We propose and experimentally investigate a new scheme capable of suppressing the light-induced scattering by periodical incoherent erasure during every non-volatile holographic recording cycle in photochromic LiNbO_(...We propose and experimentally investigate a new scheme capable of suppressing the light-induced scattering by periodical incoherent erasure during every non-volatile holographic recording cycle in photochromic LiNbO_(3):Fe:Mn crystals.The results demonstrate that the scattering noise is suppressed effectively,and the final diffraction efficiency of the fixed grating is significantly enhanced,rather than decrease,by about 30%compared with the conventional recording procedure.The period of the recording and incoherent erasure cycle is theoretically calculated and experimentally optimized.展开更多
The Kukhtarev two-center model for photochromic doubly doped LiNbO_(3):Fe:Mn crystals is both numerically and analytically solved for the recording sensitivity and the fixed nonvolatile space-charge field.An optimal p...The Kukhtarev two-center model for photochromic doubly doped LiNbO_(3):Fe:Mn crystals is both numerically and analytically solved for the recording sensitivity and the fixed nonvolatile space-charge field.An optimal prescription for material doping and oxidation/reduction processing is found,which requires that the crystal should be strongly oxidized together with a suitable Mn density with respect to the Fe density.Experiments performed with an oxidized crystal and a reduced crystal prove the prediction.展开更多
The design and fabrication of an optical 2×490°hybrid based on birefringent crystals for a coherent receiver in a free−space optical communication system are presented.For the quadrature receiver,two pairs o...The design and fabrication of an optical 2×490°hybrid based on birefringent crystals for a coherent receiver in a free−space optical communication system are presented.For the quadrature receiver,two pairs of 180°phase−shift outputs are obtained and one pair has a phase difference of 90°with respect to the other.The 90°hybrid comprises two pairs of stacked birefringent plates,a phase retardation plate and an analyser birefringent plate.The testing results measured by the heterodyne method verify that the 2×4 optical 90°hybrid can work correctly and effectively.The phase compensation and further optimization schemes are also proposed.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.69837020the Chinese Academy of Sciences。
文摘We propose and experimentally investigate a new scheme capable of suppressing the light-induced scattering by periodical incoherent erasure during every non-volatile holographic recording cycle in photochromic LiNbO_(3):Fe:Mn crystals.The results demonstrate that the scattering noise is suppressed effectively,and the final diffraction efficiency of the fixed grating is significantly enhanced,rather than decrease,by about 30%compared with the conventional recording procedure.The period of the recording and incoherent erasure cycle is theoretically calculated and experimentally optimized.
基金Supported by the National Natural Science Foundation of China under Grant No.69837020,and the Hundred Talents Program of Chinese Academy of Sciences.
文摘The Kukhtarev two-center model for photochromic doubly doped LiNbO_(3):Fe:Mn crystals is both numerically and analytically solved for the recording sensitivity and the fixed nonvolatile space-charge field.An optimal prescription for material doping and oxidation/reduction processing is found,which requires that the crystal should be strongly oxidized together with a suitable Mn density with respect to the Fe density.Experiments performed with an oxidized crystal and a reduced crystal prove the prediction.
基金by the Chinese Academy of Sciences,the National Natural Science Foundation of China under Grant No 60908029the Natural Science Foundation of Shanghai under Grant No 09ZR1435300the National High-Tech Research and Development Program of China under Grant No 2007AA01Z298.
文摘The design and fabrication of an optical 2×490°hybrid based on birefringent crystals for a coherent receiver in a free−space optical communication system are presented.For the quadrature receiver,two pairs of 180°phase−shift outputs are obtained and one pair has a phase difference of 90°with respect to the other.The 90°hybrid comprises two pairs of stacked birefringent plates,a phase retardation plate and an analyser birefringent plate.The testing results measured by the heterodyne method verify that the 2×4 optical 90°hybrid can work correctly and effectively.The phase compensation and further optimization schemes are also proposed.
