共查询到20条相似文献,搜索用时 15 毫秒
1.
Non-linear optothermal properties of metal-free phthalocyanine 总被引:1,自引:0,他引:1
Hossin A. Abdeldayem Donald O. Frazier Benjamin G. Penn David D. Smith Curtis E. Banks 《Thin solid films》1999,350(1-2):245-248
The non-linear optical properties of metal-free phthalocyanine (MFPC) thin films were examined using the second harmonic at 532 nm from a pulsed Nd:YAG laser, and the continuous wave He–Ne and Ar+ lasers. The He–Ne laser transmission at fixed input intensity was found to increase temporally within a period of 12 h. The third-order non-linear susceptibilities (χ(3)) by four-wave mixing were measured for films of different thickness. The saturation intensity of MFPC, and its absorption cross-section, at 633 nm from a He–Ne laser, are reported. An optical bistability was recorded using a He–Ne laser. An AND logic gate was also demonstrated in the system. These phenomena in the system are attributed to refractive index modulation by thermal excitations. 相似文献
2.
Kishore SridharanV. Tamilselvan D. YuvarajK. Narasimha Rao Reji Philip 《Optical Materials》2012,34(4):639-645
Lead Telluride (PbTe) nanorods have been uniformly grown on silicon substrates, using the thermal evaporation technique under high vacuum conditions. The structural and morphological studies are done using X-ray diffraction and scanning electron microscopy. Optical nonlinearity studies using the open aperture z-scan employing 5 ns and 100 fs laser pulses reveal a three-photon type absorption. For nanosecond excitation the nonlinear absorption coefficients (γ) are in the order of 10−22 m3 W−2 and for femtosecond excitation it is in the order of 10−29 m3 W−2. The role of free carriers and excitons in causing the nonlinearity in both excitation time domains is discussed. Results indicate that PbTe nanorods are good optical limiters with potential device applications. 相似文献
3.
We report here for the first time, on the comparative studies of the photophysical and optical limiting behavior of our two novel phthalocyanines namely 2(3), 9(10), 16(17), 23(24)-tetrakis-(4-(5-methylhex-1-yn-3-yloxy)) phthalocyanines 2, and 2(3), 9(10), 16(17), 23(24)-tetrakis-(4-(5-methylhex-1-yn-3-yloxy)) phthalocyaninato zinc (II) (3) in solution and thin films. Nonlinear optical (NLO) properties of the samples in solution and contained in polysulfone (PSU) thin films were evaluated using Z-scan technique at 532 nm and 10 ns pulsed duration. Effects of aggregation and disaggregation on the NLO performance of metal-free phthalocyanine are reported in detail. Our findings showed that the prepared Pcs show larger nonlinear absorption coefficient and lower limiting thresholds when embedded in polysulfone films compared to in solutions. The values of nonlinear susceptibility and hyperpolarizability recorded for 3-PSU in this work are respectively, ∼2.09 × 10−8 esu and ∼1.02 × 10−26 esu. These values are among the largest values reported for phthalocyanines and other macrocycles doped on polymer matrices. 相似文献
4.
We report an investigation of third-order optical nonlinearities in several nonlinear optical crystals using the Z-scan technique with femtosecond laser pulses at 780 nm wavelength. The crystals studied include LiNbO3:MgO, KTiOAsO4, KTiOPO4, β-BaB2O4 and LiB3O5, which are extensively used for ultrashort-pulse second-harmonic generation and optical parametric oscillation. The nonlinear refractive index n2 in these crystals has been determined to be in the range from 10−16 to 10−15 cm2/W. No two-photon absorption has been observed. The experimental results are compared with the two-band model for the bound electronic Kerr nonlinearity. It is shown that the measured n2 values in β-BaB2O4 and LiB3O5 are one order of magnitude smaller than those of LiNbO3:MgO, KTiOAsO4, KTiOPO4, which is in agreement with the theoretical prediction. 相似文献
5.
Ag and Cu nanowires were separately fabricated in a direct current electric field using a solid-state ionic method, and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Their optical nonlinearities induced by 8 ns laser pulses from a frequency-doubled, Nd:YAG laser at 532 nm, were investigated using the Z-scan technique. Experimental results indicate the metal nanowires have obvious positive refractive nonlinearities and reverse saturated absorption behaviors. The self-focusing behaviors of Ag and Cu nanowires can be attributed to Kerr-induced self-focusing of laser radiation, the nonlinear refractive indexes of Ag and Cu nanowires are n2 = 1.7 × 10− 11 esu and n2 = 2.4 × 10− 11 esu respectively, and the two-photon process of Ag and the one-photon process of Cu are responsible for the difference between Ag and Cu nanowires suspended in de-ionized water in nanosecond nonlinear absorptions. 相似文献
6.
Metal nanocluster composite glass prepared by 200 keV Ag ions' implantation into silica with dose of 2 × 1017 ions/cm2 has been studied. The formation of sandwiched nanocluster-nanovoid-nanocluster structures has been evidenced by in situ transmission electron microscopy experiment (TEM). Fast nonlinear optical refraction and nonlinear optical absorption coefficients were measured at 532 nm and 1064 nm of wavelength by the Z-scan technique. The third-order nonlinear susceptibility χ(3) of this kind of sample was determined to be 4.0 × 10−8 esu at 532 nm and 9.0 × 10−8 esu at 1064 nm, respectively. 相似文献
7.
π电子共轭键结构对材料非线性光学性能影响研究 总被引:1,自引:1,他引:0
合成了具有不同π电子共轭键3个新的有机光学材料4-(吡啶-4-乙烯),4'-(N,N-二羟乙基氨基)二乙烯苯(a),N-((4-(N,N-二羟乙基氨基)-苯亚甲基)-4-(吡啶-4-乙烯)苯胺(b)和4-(吡啶-4-乙烯),4'-(N,N-二羟乙基氨基)偶氮苯(c),使用脉宽8ns波长532nm调Q倍频ns/ps Nd:YAG脉冲激光系统测试了它们的非线性光学性能,研究了分子结构与非线性光学性能之间的关系.结果显示这些化合物具有大的三阶非线性光学系数,这可能来源于它们长的D-π-A共轭电子结构;以N=N双键为共轭键的化合物的非线性光学性能优于以C=N或G=C双键为共轭键的化合物. 相似文献
8.
An organic and inorganic hybrid material was prepared from a nonlinear optically active imidazole derivative 4-(nitrophenyl)-2,4-Bis-(4,4′-[N,N-bis-(2-hydroxyethyl)aminophenyl]) imidazole and metal alkoxide of Nb(V) via sol-gel process. The second-order nonlinear optical and pyroelectric properties of the hybrid film were investigated in terms of the second harmonic generation (SHG) and pyroelectric coefficient measurement. The SHG coefficient d33 was found to be 29.3 pm/V at the fundamental wavelength of 1064 nm and the pyroelectric coefficient P was found to be 1.47 × 10− 6 C/cm2 K. 相似文献
9.
Composition dependent structural, optical nonlinear and limiting properties of PVA capped Zn1-x-yCdxCuyS quantum dots at different Cu:Zn ratio synthesized by insitu technique is subjected to detailed investigation. Cubic phase of the quantum dots were identified from XRD with particle size in the range 2.5 nm–3.5 nm find excellent correlation with the particle size measured from TEM. With increase in Cu concentration: systematic increment in lattice parameter, red shift in absorption edges and luminescence quenching is observed. Raman scattering reveals good photoactivity evidenced by intensity variation and shifting of LO and TO phonon modes. The intensity dependent third order nonlinearity is studied using Q switched Nd: YAG laser with 532 nm irradiation. Progressive increase in 3 PA coefficient indicated that prepared samples exhibit good nonlinear and optical limiting properties. 相似文献
10.
A new nonlinear optical (NLO) chromophore 4-dicyanomethylene-2-methyl-6- {4-[4-(N-ethyl-N-hydroxyethylamino)phenylazo]}styryl-4H-pyran (AZP), which features extended conjugated chain based on DCM laser dye, was synthesized and functionalized with alkoxysilane for materials processing. Hybrid films containing chromophore AZP and DCM were prepared via a sol-gel processing. The d33 values of films containing AZP are 39-48 pm/V varying with concentration of chromophores, which is similar to that containing DCM. By tuning the organic content, the thermal stability of d33 values can be significantly improved by about 30 °C, about 15 °C higher than those containing DCM. The residual rotational stress, along with cavity between chromophores and matrix, is proposed to contribute to the stability of NLO activity of hybrid films. 相似文献
11.
12.
The nonlinear optical properties of 2,9,16,23-phenoxy-phthalocyanine (Pc1) and 2,9,16,23-phenoxy-phthalocyanine-zinc (Pc2) in solution were investigated under excitation with nanosecond laser pulses at 532 nm. Based on five-level model, the nonlinear absorption in nanosecond regime was theoretically analyzed. The A-OS and OL behavior of Pc1 and Pc2 were further investigated with the pump–probe technique and transmission measurement technique. The results show that the A-OS response time is determined by the lifetime of the first triplet excited state of molecule, and Pc1 and Pc2 exhibit strong optical limiting effect at nanosecond laser pulses. These studies make the samples a promising possibility for device realization. 相似文献
13.
Konstantinos Iliopoulos George Chatzikyriakos Maria DemetriouTheodora Krasia-Christoforou Stelios Couris 《Optical Materials》2011,33(8):1342-1349
The synthesis and characterization of novel micellar nanohybrids with controllable sizes consisting of palladium nanosized core and covered by well-defined poly(lauryl methacrylate)-block-poly(2-(acetoacetoxy)ethyl methacrylate) (pLauMA-b-pAEMA) diblock copolymers are reported. Their nonlinear optical (NLO) response (i.e. nonlinear refraction and absorption and the third-order susceptibility χ(3)) is also studied under 35 ps laser excitation both in the visible and in the infrared and found to be insensitive to the size of the micelles while it was found to be greatly affected by the molar fraction of the AEMA block. To the best of our knowledge it is the first time that such Pd micellar nanohybrids are synthesized and investigated towards their NLO properties. The magnitude of the nonlinear optical response of these nanohybrids renders them promising candidates for potential optoelectronic applications. 相似文献
14.
Jiasong Zhong Weidong Xiang Zhaoping Chen Haijun Zhao Xiaojuan Liang 《Materials Science and Engineering: B》2013,178(15):998-1003
Cu nanocrystals embedded in sodium borosilicate glass of varied Cu contents from 0.5 to 1.5 wt% have been successfully prepared through a sol–gel process. According to the results of X-ray diffraction (XRD) and the energy dispersive X-ray spectrometry (EDS), the metal Cu nanocrystals in cubic crystal system were well distributed inside glass matrix. Fourier Transform Infrared (FTIR) indicated the sodium borosilicate matrix had no major structural change for gels with different Cu contents. The optical absorption peaks due to the surface plasmon resonance of Cu particles were observed in the wavelength range of 550–600 nm. The absorption peak showed a red-shift trend with increasing Cu contents from 0.5 to 1.5 wt%. Transmission electron microscopy (TEM) revealed the existence of spherical Cu nanocrystals in the matrix. The diameter of Cu nanocrystals varied from 1 to 3.5 nm. Furthermore, the third-order nonlinear optical properties were investigated by Z-scan technique at 800 nm. Experimental results indicated the Cu nanocrystals have obvious positive refractive nonlinearities and reverse saturated absorption performance. 相似文献
15.
Franco DAmore Marta Lanata Silvia M. Pietralunga Maria C. Gallazzi Giuseppe Zerbi 《Optical Materials》2004,24(4):661-665
In this paper we present the study of the linear and nonlinear optical properties of organic films based on mixing a polymeric matrix (PMMA) and a highly nonlinear organic material recently synthesised and characterised, namely (5,5′-Bis(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadien-1-ylidene)-5,5′-dihydro-2,2′-bithiophene), with the prospective of reaching a good compromise between good processability and high nonlinear optical (NLO) properties of the solid solution. Linear optical characterisation is performed by means of variable angle spectroscopic ellipsometry in the spectral range between 260 and 1700 nm. Third order NLO properties of the samples have been investigated by third harmonic generation at fundamental wavelength of 1500 nm. Different guest/host concentrations have been studied. Due to the high solubility of the guest into the polymeric matrix, we have been able to reach concentration up to 50% in weight, reaching an enhancement of the NLO properties of PMMA by three order of magnitudes. 相似文献
16.
Yunhe Zhang 《Materials Letters》2008,62(19):3453-3455
Poly(aryl ether ketone) containing cobalt phthalocyanine (PAEK-CoPc) is synthesized. The resulting polymer has good solubility and thermal stability. It shows optical absorption in the visible region, and exhibits blue photoluminescence. SEM images reveal that cotton morphology is shown when a solution of PAEK-CoPc in CHCl3 is mixed with 4 equiv of Bipy, and then dried on a substrate. The third order nonlinear optical property of PAEK-CoPc solution is characterized by Z-scan measurement at 532nm with 4.5ns pulses and the third order nonlinear optical susceptibility χ(3) is 1.11 × 10− 11esu in the non-resonant region. 相似文献
17.
18.
Tingchao He 《Journal of Modern Optics》2013,60(18):3013-3020
The nonlinear optical properties of p-aminoazobenzene (PAAB), methyl orange (MO) and p-dimethylamino benzene arsenic acid (PDBAA) were investigated by a single beam Z-scan technique, respectively. Their solution samples all exhibited large nonlinear refractive indices under the excitation of a 633 nm laser. Among the three azo dyes, PDBAA showed the largest value of nonlinear refractive index. Moreover, the process of nonlinear refraction induced by the laser thermal effect was also analyzed in this paper. 相似文献
19.
In-doped ZnO (IZO) nanowires were grown using the chemical vapour deposition method. The IZO nanowires have been characterized by scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) and UV–Visible spectroscopy. The PL results demonstrated a larger band-gap for the IZO nanowires in comparison to the undoped ZnO. Two major emission peaks were observed for the IZO nanowires, one originated from the free exciton recombination (ultraviolet emission) and another possibly related to the deep-level emission (visible emission). Furthermore, the nonlinear optical characteristic of the nanowires was studied using picosecond Z-scan technique. The experimental results show that the two and three-photon absorption coefficient of samples were able to be observed. These studies make the promising potential applications of the samples in the development of multifunctional all-optical devices. 相似文献
20.
This work reports on nonlinear optical properties of some azo-functionalized azulene derivatives. Linear and nonlinear optical absorption, second- and third harmonic generation were used as diagnostic tools. It was demonstrated that light induced a surface pattern on thin films containing the studied compounds. The results indicate an important role of thiazole substitution for enhancing NLO properties of the azulene derivatives. 相似文献