and similar polymers. The very large optical non-linearity of PAc, Table 9.3, and the fast electronic response allow correlation to be performed with sub-picosecond laser pulses. The poor stability of PAc prevented this laboratory demonstration being turned into a practical device. 

A novel pump-probe degenerate four-wave mixing technique was introduced to study the excited state enhanced nonlinear optical response in polymers [7]. In this technique (see Fig, 3) a picosecond laser pulse at w, is divided into three beams... 

More recently, Schmid et al. [12] have shown that a separation of the different contributions to the degenerate four-wave mixing signal can be obtained by a modulation technique two of the incoming laser beams are chopped at different frequencies /, and /2 and the detection occurs at special combination frequencies of /, and /2- This technique was applied to the measurements of the third- and fifth-order autocorrelation functions of a picosecond laser using a polydiacetylene single crystal. 

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