| In this research, the steady and temporal properties of Two waves mixing (TWM) were studied in a Ce:KNSBN crystal with a He-Ne laser and a synchronous data recording system, and the process of TWM was analyzed under a bump beam chopped condition. As the results, firstly, some steady parameters were determined, including the gain coefficient г, diffraction efficiency of the volume grating η and response time t1 of TWM under different total incident intensity I0, ratio of two writing beams mo, angle between two writing beams 2θ and polarization conditions. Secondly, a new method was proposed to obtain two important coefficients of the Ce:KNSBN crystal, Rreff and Neff, by fitting the variation of response time as a function of 2θ . Thirdly, the temporal behavior of the pump beam, signal beam and fanning and the influence of fanning to TWM were carefully studied and analyzed under different incident conditions in TWM. Fourthly, the incident intensity threshold of the fanning effect in TWM was measured inthe Ce:KNSBN crystal, and it is about 20mW/cm , while using 632.8nm red light with e polarization as writing beam. Fifthly, a reasonable explanation to the phenomenon was given that the temporal behavior of TWM will be different while the signal beam opening time delays a different time after pump beam opened. Sixthly, in the experiment under a pump chopped condition, we found that a chopped pump will weaken the fanning development at the beginning of TWM. Finally, wave-coupling equations modified according to experiments, were implemented to simulate the dynamic process of the TWM and the theoretical calculated results are coincident with the experimental data. These results are helpful for understanding the photorefr active dynamic of TWM in Ce:KNSBN crystal and the influence of fanning to TWM, and provides fundamental data for the applications of doped KNSBN crystal in the fields of optical information processing and holographic storage.
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