匹配高斯光束在耗散晶体中的孤波演化及偏转特性

Solitary evolution and deflection of matching Gauss beam in dissipative crystals

研究了匹配的高斯光束在加外电场的耗散型光伏光折变晶体中的动态演化及其偏转特性.结果表明,对于给定的耗散系统,若该系统能支持某一特定的耗散全息屏蔽光伏明孤子,也可能找到与之相匹配的高斯光束,则该匹配的高斯光束能在此给定的耗散系统中演化成稳定的屏蔽光伏空间孤子.同时,考察了扩散效应对此匹配的高斯光束的影响,结果显示,扩散效应将造成此匹配的高斯光束孤波在演化过程中产生偏转现象,而且其偏转过程与之相对应的明孤子的偏转过程具有极其类似的特征.通过比较研究匹配的高斯光束与耗散全息屏蔽光伏明孤子的偏转特征曲线,我们发现,对于匹配的高斯光束,其空间偏转的数值计算结果与明孤子偏转的解析计算结果非常接近.总之,在耗散系统中,匹配的高斯孤波的动态演化特性(包括偏转过程)与耗散全息屏蔽光伏明孤波的演化特性是相符合的.因此,人们往往可直接用匹配的基模高斯光束代替耗散全息屏蔽光伏明孤波,为理论分析和实验研究提供了便利.

The solitary evolution and deflection of matching Gauss beam have been investigated in biased dissipative photovohaic- photorefractive crystals. For a given dissipative system that supports a determinate dissipative screening-photovohaic soliton （DI-ISP）, one call find a corresponding Gauss beam which matches with the system parameters, which will evolve into a steadystate spatial soliton and propagate steadily in the given dissipative crystal. At the same time, we have investigated the impact of diffusion on the propagation （ or solitary evolution） of the matching Gauss beam in the dissipative system. It is indicated that the diffusion effect can cause deflection of the matching Gauss beam during the transmission, and the deflection process is extremely similar to that of the corresponding DHSP soiliton. By comparing the two deflection results, we found that for the matching Gauss beam, the numerical result of deflection is close to the analytical result of the bright DHSP soliton. In a word, the solitary evolution and propagation （ including the deflection） of the matching Gauss beam is quite close to those of the DHSP in the dissipative system. So the matching Gauss beam can be used as the incident beam to replace the bright DHSP beam, which is more convenient in theory and experiment.