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

实验研究了掺杂伊红Y或红霉素b的明胶或聚乙烯醇（PVA）薄膜用简并四波混合产生相共轭（PC）波。本研究的结果如下：(1)在掺杂相同染料的聚合物薄膜中，PVA薄膜比明胶薄膜持续产生PC波所需的时间提高了约10倍，这表明通过选择适当的聚合物薄膜可以提高染料的耐光性。(2) Eosin Y或红素b掺杂聚合物薄膜可以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同时产生PC波。利用衍射镜周期性地改变探测波的相位，抑制全息组分的生长，分离出饱和吸收组分。实验结果表明，随着时间的延长，饱和吸收成分呈指数递减。(3)利用总PC信号、可饱和吸收和全息分量三个实验数据计算两分量的相位差。很明显，饱和吸收和全息分量之间的相消干涉会导致总PC信号的强度波动，这取决于两个分量之间的相位差。

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.