偶氮染料掺杂PVA的全光开关特性研究

光开关是光通信、光计算机、光信息处理等领域的重要光学元件。利用半导体激光(473nm)作为泵浦光,He-Ne激光(632.8nm)作为探测光,实验研究了偶氮染料掺杂PVA薄膜材料光致双折射效应信号的生长、擦除、衰减特性,分析了泵浦光偏振方向与探测光偏振方向夹角、泵浦光功率对光致双折射效应和全光开关特性的影响,探讨了该材料在光开关方面的应用前景。     

偶氮苯液晶薄膜相位共轭的光学记录研究

利用间并四波混频研究了一种偶氮苯液昌聚合物的相位共轭和光学记录特性，在近共振条件下，用低功率Ｎｄ：ＹＡＧ倍频激光得到高效率的相位共轭光和高阶衍射光，当光强达到１０Ｗ／ｃｍ＾２量级时，薄膜显示出光记录效应，即在撒掉写入光之后，相位共轭波并不消失，进一步大光强到１０＾３Ｗ／ｃｍ＾２量级时，出现三组分别只与前向泵浦光，后向泵浦光和信号有关的高阶衍射光。其中观察到第三阶衍射光，且在撒掉任两束光后，所剩一束     

Optical Recording Performance of Azo Nickel Chelate Thin Film

The absorption,transmission and reflection spectra of spin-coated films of Ni(azo)2 (azo nickel chelate) were measured. Because of the intermolecular aggregation,the absorption peak of Ni(azo)2 thin film has a red-shift of about 40 nm with respect to that of it in methanol solution. The fabricated optical disk showed a reflectivity of 48% and its carrier-noise ratio (CNR) was greater than 45 dB when recording with 7.5 mW laser power at the wavelength of 780 nm.     

Optical Recording Performance of Azo Nickel Chelate Thin Film

1IntroduCtionAndyeshavebeenwidelystudiedasmaterialsforreverwhleoPticalstorae,forholographasanexamPle,inwhichisomerizatiOnofazomoeculesekistSbetWeentransandcisform['~'].HOWever,therearetwomainproblemswhichhavelindtedtheirfurtherpracticalaPplications.oneisthatthesbetransformationspeedbetweenisomers,vawingfroInseveralhacrosecondstoseveralseconds,can'tmeetthehighspeeddemandofdatastorage.Theotheristhattheunstablecisstateofazodyesthermallyre-isomerizestothemorestabletransisomerverycommnly.Aithou…     

酞菁铜薄膜的光记录特性

研究了有机染料酞菁铜（ＣｕＰｃ）真空蒸镀薄膜在可见及近红外区域的吸收光谱和光学常数，发现酞菁铜薄膜在５５０－７５０ｎｍ波长范围内具有较强的吸收，在静态测试仪上测试了酞菁铜薄膜的光存储记录特性，发现用低功率氦氖激光照样品时薄膜反射率变化较大，在酞菁记录层上覆盖金属反射层将提高写入激光的阈值能量并且增大反射率的对比度。     

偶氮染料掺杂高分子PMMA薄膜的光学参数

在单晶硅片上,利用旋涂法,制备了偶氮染料掺杂高分子（ＰＭＭＡ）薄膜,可变入射角、波长扫描的全自动椭圆偏振光谱仪,研究了薄膜的复折射率、吸收系数和厚度,分析了影响薄膜电子光谱的因素。研究结果表明,该薄膜在４００～６００ｎｍ波长范围内,存在强而宽的吸收,并且发现分子聚集状态对该染料的吸收光谱有较大的影响。     

偶氮基染料掺杂薄膜的双光子图象存储

研究了偶氮基染料掺杂薄膜ＭＯ－ＰＶＡ和ＥＯ－ＰＶＡ的双光子存储特性。在对薄膜用Ａｒ＾＋激光作预激发下实现了Ｈｅ－Ｎｅ激光的红光存储。获得了实时和短时存储照片。光电记录存储曲线，分析了双光四能级系统的存储机制。实现确定了最佳预激发功率约为０．２８Ｗ／ｃｍ＾２，最小Ｈｅ－Ｎｅ光可存储功率密度低于０．２Ｗ／ｃｍ＾２。     

利用全息法在偶氮聚合物薄膜中记录涡旋光场

利用全息技术在偶氮聚合物薄膜中记录了拓扑荷数q=–1,1,2,4的涡旋光场,并将记录的原始叉形光栅与计算全息光栅进行对比,对不同拓扑荷数涡旋光的记录速率和偶氮材料的可重复擦写性能进行了测试;记录完成后,将复现涡旋光与高斯光束干涉,并与原始涡旋光和原始叉形光栅对比,分析了记录质量.实验结果表明:高阶涡旋光场的全息叉形光栅...     

全光极化聚合物薄膜中染料分子取向的模型

对光极化后偶氮染料聚合物薄膜中染料分子的取向方式进行了研究,指出当写入光（基频与其倍频光）为线偏振且偏振方向互相平行时,极化薄膜中多数染料分子垂直写入光偏振的方向作轴向排列,而少数分子沿平行于写入光偏振的方向作极性排列,但只有后者对薄膜的宏观二阶非线性有贡献,实验证实了上述模型。     

SA/PMMA的可擦除光存储特性研究

用在聚甲基丙烯酸甲脂（PMMA）中掺杂邻羟基亚甲基苯胺（SA）样品，实现了可见光区域的可擦除光存储。以Ar^ 激光488.0nm线为写入光，He-Ne激光632.8nm线为读出光，研究了光栅生长的动力学过程。在写入和擦除过程中，均观察到了衍射信号随时间先增强后减弱的趋势。探讨了写入光和擦除光功率对衍射信号的影响，依据相干光调制形成相位光栅和光异构产生压力梯度引起分子扩散的光物理过程对光存储机制进行了探讨。     

一种菁染料－聚合物薄膜的光存存储性能

用旋涂法制备了一种菁染料－聚合物薄膜，并研究了该染料－聚合物薄膜的光谱性质和光存储性能。该染料薄膜在６６０～８３０ｎｍ波段有较强的吸收和２０％以上的反射率。在最佳实验条件下，获得了５８ｄＢ的信噪比。信噪比（ＣＮＲ）、载波信号强度（Ｃ）和薄膜反射率变化（ΔＲ）的对数（ｌｇΔＲ）成正比     

双色俘精酸酐薄膜的双波长图像光存储

采用两种光致变色俘精酸酐体系化合物[1,2,4-三甲基-5-苯基-3-吡咯甲叉(异丙叉)俘精酸酐和对-N,N-二甲基苯基-2-甲基-3-恶唑甲叉(异丙叉)俘精酸酐]制备了单层双色聚甲基丙烯酸甲酯(PMMA)复合薄膜感光记录材料。采用双波长(650nm和488nm)图像存储和读出光路,实现了用两种波长在双色复合薄膜的同一位置同时记录两幅图像。当分别用各自对应的波长读出时,两幅图像各自获得了高衬比度,且二者之间的串扰很小,证明了在双色光致变色俘精酸酐材料上进行双波长复用图像光存储的可行性。     

AgTCNQ衍生物旋涂膜绿光可擦重写光存储性质研究

报道了新型电子转移复合物AgTCNQ脂类衍生物：银-(2,5-二丙酸甲酯-7,7,8,8-四氰基对苯醌二甲烷)的旋涂薄膜的光谱特征、薄膜的静态绿光可擦重写光存储性能,并研究了薄膜的可擦重写机理。结果表明该薄膜在388nm和675nm处有两个源于复合物中阴离子自由基TCNQ(C2H4COOCH3)2^-中的电子跃迁的特征吸收峰;AgTCNQ酯类衍生物旋涂膜具有良好的绿光光存储性能,该薄膜在写入功率为9mW,写入脉冲为80ns,擦除功率为4mW,擦除脉冲为500ns时反射率衬比度大于15％,循环次数可达100次以上,并且没有出现任何疲劳现象。机理研究表明,AgTCNQ酯类衍生物与AgTCNQ有着相同的可逆光致变色机理,即在激光作用下因复合物中可逆电子转移引起薄膜光学性质的可逆变化,从而实现可擦重写光信息存储。     

Thermally Stable and Resonance Enhanced Large Nonlinear Optical Properties In Poled Silica Films Doped with Thiazole Azo Dye

Sol-gel processed poled silica films doped with novel nonlinear organic materials, thiazole azo dye (TA), are prepared in high concentration. Resonance enhanced second-order nonlinear optical coefficient of d₃₃ = 154 pm/V is obtained from TA doped silica film (40 wt%) for the fundamental wavelength of 1064 nm. The value d₃₃ is unvaried for at least 100 h under a high temperature condition (100°C) without any relaxation. Wavelength dependent second-order nonlinearity is also measured.     

Optical Limiting and ExcitedState Nonlinear Optical Properties in Lead Phthalocyanine

1.IntroductionLeadphthalocyaninehasreceivedconsiderableattentionasitexhibitsstrongreversesaturableabsorption(RSA)behaviorLI].Thiskindoforganometalliccompoundcanbeusedasopticallimitingdevicetoprotecteyesandsensorsfromlaserhazard.Thenanosecondopticallimitingpropertyofleadphthalocyaninehasbeeninvestigatedyet[2].Inthispaper,thepicosecondopticallimitingbehaviorofleadphthalocyanine(Pbpc(CP)4)ispresentedandtheresultiscomparedwithC6o,areversesaturableabsorptionmaterialwhichhasbeenwidelystudied.The…     

新型含偶氮侧链聚合物中光致各向异性及偏振全息记录

研究了偶氮侧链聚合物中光致各向异性和偏振全息, 确认在这种聚合物中分析光致各向异性动力学过程时, 必须考虑光漂白效应的影响, 测量表明该聚合物具有大的光致双折射（Δｎ ＝７．８×１０－ ３）, 并在其中记录了高衍射效率（η＝ １９．３％ ）的偏振全息图     

Polarization-Dependent Light-Gated Phase Conjugation in Methyl-Orange Doped Polymer Film

We have investigated the polarization state of a gated phase conjugate beam using a methyl-orange doped poly-vinyl alcohol (MO/PVA) film in 16 different combinations of linear and circular polarization states of a probe beam and pump beams. The experimental results agree with the theoretical prediction based on the Jones matrix method. Of the third-order nonlinear susceptibility tensors X_ijkl of the MO/PVA film, the X₁₂₂₁ at the 647 nm wavelength in degenerate four-wave mixing under exposure of a gating 515 nm light takes a very small value compared with X₁₁₁₁ and X₁₁₂₂. On the other hand, in the configuration of a probe beam and pump beams having linearly crossed polarizations and without gating light, the MO/PVA film generates a strong linearly polarized PC beam, so that X₁₂₂₁ takes a large value at 515 nm.     

光致变色多阶光存储中的光学串扰分析

利用光致变色材料的灰度分阶特性可以实现多阶光存储。以傅里叶光学和光致变色记录符的可叠加性为基础,采用霍普金斯标量衍射理论的经典归-化坐标,对光致变色多阶光存储中的光学串扰进行了理论建模和数值分析。作为后续电通道补偿设计的前提。数值计算结果表明：相邻记录符与盘基信号的交叉串扰项是光学串扰的主要成分,且随着中心距的增加,相邻记录符引起的串扰迅速降低;当无寻道误差时,邻道记录符引起的串扰可以忽略;高阶记录符引起串扰要明显高于低阶的串扰。且影响多阶存储的可分阶性;实验结果很好地验证了所建立的模型的合理性。     

Enhancement in SERS intensities of azo dyes adsorbed on ZnO by plasma treatment

Surface‐enhanced Raman scattering (SERS) spectra of azo dyes (methyl orange and p‐methyl red) adsorbed on ZnO nanoparticles were observed. Hydrothermally synthesized ZnO nanoparticles were characterized by powder X‐ray diffraction and X‐ray photoelectron spectroscopy. The ZnO nanoparticle size, monitored with X‐ray diffraction, was tuned by calcination to optimize SERS intensities. The observed SERS effect of azo dyes adsorbed on ZnO can be ascribed to charge‐transfer resonance effect. Time‐dependent density functional theory was used to calculate the optical spectra and interpret the chemical enhancement observed in the experiment. The SERS enhancement factors for methyl red on ZnO were boosted by nearly four times and twice with O₂ plasma and H₂ plasma, respectively. However, plasma treatment showed no effect on the enhancement factors of methyl orange on ZnO. We conclude that plasma‐induced defect formation and band gap shift in ZnO and the coupling of energy levels between ZnO and azo dye molecules are responsible for the observed enhancement of SERS intensities. Copyright © 2014 John Wiley & Sons, Ltd.     

新型偶氮化合物的光致双折射及双波长图像共存研究

合成了新型偶氮分子 4 硝基 3 偶氮 9 乙基 咔唑 (ANECz) ,将其掺入聚甲基丙烯酸甲脂 (PMMA)中制成薄膜器件。实验结果表明 ,样品具有极大的光致双折射 (δn =1.8× 10 -2 )。还利用四波混频 (DFWM )技术实现了双波长光点及图像的共同存储 ,给出了相应的光电记录曲线和摄影记录 ,并分析了双波长共存中的竞争机制。