组合外加电场提高Fe：LiNbO3中90°记录体全息的衍射效率

针对90°全息记录结构的特殊性，在记录和读出阶段分别施加不同极性的外加电场，实现了Fe：LiNbO3晶体中高衍射效率的全息记录和读出。在库赫塔列夫（Kukhtarev）方程基础上引人两维耦合波理论，对组合外加电场提高掺铁铌酸锂晶体光折变特性的机理进行了探讨。实验和理论计算结果都表明这种分别在记录和读出过程施加不同极性组合的外加电场是在Fe：LiNbO3中实现高衍射效率90°记录结构体全息的有效技术方案。

Significant improvements of photorefractive properties such as diffraction efficiency with 90° holographic recording geometry have been obtained by the application of external electric fields with different directions during recording and readout phase. Based on the vectorial Kukhtarev equations and two-dimensional coupled wave theory, the theoretical analysis are given to investigate the photorefractive properties of Fe-doped LiNbO3 crystals when the external electric field is applied. Experimental and theoretical results show that the application of combined external electric field is an effective and useful optimal scheme for the enhancement of diffraction efficiency with 90° recording geometry.