Linear and Nonlinear Optical Characterization of PolyDCHD-HS Films

Waveguiding films of the highly soluble polycarbazolydiacetylene polyDCHD-HS were prepared by spin coating and characterized at different wavelengths: 5 dB/cm propagation losses were observed at 1321 nm.Measurements of the third order nonliearity at 1064nm with the surface plasmon resonance method gave the valueχ(3)= i4.4×10-17+3.5×10-18 m2/V2.     

烷氧基取代聚对苯乙炔三阶非线性光学性能

通过双醚化反应、氯甲基化反应以及在强碱性条件下进行的脱氯化氢反应制备聚（2-甲氧基-5-丁氧基）对苯乙炔（PMOBOPV）、聚（2-甲氧基-5-己氧基）对苯乙炔（PMOHOPV）、聚（2,5-二丁氧基）对苯乙炔（PDBOPV）和聚（2,5-二己氧基）对苯乙炔（PDHOPV）等四种可溶性聚对苯乙炔（PPV）衍生物,通过紫外-可见吸收光谱对产物分子结构进行表征.结果显示,PMOBOPV、PMOHOPV、PDBOPV和PDHOPV的共轭π电子发生π → π* 跃迁的吸收峰分别位于491 nm、495nm、504nm和510nm处,相应的光学禁带宽度分别为2.23eV、2.18eV、2.12eV和2.07eV.利用简并四波混频技术测量PPV衍生物的三阶非线性光学性能,探讨了分子结构对PPV衍生物三阶非线性极化率（χ(3)）的影响.研究发现,激发波长为532 nm时,PMOBOPV、PMOHOPV、PDBOPV和PDHOPV的共振χ(3)值分别为3.45×10－10、5.13×10－10、7.15×10－10和9.61×10－10 esu;激发波长为1064 nm时,它们的非共振χ(3)值分别为1.09×10－11、1.42×10－11、1.62×10－11和2.14×10－11 esu.     

离子注入/辐照引起Al2O3单晶的改性研究

600K温度下用110keV的He^＋,Ne^＋,Ar^＋离子注入及320K温度下用230MeV的^208Pb^27＋辐照Al2O3单晶样品,研究了离子注入和辐照对Al2O3单晶样品结构和光学特性的影响。从测得的光致发光谱可以清楚地看到,所有样品在波长为375,413和450nm处出现了强的发光峰。且所有5×10^16ion／cm^2注入样品的发光峰均最强。经过高能Pb辐照后的样品,在390nm处出现了新的发光峰。透射电镜分析发现在注入氖样品100nm入射深度以内形成了高浓度的小空洞（1-2nm）,在Ne沉积区域有少量大空洞形成。傅立叶变换红外光谱分析发现,波数在460-510cm^-1间的振动吸收带经过离子辐照后展宽,随着辐照量的增大,该振动吸收强度显著减弱。1000—1300cm^-1对应Al-O-Al桥氧伸缩振动模式的吸收带,辐照后向高波数方向移动。对离子注入和辐照对Al2O3单晶样品结构损伤机理进行了初步探讨。Single crystal sapphire （Al2O3 ） samples were implanted at 600 K by He, Ne and Ar ions with energy of 110 keV to doses ranging from 5 × 10^16 to 2× 10^17 ion/cm^2 or irradiated at 320 K by ^208Pb^27＋ ion with energy of 1.1 MeV/u to the fluences ranging from 1 × 10^12 to 5 × 10^14 ion/cm^2. The modification of structure and optical properties induced by ion implantation or irradiation were analyzed by using photoluminescence（PL） and Fourier transformation infrared spectrum（FIR） spectra and transmission electron microscopy（ TEM ） measurements. The PL measurements showed that absorption peaks located at 375,413 and 450 nm appeared in all the implanted or irradiated samples, the PL intensities reached up to the maximum for the 5 × 10^16 ion/cm^2 implanted samples. After Pb-ion irradiation, a new peak located at 390 nm formed. TEM analyses showed that small size voids,（ 1--2 nm） with high density were formed in the region from the surface till to about 100 nm in depth and also large size Nebubble formed in the Ne-doped region. From the obtained FTIR spectra, it was found that Pb-ion irradiation induced broadening of the absorption band in 460-510 cm^-1 and position shift of the absorption band in 1 000- 1 300 cm^- 1 towards to high wavenumber. The possible damage mechanism in single crystal sapphire induced by energetic ion implantation or irradiation was briefly discussed.     

Spectroscopic properties of thulium ions in bismuth silicate glass

A new type of bismuth silicate glass (Bi2O3-SiO2-ZnO-Al2O3-La2O3) doped with Tm2O3 is prepared by melt-quenching method. The thermal stability of the glass is examined by differential scanning calorimetry. No crystallization peak is found. Using the absorption and emission spectra, the absorption and emission cross-sections are calculated. Their maximum data are 2.9×10-21cm2 at 1663 nm and 4.7×10-21cm2 at 1826 nm, respectively. Using the Judd-Ofelt theory, the radiation transition probabilities and radiative lifetimes are obtained. The extended overlap integral method is applied to analyze energy transfer process among the Tm3+ ions. The transfer constants of cross-relaxation and energy migration among the Tm3+ ions at the 3H4 level are 7.60×10-40 and 14.98×10-40 cm6 /s, respectively. The critical transfer radius for cross-relaxation is 0.99 nm. The cross relaxation process is easy to realize and is favorable for obtaining ～2-μm laser.     

八元瓜环诱导菲、芴的室温磷光研究

以八元瓜环为诱导剂、碘化钾作重原子微扰剂,在亚硫酸钠除氧下,实现了菲、芴的室温磷光发射。在该体系中菲、芴的最大激发和发射波长分别为282和509 nm,276和518 nm,磷光寿命分别为1.82和3.68 ms。在最佳实验条件下,菲在1.0×10-7～1.5×10-6mol·L-1,1.5×10-6～1.0×10-5 mol·L-1和芴在8.0×10-7～8.0×10-6mol·L-1的浓度范围内分别与其磷光强度呈良好的线性关系,检出限分别为4.8×10-9和8.0×10-9 mol·L-1。     

Narrowband ultraviolet photodetector based on MgZnO and NPB heterojunction

An ultraviolet photodetector was fabricated based on Mg_0.07Zn_0.93O heterojunction. N, N'-bis (naphthalen-1-y1)-N, N'-bis(pheny) benzidine was selected as the hole transporting layer. I-V characteristic curves of the device were measured in the dark and under the illumination of 340?nm UV light with density of 1.33 mW/cm². The device showed a low dark current of about 3×10^-10 A and a high photo-dark current ratio of 1×10⁵ at -2 V bias. A narrowband photoresponse was observed from 300 to 400?nm and centered at 340?nm with a full width at half-maximum of only 30?nm. The maximum peak response is at 340?nm, which is 0.192 A/W at the bias of -1 V.     

硫杂杯[4]荧光探针的离子识别及分子逻辑门研究

以硫杂杯[4]芳烃为母体,在其1,3-位连接羟乙基邻苯二甲酰亚胺,2,4-位以三氮唑为连接基,将苄基引入硫杂杯[4]芳烃的下沿,得到硫杂杯[4]-邻苯二甲酰亚胺衍生物荧光探针(s1)。探针s1发射强烈荧光,在CH₃CN介质中的相对荧光量子产率为0.43。在DMF/H₂O介质中,以310 nm为激发波长,Fe3+能选择性猝灭探针s1在390 nm处的荧光;在CH₃CN介质中,以245 nm为激发波长,I-能选择性猝灭探针s1在310 nm处的荧光,光谱滴定和等温滴定量热均测出探针s1与Fe3+或与I-形成1∶1配合物,结合常数均达105。结合自由能表明配合为自发过程。荧光猝灭检测Fe3+和 I-的浓度线性范围分别为1.0×10-7～1.6×10-4 mol·L-1和1.0×10-7～8.5×10-5 mol·L-1,检测限分别为2.30×10-8 mol·L-1和1.17×10-8 mol·L-1。同时,利用识别和竞争配合作用,控制Fe3+和F-的输入使探针s1发射荧光或荧光猝灭,构建了分子水平上的逻辑电路。红外光谱推测探针s1分子中三氮唑基的氮原子参与了识别Fe3+的配位,而探针s1分子中三氮唑环上的芳氢与I-形成氢键而实现识别。     

荧光光谱法检测中药茯苓中的异丙威

利用分子荧光光谱,对异丙威溶液用三维荧光方法进行检测,建立了用异丙威的256nm/290nm荧光峰进行检测的实验方法。结果表明,该方法在高浓度和低浓度都具有较好的稳定性,在9.75×10-3—4.875×10-2mg/mL范围内线性相关系数为0.9970;在1.95×10-5—1.95×10-4mg/mL范围内线性相关系数为0.9955;且具有重现性好,检出限低,方法快速等优点。     

掺铒碲-钨-钠玻璃基质的光谱性质研究

制备了用于离子交换法制备光波导器件的掺铒碲-钨-钠玻璃基质。应用扎得-奥菲而特(Judd—Ofelt)理论计算了玻璃样品的三个强度参量,由强度参量计算了Er^3 离子的自发跃迁几率、荧光分支比等光谱参量;应用麦克库玻(McCumber)理论,计算了Er^3 离子在1．5μm的受激发射截面,荧光测试发现Er^3 离子的荧光半峰全宽可达65nm。比较了Er^3 离子在不同玻璃基质中的光谱特性。结果表明,Er^3 离子在碲-钨-钠玻璃中具有较高的受激发射截面和较宽的荧光半峰全宽,可以用于宽带光波导器件的制备。     

温度和应变对光纤折射率的影响

采用迈克尔逊（Ｍｉｃｈｅｌｓｏｎ）光纤白光干涉系统，通过测量随着温度或应变改变而变化的光程，给出了单模光纤有效折射率的温度和应变相关特性。对于ＳＭＦ－２８型单模光纤，测得折射率温度系数和应变温度系数在波长为１３００ｎｍ处分别为０．７６２×１０－５／℃及－０．１３３２×１０－６／με；在波长１５５０ｎｍ处则为０．８１１×１０－５／℃及－０．１６４９×１０－６／με。并与几种不同光纤相应的数据进行了比较。     

Measurement of the third order nonlinear optical coefficients of GaP and chirp parameter of laser pulse

The spectral resolved femtosecond pump-probe experiment is applied to measure the third order nonlinear refractive index coefficient, two-photon absorption coefficient of GaP crystal, and the chirp parameter of the input laser pulses. The results show that nonlinear refractive index coefficient is 2× 10-18 m2/W, twophoton absorption coefficient is 2× 10-11 m/W at wavelength of 783.5 nm, and the chirp parameter of laser pulse is l× 1025 s-2. Furthermore, the mechanism of nonlinear refraction due to two-photon absorption in GaP crystal and experimental results are discussed.     

聚合物薄膜电光效应研究

介绍聚合物DR/PMMA薄膜材料做成光学法布里-珀罗腔结构,通过观察透射率随外加电场变化,以确定其非线性光学特性参量,在室温和575.0nm时的三阶极化率x~⑶(-ω;ω,0,0)=(5.3-i6.0)×10~((-11)_(θs.u))和二次电光系数R=-(8.5-i9.7)×10~(-19)m~2/V~2.     

环丙沙星荧光光度法测定微量铝(Ⅲ)

在HAc-NaAc缓冲介质中,铝(Ⅲ)对环丙沙星有荧光增强作用,据此建立了测定微量铝的荧光分析法。选择最大激发与发射波长分别为273nm和439nm,在pH=4.00的HAc-NaAc缓冲溶液介质中,环丙沙星的荧光强度变化与铝(Ⅲ)浓度呈良好的线性关系,线性范围为1.05×10-4—7.35×10-2mol/L,方法的检出限为5.6×10-6mol/L,校准曲线回归方程式为F/F0=0.272lgC+2.764。本方法用于实际样品中铝(Ⅲ)的测定,结果满意。     

碳量子点/曙红Y比率型荧光探针测定L-抗坏血酸

以天然生物质去皮的蓖麻为碳源,采用一步水热法合成了荧光性能优良的绿色荧光蓖麻碳量子点(CO-CQDs),对其形貌和发光性能进行了表征。通过将该CO-CQDs与荧光极强的卤代荧光素染料曙红Y(EY)复合,二者可形成荧光发射峰相距较远的新型CO-CQDs/EY复合物。在pH=4.00的Na2HPO4-柠檬酸缓冲溶液中,在320 nm的激发波长下,CO-CQDs/EY复合物于405 nm和540 nm处显示出两个独立的荧光发射峰。在该体系中加入Cr(Ⅵ),405 nm和540 nm两处的荧光信号均显著猝灭。L-抗坏血酸(L-ascorbic acid,AA)的加入可使复合物于540 nm的荧光信号恢复,而405 nm处的荧光强度基本不变。据此建立了一种以CO-CQDs/EY复合物为比率型荧光探针测定AA的新方法。实验测定了荧光信号恢复的最佳条件和影响荧光恢复的因素,初步探讨了反应机理。在优化的实验条件下,该探针于540 nm/405 nm两处的荧光强度比值与AA的浓度在5.0×10^-8~4.0×10^-6 mol/L范围内呈良好线性关系,检出限为3.7×10^-8 mol/L。该探针用于检测药物、水果和蔬菜中AA的含量,结果满意。     

免受温度影响的光纤光栅位移传感器

将一定长度、均匀周期的光纤光栅沿轴向刚性粘贴于厚度呈阶跃分布的等腰三角状悬臂梁界线附近的表面上 ,通过观测该光栅反射谱中两个峰值的间距来监测梁自由端在垂直于表面方向上的位移。实验表明该无源温漂位移线性传感装置的传感灵敏度达 9.2 4× 10 -2 nm/ mm,与理论值 9.4× 10 -2 nm/ mm非常接近。     

宽带腔增强吸收光谱技术应用于痕量气体探测及气溶胶消光系数测量

基于氙灯的非相干宽带腔增强吸收光谱系统, 并将其应用于痕量气体及气溶胶消光系数的测量. 该系统的探测灵敏度通过测量NO₂在520—560 nm波长范围内的吸收得到验证, 最小可探测灵敏度为1.8× 10^-7cm^-1 (1σ, 0.12 s积分时间, 50次平均), 对应的NO₂探测极限～33 nmol/mol. 结合标准气溶胶粒子发生系统, 测量了不同浓度的单分散硫酸铵气溶胶粒子在532 nm波长处的消光系数, 得到粒径为600 nm的硫酸铵气溶胶的消光截面为1.12× 10^-8cm², 与文献报道值1.167× 10^-8cm²相一致, 验证了气溶胶测量的可行性和准确性.     

GeV能量的Fe离子在C60薄膜中的辐照效应研究

利用傅立叶转换红外光谱和Raman谱仪分析了0.98 GeV的Fe离子在电子能损Se为3.5 keV/nm时， 不同辐照剂量（5×1010 —8×1013 ions/cm2)下， 在C60薄膜中引起的辐照损伤效应。 分析表明， Fe离子辐照引起了C60分子的聚合与损伤。 在辐照剂量达到一中间值1×1012 ions/cm2， C60分子的损伤得到部分恢复， 归因于电子激发引起的退火效应。 通过对Raman数据的拟合分析， 演绎出Fe离子辐照在C60材料中形成的潜径迹截面或引起损伤的截面约为1.32×10-14 cm2。     

High response organic deep ultraviolet photodetector with PEDOT:PSS anode

We have fabricated an organic deep ultraviolet photodetector (PD) using PEDOT:PSS (PH 1000) as a transparent anode. NPB and PBD were employed as electron donor and acceptor, respectively. The PD exhibits a dark current of 0.0829 μA/cm(2) and a photocurrent of 85.3 μA/cm(2) at -12 V under 280 nm light illumination with an intensity of 0.488 mW/cm(2). A high response at 248-370 nm with its peak of 0.18 A/W at 280 nm and a detectivity of 1.1×10(12) cm Hz(1/2) W(-1) were achieved. The more detailed mechanism of harvesting high performance and the dependence of photocurrent density on illumination intensity are also discussed.     

飞秒激光-薄膜靶相互作用中超热电子产额和激光转化效率

 在激光能量130 mJ（靶面），脉宽60 fs，波长800 nm，对比度1∶10^-6，激光与靶法线成45°夹角，P偏振，靶面激光峰值功率密度约为7.0×10¹⁷ W·cm^-2，无预脉冲的条件下，采用电子谱仪与经γ标准源标定的LiF热释光探测器（TLD）相配合，测量了飞秒激光-薄膜靶相互作用中产生的超热电子能谱。根据所测的能谱，推算出超热电子的产额和激光能量转化为超热电子能量的效率，在靶法线方向分别为1.19×10¹⁰/sr和4.55%/sr，在激光反射方向分别为1.83×10⁹/sr和0.76%/sr。结果显示，不同方向的超热电子产额和激光转化效率有所不同，原因在于激光-等离子体相互作用产生的超热电子构成各向异性的分布。     

Laser-Induced Current Switching Observed in the Discharge Media of CF2Cl2-N2 and CH3Cl-N2

Switchings of discharge current induced by ArF and KrF laser pulses in the discharge media of CF2Cl2-N2 and CH3Cl-N2 were investigated using a negative point-to-plane discharge apparatus. The electron attachment rate constants of CF2Cl2 in buffer gases of N2 and Ar were measured by a parallel-plate drift-tube apparatus at various E/N, from which the dominant negative ions in the discharge media were inferred. The conductivity of the discharge medium is enhanced upon laser irradiation due to conduction electrons being produced from photoelectron-detachment of Cl-. From the dependence of the enhanced current on laser power, the photodetachment cross sections of Cl- in a given discharge condition were derived to be 2.5 × 10-17 cm2 at 193 nm and 1.0 × 10-17 cm2 at 248 nm. After the current enhancement, the current was greatly reduced as was observed in the discharge medium of CF2Cl2-N2, but not in CH3Cl-N2. The mechanism for the optically induced reduction of discharge current is discussed.