Generation of phase-conjugate wave and image strage by dye-doped polymer films

实验研究了曙红Y和曙红B掺杂的明胶或聚乙烯醇（PVA）薄膜简并四波混频产生相位共轭波的情况。本研究的结果如下。(1)对于染料掺杂的聚合物膜保持产生PC波所需的时间，当相同染料掺杂在PVA和明胶膜中时，PVA膜显示出与明胶膜相比约10倍的改善。该结果表明，通过适当选择聚合物膜，可以改善染料对光的耐久性。(2)曙红Y或赤藓红B掺杂的聚合物薄膜可以同时通过响应时间快的饱和吸收过程和具有记录特性的全息过程产生PC波。利用旋转反射镜周期性地改变探测波的相位，抑制全息分量的增长，从而分离出可饱和吸收分量。实验结果表明，饱和吸收分量随时间呈指数衰减。(3)根据总光子晶体信号、可饱和吸收和全息分量三个实验数据计算了两个分量之间的相位差。很明显，可饱和吸收和全息组件之间的相长或相消干涉导致总PC信号的强度波动，这取决于两个组件之间的相位差。

Generation of phase-conjugate (PC) wave by eosin Y or erythmsin B-doped gelatin or polyvinyl alcohol(PVA) films using degenerate four-wave mixing was experimentally investigated. The results of this study are as follows.(1) In respect to the time required for dye-doped polymer films to keep generating a PC wave, PVA film showed about tenfold improvement as compared to gelatin film when the same dye was doped in PVA and gelatin films, This result suggests that the durability of dye against light can be improved by a proper selection of polymer film.(2) Eosin Y or erythrosin B-doped polymer films can generate PC waves simultaneously by saturable absorption process with a fast response time and holographic process with a recording property. The saturable absorption component was separated by changing periodically a phase of probe wave with raving mirror and suppressing the growth of the holographic component. It was revealed from this experiment that the saturable absorption component decreased exponentially as the time proceeded.(3) The phase difference between two components was calculated from three experimental data: total PC signal, the saturable absorption and the holographic components. It became clear that the constructive or destructive interference between the saturable absorption and the holographic components resulted in the intensity fluctuation in total PC signal, depending on the phase difference between two components.