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1.
硒化铅量子点聚乙烯醇薄膜的三阶非线性光学特性   总被引:2,自引:0,他引:2  
通过湿化学方法制备了具有三阶非线性光学性质的硒化铅/聚乙烯醇复合物薄膜.采用透射电镜和扫描电镜对硒化铅量子点的尺寸和薄膜的形貌进行表征.运用Z扫描方法,研究了薄膜在波长为532nm,脉冲宽度为38ps条件下的三阶非线性光学性质.实验结果表明:合成的硒化铅量子点尺寸在10nm左右,属于强量子受限,制备的薄膜表面粗糙度比较好;薄膜在皮秒脉冲激光作用下呈现负的非线性折射效应和反饱和吸收性质,其三阶非线性极化率χ(3)为3.6×10-11 esu.  相似文献   

2.
杨光  陈正豪 《物理学报》2007,56(2):1182-1187
通过准分子激光(XeCl, 308 nm, 20 ns)在MgO(100)单晶衬底上制备了不同掺杂浓度的Ag:BaTiO3纳米复合薄膜,通过X射线衍射和X射线光电子能谱对薄膜的结构和组分进行了表征.在430 nm和470 nm附近观测到了不同浓度Ag纳米颗粒引起的等离子体吸收峰,通过z扫描技术对复合薄膜的三阶非线性光学特性进行了测量,并对其光学非线性的增强机制进行了讨论. 关键词: 金属纳米复合薄膜 激光沉积 非线性光学  相似文献   

3.
甘平  辜敏  卿胜兰  鲜晓东 《物理学报》2013,62(7):78101-078101
应用分光光度计测量Te/TeO2-SiO2复合薄膜的透射光谱和吸收光谱, 在480nm附近观察到Te颗粒引起的等离子体共振吸收峰; 采用Z扫描技术研究了共振(激发波长为532 nm)和非共振情况下(激发波长1064 nm) 不同电位制备薄膜的Te颗粒状态与复合薄膜的三阶非线性极化率的关系. 基于有效介质理论对复合薄膜的三阶非线性效应进行分析, 研究Te颗粒大小对Te/TeO2-SiO2复合薄膜的非线性光学性质的影响及其产生机理. 结果表明薄膜制备过电位增大, Te的粒径减小, 颗粒数量多, 颗粒分布趋于均匀, 使得金属颗粒的表面等离子体共振峰红移, 吸收强度增强, 导致三阶非线性光学效应增强, χ(3)由1064 nm的5.12×10-7 esu增大为532 nm的8.11×10-7 esu. 关键词: 碲 二氧化碲 复合薄膜 三阶非线性  相似文献   

4.
水溶性CdTe量子点的三阶光学非线性极化特性   总被引:1,自引:0,他引:1       下载免费PDF全文
利用超短脉冲Z扫描技术和光学Kerr效应研究了以巯基丙酸为稳定剂的CdTe量子点水溶液的三阶光学非线性极化特性. 在532nm,30ps和800nm,130fs脉冲激光激发下, 发现分别具有正负相反取值的三阶光学非线性折射率,自由载流子吸收和双光子吸收分别是这两种脉冲激光激发下三阶光学非线性吸收的起因. 测量得到CdTe量子点的三阶光学非线性极化率约为CS2的32倍, 在520—700nm光谱区的CdTe量子点的光学响应时间小于400fs. 关键词: CdTe量子点(QDs) Z扫描 三阶光学非线性极化特性 双光子吸收  相似文献   

5.
在纳秒时域,采用相位物体(PO)Z-扫描技术研究了一种新型金属簇合物溶液的瞬态热致非线性效应.该方法的最大优点是很容易区分瞬态热致非线性折射和三阶非线性折射.本文利用PO Z-扫描和传统Z-扫描研究了在8 ns脉宽、不同能量激光脉冲作用下[Tp*W(μ3-S)3Cu3Py3μ3-Br)](PF6)/DMF溶液的光学非线性.从声波方程和热传导方程出发,对实验结果进行了理论分析和数值模拟,理论值和实验结果很好的吻合.研究结果表明,样品溶液的非线性折射主要来源于瞬态热致非线性效应. 关键词: Z-扫描')" href="#">相位物体 Z-扫描 瞬态热致非线性折射 光克尔效应 DMF  相似文献   

6.
高潮  邱少君  杜渭松  侯超奇  郭红艳  杨钊飞 《物理学报》2011,60(4):44211-044211
侧链共轭的聚噻吩衍生物具有拓宽的共轭程度,有望成为一类性能优良的三阶非线性光学材料.合成了一种侧链共轭的噻吩共聚物:聚 -噻吩(POTVTh-Th),该聚合物与其均聚物相比,吸收光谱发生了明显的红移,禁带宽度为1.72eV.采用Z扫描技术在800nm下用飞秒激光器研究了该聚合物溶液和薄膜的三阶非线性光学特性,结果表明该共聚物四氢呋喃溶液中的三阶非线性极化率为8.84×10-10esu,聚合物薄膜的三阶非线性极化率为7.25×10-9esu,分别是其 关键词: 侧链共轭 噻吩共聚物 三阶非线性极化率 非线性吸收  相似文献   

7.
掺Ag纳米颗粒的BaTiO3复合薄膜的非线性光学特性   总被引:1,自引:1,他引:1       下载免费PDF全文
通过准分子激光(XeCl,308 nm,20 ns)在MgO(100)单晶衬底上制备了不同掺杂浓度的Ag:BaTiO3纳米复合薄膜,通过X射线衍射和X射线光电子能谱对薄膜的结构和组分进行了表征.在430 nm和470 nm附近观测到了不同浓度Ag纳米颗粒引起的等离子体吸收峰,通过z扫描技术对复合薄膜的三阶非线性光学特性进行了测量,并对其光学非线性的增强机制进行了讨论.  相似文献   

8.
主要从实验和理论两个方面,探讨了强受限尺寸区域内不同尺寸对CdSe量子点线性和非线性光学性质的影响.用吸收光谱研究了量子点尺寸与吸收峰之间的关系,用皮秒Z扫描技术研究了共振和非共振情况下(激发光波长分别为532和1064nm),尺寸与三阶非线性极化率之间的关系.基于电子能量状态理论和局域场增强理论对量子点进行分析,得到了CdSe不同尺寸的三阶非线性效应,研究了尺寸对量子点非线性光学性质的影响.结果表明,由激发态粒子数布局改变和纳米颗粒增大引起的非线性共振增强效应相当,二者共同作用使得三阶极化率增强20倍左右,且用532nm的共振频率激发4.3nm CdSe量子点时,χ(3)具有最大值2.0×10-11esu. 关键词: CdSe量子点 三阶非线性 Z扫描')" href="#">Z扫描 量子限域效应  相似文献   

9.
合成了一种侧链共轭的聚噻吩衍生物聚3-(5′辛基-噻吩乙烯基)噻吩(POTVTh),并通过溶液旋涂制备了聚合物薄膜.吸收光谱显示该聚合物薄膜具有较小的禁带宽度和宽的光谱响应.采用Z扫描技术在800 nm下用飞秒激光器研究了该聚合物薄膜的三阶非线性光学特性,非线性吸收系数为5.63×10-7cm/W,非线性折射率为-6.38×10-11 cm2/W,三阶非线性极化率为4.21×10-9esu,比侧链未共轭的 关键词: 聚噻吩衍生物 侧链共轭 三阶非线性极化率 非线性折射率  相似文献   

10.
通过原位吸附-受限生长聚合法成功制备了聚苯胺/碳纳米管(PANI/MWCNT)复合体.红外光谱和拉曼光谱证实了在碳纳米管(MWCNT)表面的包覆层为聚苯胺(PANI).紫外—可见吸收光谱表明随着MWCNT含量的增加PANI的吸收发生红移且强度提高.扫描电子显微镜和透射电子显微镜观察发现,PANI/MWCNT复合体直径为40—70nm,其中PANI的包覆层厚度约为15—20nm.利用四波混频方法测试它们的三阶非线性光学系数,结果发现PANI/MWCNT复合体的三阶非线性光学系数比纯PANI大,这说明在MWC 关键词: 碳纳米管 聚苯胺 复合体 三阶非线性光学系数  相似文献   

11.
夏春辉  陈志敏  吴谊群  宋瑛林 《物理学报》2005,54(11):5168-5172
应用Z扫描技术,在波长为532nm、脉宽为8ns条件下,对一种新型亚酞菁配合物三-α-(2,4-二甲基-3-戊氧基)溴硼亚酞菁的三阶非线性光学特性进行了研究,结果发现,该新化合物有较强的反饱和吸收(β=3.7×10-10 m/W)效应和非线性自聚焦折射效应(n2=7.2×10-11esu),其三阶非线性极化率χ(3)=1.1×10-11esu.分析了溴硼亚酞菁配合物特殊的锥形分子结构和重原子溴的轴向配位等因素对其三阶非线性光学性质的重要影响. 关键词: 亚酞菁 Z扫描 三阶光学非线性  相似文献   

12.
CaCu3Ti4O12 (CCTO) thin films were successfully prepared on LaAlO3 substrates by pulsed laser deposition technique. We measured the nonlinear optical susceptibility of the thin films using Z-scan method at a wavelength of 532 nm with pulse durations of 25 ps and 7 ns. The large values of the third-order nonlinear optical susceptibility, χ (3), of the CCTO film were obtained to be 2.79×10−8 esu and 3.30×10−6 esu in picosecond and nanosecond time regimes, respectively, which are among the best results of some representative nonlinear optical materials. The origin of optical nonlinearity of CCTO films was discussed. The results indicate that the CCTO films on LaAlO3 substrates are promising candidate materials for applications in nonlinear optical devices.  相似文献   

13.
Au-core CdS-shell composite nanoparticles were synthesized by a direct self-assembly process and integrated into BaTiO3 thin films. Characterization by transmission electron microscopy showed that the average diameter of these composite nanoparticles was about 8 nm. Using the femtosecond time-resolved optical Kerr effect method, we investigated the third-order nonlinear optical response of the Au@CdS nanoparticles embedded in the BaTiO3 thin films at a wavelength of 800 nm. An ultrafast nonlinear response and a large effective third-order nonlinear susceptibility of χ(3)=7.7×10-11 esu were observed. We attributed the enhancement of the third-order optical nonlinearity to a localized electric field effect originating from the core-shell structure under off-surface-plasmon resonance conditions. Received: 13 May 2002 / Revised version: 23 October 2002 / Published online: 3 April 2003 RID="*" ID="*"Corresponding author. Fax: +86-21/6510-4949, E-mail: sxqian@fudan.ac.cn  相似文献   

14.
The third-order optical nonlinearity of Ag-O-Cs thin films, where Ag nanoparticles are embedded into a CsxO semiconductor matrix, was measured by the femtosecond optical Kerr technique. The third-order nonlinear optical susceptibility, χ(3), of the thin films was estimated to be 1.1×10-9 esu at the incident wavelength of 820 nm. The response time, i.e. the full width at half-maximum of the Kerr signal, is as fast as 114 fs only. The intrinsic third-order optical nonlinearity can be attributed to the intraband transition of electrons from the occupied state near the Fermi level to the unoccupied state. It is suggested that such a nonlinearity is further enhanced by the local field effect that is present in the metallic nanoparticles composite thin films.  相似文献   

15.
从实验和理论两个方面,探讨了金属Ag不同掺杂浓度对Ag:Bi2O3复合膜线性和非线性光学性质的影响. 用吸收光谱研究了Ag浓度与Ag:Bi2O3复合膜表面等离子体共振带之间的关系;用皮秒Z-扫描技术研究了共振和非共振情况下(激发光波长分别为532nm和1064nm),金属Ag浓度与复合膜三阶非线性极化率的关系. 基于表面等离子体共振理论和局域场增强理论对复合膜进行了分析,得到了不同Ag浓度时Ag:Bi2O3复合膜的三阶非线性效应,研究了激发波长和金属浓度对复合膜线性和非线性光学性质的影响. 结果表明,等离子体共振增强和合适的金属掺杂浓度使得三阶极化率增强二个量级,在Ag浓度为35%左右和接近等离子体共振频率(相应吸收带位于560nm—622nm)的532nm激发时,χ(3)具有最大值2.4×10-9esu. 关键词: 金属纳米颗粒 复合膜 三阶非线性 表面等离子体共振  相似文献   

16.
The results of third-order nonlinear susceptibilities studies of Fe- and Zn-doped polyvinylpyrrolidone (PVP) aqueous solution in processes of third harmonic generation of Nd:YAG laser radiation are presented. Nonlinear susceptibilities of PVP:Fe and PVP:Zn were calculated to be 5×10-13 esu and 3×10-13 esu respectively. Third harmonic conversion efficiencies in these metallocomplexes were measured to be 8×10-7 and 5×10-7 respectively. The Z-scan method was applied to determine Kerr effect influence on frequency conversion process. The value of nonlinear refractive index of PVP:Fe at the wavelength of λ = 1064 nm was measured to be n 2 = - 6.7×10-13 esu. Received 30 November 2001 / Received in final form 27 March 2002 Published online 28 June 2002  相似文献   

17.
By controlling the oxygen pressure, single-phase CuO and Cu2O thin films have been obtained on quartz substrates using a pulsed laser deposition technique. The structure properties and linear optical absorption of the films were characterized by X-ray diffraction and UV–VIS spectroscopy. By performing z-scan measurements using a femtosecond laser (800 nm, 50 fs), the real and imaginary parts of the third-order nonlinear susceptibility, Re χ (3) and Im χ (3), of the films were determined. Both CuO and Cu2O films exhibited large optical nonlinearities, which is comparable to those in some representative semiconductor films such as ZnO and GaN films using femtosecond laser excitation. Compared with Cu2O films, the CuO films showed larger third-order nonlinear optical effects under off-resonance excitation. Furthermore, the mechanisms of the optical nonlinearities in CuO and Cu2O films are explained in the main text. It was suggested that the reasons of the difference in their nonlinear refractive effects may be related to the different electronic structure in CuO and Cu2O materials.  相似文献   

18.
主要从实验和理论两个方面,探讨了不同Au颗粒尺寸和不同基质对Au:TiO2和Au:Al2O3复合膜线性和非线性光学性质的影响.用吸收光谱研究了Au颗粒尺寸和基质与Au复合膜表面等离子体共振带之间的关系;用皮秒Z扫描技术研究了共振和非共振情况下(激发光波长分别为532nm和1064nm),Au颗粒尺寸和基质与复合膜三阶非线性极化率的关系.基于表面等离子体共振理论和局域场增强理论对复合膜进行了分析,得到了不同Au颗粒大小和不同基质时Au复合膜的 关键词: 金属纳米颗粒 复合膜 三阶非线性 表面等离子体共振  相似文献   

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