二茂铁基查尔酮衍生物的超快三阶非线性光学响应

合成三例二茂铁基查尔酮衍生物:1-二茂铁基-3-(5-溴噻吩-2-基)-2-丙烯-1-酮(1)、1-二茂铁基-3-(4-溴噻吩-2-基)-2-丙烯-1-酮(2)和1-二茂铁基-3-(5-氯噻吩-2-基)-2-丙烯-1-酮(3);采用1H NMR、13C NMR和HR-MS对化合物1～3进行了结构表征,并测定了其热学性质;运用密度泛函理论方法进行结构优化,并计算得到了它们的分子轨道能量和极化率;采用紫外-可见吸收光谱与Z-扫描技术(532nm,180fs)分别测定了三种化合物的线性和非线性光学性质。结果表明,化合物1～3的紫外吸收波长发生明显红移,且1的非线性吸收幅度、极化率和分子超极化率最大; 1、2和3均存在分子内电荷转移现象,表现出超快三阶非线性光学响应。     

三联噻吩基查尔酮衍生物的线性光学性质和超快非线性光学响应北大核心CSCD

以α-三联噻吩甲醛为原料,与3种二氯苯乙酮发生Claisen-Schmidt缩合反应,合成了3种含有三联噻吩基的查尔酮衍生物:1-(α-三联噻吩-2-基)-3-(2,4-二氯苯基)丙烯酮(a)、1-(2,5-二氯苯基)-3-(α-三联噻吩-2-基)丙烯酮(b)和1-(3,4-二氯苯基)-3-(α-三联噻吩-2-基)丙烯酮(c)。借助核磁共振波谱仪(^(1)H NMR、^(13)C NMR)和液-质联用谱仪(LC-MS)对其结构进行了表征;采用Z-扫描技术(600 nm,180 fs)测定了3个化合物的非线性光学吸收性能;运用含时密度泛函理论(TD-DFT)方法计算了它们的极化率(α_(0))、静态第一超极化率(β_(0))、振子强度(f_(0))、跃迁能(ΔE)、基态和最主要激发态之间的偶极矩差(Δμ)、最主要激发态的主要组成、最高占据分子轨道(HOMO)和最低空分子轨道(LUMO)之间的能隙,同时测定了它们的线性光学性质。结果表明,化合物c的紫外吸收波长、荧光发射波长、热稳定性、极化率均最大;化合物a—c均存在分子内电荷转移现象,非线性吸收均为双光子吸收,化合物a、b还有五阶非线性吸收,它们均表现出超快非线性光学响应,可作非线性光学研究备选材料。     

Bis(4,4′-dimethyl-2,2′-bipyridine)ruthenium(II) Complexes Containing 2-Arylimidazo-phenanthroline: Syntheses, Characterization and Third-order Nonlinear Optical Properties

ＩｎｔｒｏｄｕｃｔｉｏｎＯｒｇａｎｏｍｅｔａｌｌｉｃａｎｄｃｏｏｒｄｉｎａｔｉｏｎｃｏｍｐｌｅｘｅｓｈａｖｅｒｅ ｃｅｎｔｌｙｅｍｅｒｇｅｄａｓｐｏｔｅｎｔｉａｌｂｕｉｌｄｉｎｇｂｌｏｃｋｓｆｏｒｎｏｎｌｉｎｅａｒｏｐｔｉｃａｌ (ＮＬＯ )ｍａｔｅｒｉａｌｓ .1 6Ｃｏｍｐａｒｅｄｗｉｔｈｏｒｇａｎｉｃｍｏｌｅｃｕｌｅｓ ,ｍｅｔａｌｃｏｍｐｌｅｘｅｓｃａｎｈａｖｅａｌａｒｇｅｒｖａｒｉｅｔｙｏｆｓｔｒｕｃｔｕｒｅｓａｎｄａｍｕｃｈｇｒｅａｔｅｒｄｉｖｅｒｓｉｔｙｏｆｔｕｎａｂｌｅｅｌｅｃ ｔｒｏｎｉｃ…     

Nonlinear optical studies of 1-3-diaryl-propenones containing 4-methylthiophenyl moieties

The third-order nonlinear optical properties of chalcone derivatives have been studied using the single beam Z-scan technique. The dependence of χ⁽³⁾ on different donor and acceptor type substituents demonstrates the electronic nonlinearity of compounds. The largest value of nonlinear refractive index, n₂, measured for a high electron donor substituted molecule is −2.033 × 10⁻¹¹ esu. These molecules exhibit a strong two-photon absorption and interesting optical limiting of nanosecond laser pulses at 532 nm.     

Concentration dependent nonlinear refraction in chloroaluminum phthalocyanine/ethanol solution

Nonlinear refractive properties of chloroaluminum phthalocyanine (CAP) in ethanol solution are studied using the Z-scan technique with picosecond (ps) and nanosecond (ns) laser pulses at a wavelength of 532 nm. A transition from self-focusing to self-defocusing in CAP solution excited by 10 ns pulses is observed during the decrease of its concentration. This transition is due to co-existing excited-state refraction and transient thermal lensing effects. The experimental results are described very well using the rate-equation model and the theory of transient thermal refraction in liquids. The refractive cross sections of the excited-state are also obtained.     

Study on nonlinear optical absorption properties of [(CH3)4N]2[Cu(dmit)2] by Z-scan technique

The third-order optical nonlinearities of an organo-metallic compound, [(CH₃)₄N]₂[Cu(dmit)₂] (dmit²⁻=4,5-dithiolate-1,3-dithiole-2-thione), abbreviated as MeCu, dissolved in acetone are characterized by Z-scan technique with picosecond and nanosecond laser pulses in the near-infrared region. Two-photon absorption has been found when the sample solution is irradiated by 40 ps pulse width at 1064 nm and the two-photon absorption (TPA) coefficient β_TPA is 4×10⁻¹³ m/W. While excited by 15 ns laser pulses at 1053 nm, the Z-scan spectra reveal strong reverse saturable absorption (RSA) and the nonlinear absorption coefficient β_RSA is estimated to be as high as 7.07×10⁻¹¹ m/W which is much larger than β_TPA. An explanation for this enhancement is given. All the results suggest that MeCu may be a promising candidate for the application to optical limiting in the near-infrared region.     

CdSe/ZnS核-壳结构量子点的非线性光学吸收

利用开孔Z扫描技术研究了吸收峰分别为553 nm和503 nm的两种尺寸CdSe/ZnS核-壳结构量子点溶液的非线性吸收性质.对于532 nm,6 ns激光脉冲,两种材料均表现出饱和吸收向反饱和吸收转化的现象.数值模拟结果表明：当吸收峰波长大于激光波长时,饱和吸收过程由快、慢两种机制组成,分别对应基态载流子被激发至不同的激发态,而强光下的反饱和吸收与快过程相关;当吸收峰波长小于激光波长时,饱和吸收主要由快过程机制引起,强光下的反饱和吸收源自激发态吸收和双光子吸收.我们的研究结果表明半导体量子点是研制光开关和光限制器件的理想候选材料.