光折变“波导”诱失锁模ps激光脉冲自泵浦相位共轭

观察到失锁模５３２ｎｍｐｓ激光脉冲单独入射到掺Ｃｕ的ＫＮＳＢＮ晶体中，不能产生自泵浦相位共轭，但如果先用同波长的锁模ｐｓ激光脉冲在晶体中预制一条光折变“波导”，则可诱导失锁模激光脉冲形成自泵浦相位共轭．分别从“波导”形成和时间分辨光谱等方面研究了这一现象 关键词：     

Cu：KNSBN鸟翼式互泵浦相位共轭器的实验研究

利用Ｃｕ：ＫＮＳＢＮ实现了鸟翼式互泵浦相位共轭器，并给出一些实验现象和规律。     

Cu:KNSBN晶体中复色光自泵浦相位共轭猝灭实验及其理论解释

当用５１４.５ｎｍＡｒ^＋激光束入射到掺Ｃｕ的ＫＮＳＢＮ晶体中时，观察到典型的猫型自泵浦相位共轭，而当用５１４.５和４８８ｎｍＡｒ^＋激光束共线入射到该晶体中时，观察到自泵浦相位共轭猝灭现象．对这一现象给出了一个理论解释 关键词：     

BaTiO3晶体自泵浦相位共轭中的透射效应

从BaTiO_3晶体自泵浦相位共轭透射光束的出射角随泵浦光束入射角的变化,相位共轭透射光束在晶体中的光路,以及相位共轭透射光束的透射率随泵浦光束和晶体c轴夹角的变化等几方面研究了BaTiO_3晶体自泵浦相位共轭中的透射效应,根据实验结果肯定了自泵浦相位共轭中透射现象的存在.     

光折变晶体几何结构对自泵浦相位共轭特性影响的研究

基于Cu∶KNSBN晶体的自泵浦相位共轭实验,研究了光折变晶体的几何结构对自泵浦相位共轭特性的影响,得到在入射角不变的情况下,随着入射位置的变化相位共轭光输出有最大值,几何结构不同最大值输出对应的位置不同.并从理论上分析了晶体结构在双作用区自泵浦相位共轭机制中的作用,指出几何结构、入射位置与自泵浦光通道、耦合系数的关系及在自泵浦相位共轭效应中存在一个最佳入射光工作位置.     

Cu:KNSBN晶体自泵浦与互泵浦相位共轭共存特性的实验研究

利用Cu:KNSBN晶体,研究了在两束泵浦光对称入射的条件下,自泵浦与互泵浦相位共轭共存时相互竞争和相互影响的特性,以及共存时的相位共轭特性与两束泵浦光的入射位置、入射夹角和泵浦比之间的关系,并对自泵浦相位共轭反射率和两束泵浦光共同存在条件下的自泵浦相位共轭反射率进行了比较.     

Cu∶KNSBN晶体自泵浦与互泵浦相位共轭共存特性的实验研究

利用Cu∶KNSBN晶体,研究了在两束泵浦光对称入射的条件下,自泵浦与互泵浦相位共轭共存时相互竞争和相互影响的特性,以及共存时的相位共轭特性与两束泵浦光的入射位置、入射夹角和泵浦比之间的关系,并对自泵浦相位共轭反射率和两束泵浦光共同存在条件下的自泵浦相位共轭反射率进行了比较.     

环形自泵浦相位共轭振荡器

本文报道由环形自泵浦相位共轭振荡器(采用 KNSBN:Ce 晶体)所产生的相位共轭波和47%的自泵浦反射率以及在这一装置中还观测到利用晶体缺陷对光的散射作用使变弱的共轭波增强,衍射光环增亮.     

陡前沿脉冲产生的受激布里渊散射稳定性研究

受激布里渊散射转换效率及相位共轭保真度的稳定性与泵浦脉冲的前沿上升时间有关，对前沿上升时间与介质声学声子寿命接近的泵浦脉冲，在泵浦能量超过受激布里渊散射阈值较多时，会造成严重的相位共轭保真度不稳定。本文针对上升前沿时间为２ｎｓ的泵浦脉冲及声学声子寿命的１ｎｓ和ＣＣｌ４介质，在泵浦脉冲前沿根部引入缓慢上升的小信号后，采用振放双池受激布里渊散射相位共轭镜，在泵浦激光能量达到５００倍受激布里渊散射阈值时     

非相干光作用下的Ce：BaTiO3自泵浦相位共轭镜特性

地Ｃｅ：ＢａＴｉＯ３晶体的自泵浦相位共竟然非相干光作用下自泵浦相位共轭反射率增强的特性进行了研究。实验是在Ｈｅ－Ｎｅ激光产生稳态自泵浦相位共轭输出后，用非相干光平行ｃ轴照射来获得这一增强特性的，当水平移动非相干光入射位置，发现有两个区域非相干光作用能使相位共轭反射率增加，本文对此进行了相应的分析和讨论。     

Ce:KNSBN晶体中超短激光脉冲二波耦合和四波混频相位共轭

脉宽为50～60ps的超短激光脉冲列在Ce:KNSBN晶体中实现二波耦合和四波混频相位共轭。环境的微振动使二波耦合和四波混频相位共轭信号变得不稳定。当泵浦光脉冲从相对于探测光脉冲早到变为迟到时,二波耦合探测光信号从缩小变到放大。四波混频相位共轭信号出现双脉冲。晶体中存在纳秒光折变效应。     

Single-frequency operation of a broad-area laser diode by injection locking of a complex spatial mode via a double phase conjugate mirror

We demonstrate what is believed to be the first phase-coherent locking of a high-power broad-area diode to a single-frequency master laser. We use photorefractive double phase conjugation to lock the diode in a self-optimized complex spatial mode while the photorefractive crystal diffracts that complex mode in a near-diffraction-limited beam.     

Optical Associative Memory Based on Double Phase Conjugation Using Bi_（12）TiO_（20） Photorefractive Fi

ＯｐｔｉｃａｌＡｓｓｏｃｉａｔｉｖｅＭｅｍｏｒｙＢａｓｅｄｏｎＤｏｕｂｌｅＰｈａｓｅＣｏｎｊｕｇａｔｉｏｎＵｓｉｎｇＢｉ＿（１２）ＴｉＯ＿（２０）ＰｈｏｔｏｒｅｆｒａｃｔｉｖｅＦｉｂｅｒ￥ＬＩＵＳｈｕｔｉａｎ（ＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓ，...     

Double signal phase conjugation with a Cat conjugator

The phase conjugate reflection of double signals, induced by the self-pumped phase conjugation, is demonstrated in a 16° cut Cu-doped potassium sodium strontium barium niobate (KNSBN) photorefractive crystal. The phase conjugate reflectivities of signals were measured versus the pump-signal beam ratio. A comparison was made between the signal's reflectivity with and without the presence of the other signal beam. The multi-region four-wave mixing model within the same crystal has been employed to explain the geometry performance and the experimental results.     

布里渊放大器中Stokes光的高增益放大

微小Stokes信号光在布里渊放大器中得到放大,当Stokes信号光强度为015mj时,增益系数达到67。Stokes光增益决定于Stokes信号光强度及放大池中泵光与Stokes光的耦合程度,小信号Stokes光将得到较大的增益,并能得到较好的相位共轭效果     

晶体几何结构及入射角度对自抽运相位共轭特性影响的研究

基于两块不同尺寸的Cu∶KNSBN晶体自抽运相位共轭实验,研究了光折变晶体的几何结构及入射角度对自抽运相位共轭特性的影响,得到在入射位置不变化的情况下,随着入射角度的变化相位共轭光输出有最大值,几何结构不同对应的最大值不同。并从理论上分析了晶体结构及入射角度在双作用区自抽运相位共轭机理中的作用,指出几何结构、入射角度与自抽运光通道、耦合系数的关系,及在自抽运相位共轭效应中存在一个最佳入射角度,这时相位共轭光输出最大。最后,对理论上的相位共轭反射率公式进行了修正。对自抽运相位共轭实际应用中,选择最佳入射角度提供了理论和实验依据。     

向列相液晶中光学相位共轭技术的研究进展

对向列相液晶中光学相位共轭技术的研究进展进行了介绍,分析总结了向列相液晶中光学相位共轭过程的机理与实验方法,并对向列相液晶中的光学相位共轭技术的应用前景进行了展望。     

Secure optical system that uses fully phase-based encryption and lithium niobate crystal as phase contrast filter for decryption

In this paper, the implementation of a secure optical system using fully phase encryption is described. A two-dimensional phase image obtained from an amplitude image is encrypted and decrypted by using a spatial light modulator working in phase mode. The fully phase encryption is achieved using double random phase encoding. The encrypted image is holographically recorded in a photorefractive crystal and is then decrypted by generating, through phase conjugation, the conjugate of the encrypted image. A lithium niobate crystal has been used as a phase contrast filter to change the decrypted phase image into an amplitude image, thus alleviating the need for alignment of the phase contrast set-up in the Fourier plane. Simulation results are provided to verify the proposed study. The mean square error between the primary image and decrypted image has been calculated to study the sensitivity of the system.     

Optical phase conjugation by resonant degenerate four-wave mixing in liquid phase medium

In this paper, frequency-doubled Nd:YAG laser's phase conjugation has been investigated experimentally using resonant degenerate four-wave mixing (DFWM). The iodine solution was used as resonant medium. In this way, the energy of the DFWM phase conjugation beam arrived at 43μJ/pulse while the total pump beam's energy reached 8mJ/pulse. The relation between the pulse energy of the DFWM phase conjugation beam and that of the pump beam was investigated. We also measured the optical field distributions of pump beam and DFWM phase conjugation beam, from which it can be noticed that the DFWM phase conjugation can improve the laser beam quality. At the same time, we observed the influence of the pump beam's disturbance on the DFWM signal.