利用反馈技术实现了环形腔光折变振荡器的时空混沌控制。数值计算结果表明,定值反馈和变量反馈技术均可实现时空混沌控制。在振荡器系统参数确定的条件下，利用定值反馈实现了对时空混沌的控制，同时系统存在反馈系数的最小值和反馈光强度的最大值。反馈技术不仅可以实现一维的时空混沌控制，还可以实现二维的控制，而且两者控制结果相似。

Different from the cases discussed preciously, nonlinear changes of refractive index in the photorefractive materials are influenced by both the linear and quadratic electro-optic effect simultaneously now. Here we present the evolution equations of one-dimension incoherently coupled spatial soliton families due to two-photon effect in biased photorefractive crystals with both the linear and quadratic electro-optic effect and discuss their existence conditions and properties in detail. Our analysis indicates that these soliton families can exist in all three possible realizations: dark-dark, bright-bright and dark-bright provided that the incident beams have the same polarization, wavelength and are mutually incoherent. Finally, the stabilities of these soliton families have been discussed by means of beam propagation methods.

We investigate the nonvolatile holographic storage characteristics of near-stoichiometric LiNbO3:Fe:Mn crystals with different Li2O contents. Experimental results indicate that the optimal value of Li2O content is about 49.6 mol%. Nonvolatile sensitivity S′ considerably improved to 0.15 cm/J because of the use of near-stoichiometric LiNbO3:Fe:Mn with 49.6 mol% Li2O.

The influence of diffusive nonlinearity on mobility of photovoltaic lattice solitons is demonstrated. The dynamical evolution of collision between photovoltaic lattice solitons and nonlinear lattices are simulated numerically. The results show the lattice solitons with a transverse velocity have complicated behaviors and will not propagate with an oblique trajectory. When considering the diffusive nonlinearity, we find that diffusive nonlinearity can introduce a nonlinear chirped phase to lattice soliton and the lattice soliton with a special incident angle can become a "tilted soliton".

基于光折变LiNbO3晶体中体光栅的各向异性衍射特性,从理论上分析了利用单个体光栅实现波分解复用技术的方案。在此方案中,采用He-Ne 激光束记录一个特定波数的光折变体光栅,就能够实现远程通信波长在1550 nm附近的波长解复用,理论上可以实现的解复用波段范围是从1400 nm到1650 nm。由于采用了各向异性衍射,衍射光和读取光的偏振方向互相正交,提高了信噪比; 另外,方案中仅需记录单个光栅就可以实现波分复用,克服了多重光栅复用方案中记录时间复杂性的问题。

The (2+1)-dimensional nonlinear Schrodinger (NLS) equation with spatially inhomogeneous nonlinearities is investigated, which describes propagation of light in (2+1)-dimensional nonlinear optical media with inhomogeneous nonlinearities. New types of optical modes and nonlinear effects in optical media are presented numerically. The results reveal that the regular split of beam can be obtained in (2+1)-dimensional nonlinear optical media with inhomogeneous nonlinearities, by adjusting the guiding parameter. Furthermore, the stability of beam regular split is discussed numerically, and the results reveal that the beam regular split is stable to the finite initial perturbations.

对光折变全息记录特别是双中心全息记录中90°记录结构下较低的衍射效率进行了研究, 采用局域衍射理论对90°记录结构的衍射进行了分析,表明在同样的折射率变化和2 mm的光束宽度的情况下, 只有当折射率光栅振幅大于10-4时, 90°记录结构衍射效率才能够与小角度透射记录结构的衍射效率大致相当。针对环境干扰导致的干涉条纹振动影响光栅记录, 提出了有效调制度概念, 根据分析90°记录结构的干涉条纹间距很小, 容易受外界环境干扰而导致低的折射率变化率, 因此应采用主动条纹锁定系统。此外在双中心全息记录中, 微观光学参量的优化对衍射效率影响也很重要。