CdTe量子点-罗丹明B荧光共振能量转移猝灭法测定金银花中的微量铜

研究CdTe量子点(供体)和罗丹明B(受体)之间荧光共振能量转移的最佳条件,建立了荧光共振能量转移猝灭法测定金银花中微量铜的新方法.采用十六烷基三甲基溴化铵,在pH 6.00的Tris-HCl缓冲液中,Cu2+能对能量转移体系中罗丹明B荧光峰强猝灭从而测定铜的含量.Cu2+浓度在1.3×10-4～3.1×10-2 μg...     

CdTe量子点与罗丹明B水溶液体系下的双光子激发荧光共振能量转移

采用时间分辨荧光光谱技术研究了在双光子激发下不同尺寸的量子点与罗丹明B 之间的荧光共振能量转移. 研究结果表明, 在800 nm的双光子激发条件下, 体系间能量转移效率随着供体吸收光谱与受体荧光光谱的光谱重叠程度增加而增加; 理论分析表明, 供体和受体间的Förster半径增加是导致其双光子能量转移效率增大的物理原因. 同时, 研究了罗丹明B浓度对荧光共振能量转移效率的影响. 研究结果表明, 量子点的荧光寿命随着罗丹明B浓度的增加而减小; 量子点与罗丹明B之间的荧光共振能量转移效率随着罗丹明B浓度的增加而增加; 当罗丹明B浓度为3.0×10^-5 mol·L^-1时, 双光子荧光共振能量转移效率为40.1%.     

Enhanced Emission Induced by FRET from a Long-Lifetime, Low Quantum Yield Donor to a Long-Wavelength, High Quantum Yield Acceptor

We report observation of high quantum yield, long-lifetime fluorescence from a red dye BO-PRO-3 excited by resonance energy transfer (RET). The acceptor fluorescence was highly enhanced upon binding to the donor-labeled DNA. A ruthenium complex (Ru) was chosen as a donor in this system because of its long fluorescence lifetime. Both donor and acceptor were non-covalently bound to DNA. Emission from the donor-acceptor system (DA) at wavelengths exceeding 600 nm still preserves the long-lifetime component of the Ru donor, retaining average fluorescence lifetimes in the range of 30–50 ns. Despite the low quantum yield of the Ru donor in the absence of acceptor, its overall quantum yield of the DA pair was increased by energy transfer to the higher quantum yield acceptor BO-PRO-3. The wavelength-integrated intensity of donor and acceptor bound to DNA was many-fold greater than the intensity of the donor and acceptor separately bound to DNA. The origin of this effect is due to an efficient energy transfer from the donor, competing with non-radiative depopulation of the donor excited state. The distinctive features of DA complexes can be used in the development of a new class of engineered luminophores that display both long lifetime and long-wavelength emission. Similar DA complexes can be applied as proximity indicators, exhibiting strong fluorescence of adjacently located donors and acceptors over the relatively weak fluorescence of separated donors and acceptors.     

罗丹明B的共振散射光谱研究

研究了罗丹明B(RhB)的共振光散射的特性与机理。在 pH =- 0 38至 pH 4 10的酸性溶液中 ,共振光散射信号随pH值增大而增强 ,近中性时散射强度达到最大。散射强度随波长的变化不符合瑞利散射定律。RhB的荧光激发光谱与发射光谱有部分重叠 ,共振散射峰处于荧光激发峰和荧光发射峰之间。在三维荧光等高线光谱图中 ,瑞利散射线与荧光等高线相交。在光偏振实验中 ,测得共振散射光的偏振度P≈ 0 1。上述实验结果揭示RhB的共振散射光主要是共振荧光。共振光散射信号随 pH值增大而增强的机理是RhB酸碱平衡移动导致荧光型体的形成。RhB的共振散射峰位于吸收曲线轮廓之中 ,共振光散射受光吸收的影响 ,因此 ,散射光强度与浓度之间不是严格的线性关系。     

Energy transfer probe for the characterization of luminescent photonic crystals morphology

We evaluated energy transfer probe for the characterization of luminescent photonic crystals morphology. It demonstrates a monomolecular filming of fluorescent chelated complexes inside photonic crystal voids. Either direct fluorescence quenching of excited fluorescent donors by the acceptors in case of low concentration of fluorescent centers or fluorescence quenching accelerated by energy migration over fluorescent donor ions in case of 100% of sites occupied by donors is demonstrated in 2D space contrarily to the powder samples of the same complexes where energy transfer occurs in 3D space.     

Spontaneous emission in micro- and nano-structures

Spontaneous emission of emitters governing the performance of optoelectronic devices is a fundamental phenomenon, and it has strong environment-dependent characteristics. In this article, we mainly review the experimental and theoretical progresses in the control of spontaneous emission by manipulating optical modes with photonic crystals, optical microcavities and metallic nanostructures. The spontaneous emission from emitters in photonic crystals can be modified by the local density of states, and by employing photonic crystals, the devices’ efficiency is enhanced, the angular radiation pattern can be engineered, and highly efficient optoelectronic devices are achieved through decreasing the radiative lifetime. In quantum optical devices, microcavities would alter the lifetime of an excited state through tuning the resonance in the frequency and positioning between the emitters and cavity field, and inducing the emitters to emit spontaneous photons in a desired direction. The emerging enhanced electromagnetic field near metallic nanostructures can help to control and manipulate the spontaneous emission of an emitter. The use of micro- and nano-structures to manipulate spontaneous emission will open unprecedented opportunities for realizing functional photonic devices.     

Spontaneous emission in micro- and nano-structures

Spontaneous emission of emitters governing the performance of optoelectronic devices is a fundamental phenomenon, and it has strong environment-dependent characteristics. In this article, we mainly review the experimental and theoretical progresses in the control of spontaneous emission by manipulating optical modes with photonic crystals, optical microcavities and metallic nanostructures. The spontaneous emission from emitters in photonic crystals can be modified by the local density of states, and by employing photonic crystals, the devices’ efficiency is enhanced, the angular radiation pattern can be engineered, and highly efficient optoelectronic devices are achieved through decreasing the radiative lifetime. In quantum optical devices, microcavities would alter the lifetime of an excited state through tuning the resonance in the frequency and positioning between the emitters and cavity field, and inducing the emitters to emit spontaneous photons in a desired direction. The emerging enhanced electromagnetic field near metallic nanostructures can help to control and manipulate the spontaneous emission of an emitter. The use of micro- and nano-structures to manipulate spontaneous emission will open unprecedented opportunities for realizing functional photonic devices.     

Stimulated resonance Raman scattering of Rhodamine B

Stimulated resonance Raman scattering (SRRS) of the Rhodamine B (RhB) in the methanol (CH₃OH) or ethanol (C₂H₅OH) solutions have been observed. SRRS from RhB can be distinguished from the amplified spontaneous emission (ASE) of RhB with increasing the input laser energy. When the RhB is dissolved in the methanol or ethanol (10^?3 mol/L), the RhB have the different peak wavelengths of SRRS, ASE, fluorescence and absorption, respectively. SRRS can be amplified by the ASE gain when the SRRS is near the peak of the ASE, and the peak wavelength of SRRS coincides with the maximal intensity wavelength of ASE.     

半导体量子阱材料微加工光子晶体的光学特性

利用聚焦离子束刻蚀方法和电子束制版结合干法刻蚀方法制备了二维近红外波段光子晶体，发现两种方法都可以制备出均匀的二维光子晶体，聚焦离子束方法操作简单，电子束制版结合干法刻蚀方法操作步骤复杂.光谱测试表明，利用聚焦离子束方法在有源材料上刻蚀的光子晶体不发光，而电子束制版结合干法刻蚀方法制备的小晶格常数光子晶体即使有些无序，其出光效率也提高到没有光子晶体时的两倍.对两种方法所加工的光子晶体不发光和提高出光效率的机理进行了分析. 关键词： 聚焦离子束 电子束制版 光子晶体 出光效率     

pH-Dependent fluorescence and singlet energy transfer in water-soluble polymers containing eosin and phenol red chromophores

The pH-dependent fluorescence and energy transfer properties of water-soluble polyacrylamide labeled with a donor (eosin) and acceptor (phenol red) were studied. Eosin emission intensity decreases with pH increases. This observation corresponds to the expectation that the fluorescence intensity of eosin should diminish with pH increases resulting from increased spectral overlap between dyes. The lower energy transfer efficiency compared to a pH sensor made with the same polymer, but with a cross-linker, can be explained by the larger distances between the two chromophores resulting from conformational flexibility and electrostatic repulsion of the chromophore ions.     

Controlling the photoluminescence spectroscopy of quinacrine dihydrochloride by SiO_2 inverse opal photonic crystal

Manipulation of the photoluminescence spectra of light-emitting materials doped in three-dimensional （3D） inverse opal photonic crystals is investigated. Quinacrine dihydrochloride molecules doped highly ordered SiO2 inverse opal is successfully synthesized by co-assembly combined with double-substrate vertical infiltrate method. The quinacrine dihydrochloride-doped and-undoped SiO2 inverse opals each exhibit an apparent photonic band gap （PBG） in the visible light region. Significant suppression of the emission is observed when the PBG is overlapped with the quinacrine dihydrochloride emission bands. The mechanism of suppression effect of PBG in inverse opal on the fluorescence intensity of quinacrine dihydrochloride molecules is studied.     

Electronic-Excitation Energy Transfer between Dye Molecules Adsorbed in One-Dimensional Photonic Crystals

Electronic-excitation energy transfer between molecules of Coumarin 7 (donor) and Rhodamine B (acceptor) have been experimentally investigated in one-dimensional photonic crystals based on oxidized mesoporous silicon and in a similar matrix, which does not possess the properties of a photonic crystal. The efficiencies of excitation transfer between donor and acceptor molecules have been determined based on the donor-fluorescence quenching and sensitized acceptor luminescence. It is established that the efficiency of electronic-excitation energy transfer in a photonic crystal increases in comparison with that for porous silicon.     

Optical third-harmonic generation in one-dimensional photonic crystals and microcavities

The formalism of nonlinear transfer matrices is used to develop a phenomenological model of a cubic nonlinear-optical response of one-dimensional photonic crystals and microcavities. It is shown that third-harmonic generation can be resonantly enhanced by frequency-angular tuning of the fundamental wave to the photonic band-gap edges and the microcavity mode. The positions and amplitudes of third-harmonic resonances at the edges of a photonic band gap strongly depend on the value and sign of the dispersion of refractive indexes of the layers that constitute the photonic crystal. Model calculations elucidate the role played by phase matching and spatial localization of the fundamental and third-harmonic fields inside a photonic crystal as the main mechanisms of enhancement of third-harmonic generation. The experimental spectrum of third-harmonic intensity of a porous silicon microcavity agrees with the calculated results.     

Front Cover Picture: Laser & Photon. Rev. 7(4)/2013

This is the schematic illustration of photonic crystal enhanced chemiluminescence intensity of the oxalate ester peroxide chemiluminescence system. The emission light is inhibited inside the photonic crystal and significantly enhanced at the surface owing to its Bragg scattering. When the stopband of the photonic crystal is matched with themaximum emission wavelength, the chemiluminescence intensity could be enhanced 44.9 times. (Picture: X. Shi et al. 10.1002/lpor.201300031 , pp. L39–L43, in this issue)     

CdTe量子点-罗丹明B荧光共振能量转移法测定溶菌酶

合成了以硫代乙醇酸为稳定剂的CdTe量子点,以发射波长为530 nm的量子点为供体,罗丹明B为受体,建立一种以十六烷基三甲基溴化铵为介质的荧光共振能量体系检测溶菌酶含片中溶菌酶含量的方法。结果表明:在pH=5.0时,溶菌酶的浓度与共振能量转移效率降低值在2×10^-7~ 8×10^-6 mol·L^-1范围内呈线性关系,其线性方程为Y=306.07-13.85X,相关系数为0.991 0,检出限为2×10^-8 mol·L^-1,RSD为5.8%,平均回收率为101%(n=5)。     

Thermal radiation from photonic crystals: a direct calculation

A classical simulation of equilibrium thermal emissivity from dispersive, lossy photonic crystals is presented. Normal emission results consistent with those assuming Kirchoff's law are obtained; i.e., a photonic crystal does not emit more than what a blackbody does. Significant enhancement, however, can be achieved over the radiation intensity from a uniform slab, indicating the potential usefulness of photonic crystals in incandescent lighting and thermal photovoltaic applications.     

微米光子回路中能量的荧光显示与调节

基于弯曲的罗丹明B(rhodamine B)掺杂聚合物微米线,搭建了Y型分束器、微米线-环形腔耦合结构等典型微米光子回路;采用锥形光纤耦合的方式,将光能量导入回路并在微米线中激发荧光;通过移动锥形光纤增加光的传输距离,分析能量的输出强度与传输长度之间的关系。研究发现,通过激发出的荧光光路强度,可显示回路中的能量沿微米线轴线周期性地衰减振荡,并在微米线弯折处发生相位跃变;回路输出端能量随传输距离的增加呈周期性变化,且在半个周期内,可将Y型分束器分光比从1.3调节到2.4(<2μm),使耦合结构中单个输出端的强度峰谷比达到2.1(<6μm)。利用锥形光纤耦合激发出的荧光,可在远场直接显示回路的能量传输状态,并在传输距离改变时对能量的耦合情况进行实时反映,实现回路输出性能的大范围调节,为复杂微光子器件的搭建及性能调节提供了一种直观、简便的方法。     

The stimulated Raman scattering competition between solute and solvent in Rhodamine B solution

The competition between the stimulated resonance Raman scattering(SRRS) of Rhodamine B(RhB) and the stimulated Raman scattering(SRS) of ethanol(C2H5OH) is observed at the RhB in C2H5OH solution.For different concentrations of the solution,the peak wavelengths of the SRRS,the amplified spontaneous emission(ASE),the fluorescence and the absorption of RhB are different.The SRRS of RhB and the SRS of C2H5OH are simultaneously generated when the concentration of the solution is 10 5 mol/L and the energy of the excitation laser is 20.4 mJ.Otherwise,only either the SRRS of RhB or the SRS of C2H5OH is generated.The SRRS can be amplified by the ASE gain when the SRRS is near the peak of the ASE,and the peak wavelength of the SRRS coincides with the wavelength of the maximal intensity ASE.     

Rhodamine B absorbed by anodic porous alumina: Stokes and anti-Stokes luminescence study

An organic dye, rhodamine B (RhB) solution, has been used to impregnate anodic porous alumina (PA) in order to form RhB/PA nanocomposites. The photoluminescence (PL) spectra of PA films impregnated with RhB are investigated and compared with those in liquid solution. The PL mechanism of RhB/PA nanocomposites has been investigated through the effect of energy excitation. We show the possibility of energy transfer from alumina nanocrystallites to RhB molecules. The interactions between chemical species in the internal surface of PA and the RhB molecules can play a key role in PL emission, which has been proved by the Fourier transform infrared (FTIR) measurements. Moreover, it is also found that the PL intensity of the nanocomposite increases with the PL of the PA layer. The effective cross section of RhB in PA has been estimated to be in the order of . An anti-Stokes PL (APL) has been observed from RhB/PA. The linear variation of the APL intensity with the laser power (I_APLαP^0.97) indicates that one photon is involved in emission process.     

Enhancing fluorescence of tricolor fluorescent powders by silica inverse opals

Silica inverse opal photonic crystals (PCs) were fabricated by using a sacrificial polymer template method, and were characterized by scanning electron microscopy and reflection spectra. The fluorescence of tricolor fluorescent powders has been enhanced obviously by silica inverse opals as the emission wavelengths of the tricolor fluorescent powders are in the range of stop bands of the inverse opal PCs, which demonstrates that the PCs will be efficient and selective reflection mirrors. A promising application of the strategy would be in novel effective lighting devices. PACS 42.70.Qs; 78.55.-m; 78.55.Mb; 78.68.+m; 78.67.-n An erratum to this article can be found at