Study Of Photovoltaic Space Optical Solitons In Photorefractive Polymer

Because the photorefractive spatial soliton can be produced at very low power levels, and has a high application value in optical computing, all-optical switching, holographic storage, and other fields. Therefore, in recent 20 years, more and more research has been carried out on photorefractive spatial soliton.Photorefractive effect is first discovered in crystal, since then a large number of theoretical and experimental analysis has been done on the spatial soliton in crystal, and the research on the soliton in crystal has become nearly perfect. However, because crystals have many shortcomings during its production process, people have taken more and more attention on the photorefractive polymer which is cheap and malleable. Moerner et al have established the orientation enhanced model by taking research on the characteristics of photorefractive polymers and the formation mechanism of spatial solitons, which is the theoretical foundation of the spatial soliton in photorefractive polymers.In this paper, the previous orientation enhancement model is modified according to the new orientation enhancement effect of photovoltaic photorefractive polymer. Based on the new orientation enhancement model, The space charge field expression in open and closed circuit is studied respectively, and futher more obtained the soliton solution as well as the generation conditions of bright and dark photovoltaic spatial solitons; the normalized intensity distribution curves and soliton FWHM of the bright and dark photovoltaic spatial solitons is obtained by numerical simulation. It is proved theoretically that the generation of photovoltaic spatial solitons in photorefractive photovoltaic polymer PVK-PBA:DR1:TNF is possible. The influence of partial pressure resistance on the FWHM of optical soliton in closed circuit is studied, and the results show that we can change the external pressure resistance to get the soliton FWHM that we needed.The time differential equation of space charge field under open-circuit conditions which generated in photorefractive polymer that having photovoltaic effect, and based on this result, the time-space charge field expression is achieved according to the boundary conditions. And further the variations of normalized intensity distribution curves and soliton FWHM of the bright and dark photovoltaic spatial solitons with time is obtained, and the temporal behavior of photovoltaic spatial solitons in open- circuit is discussed.