钕激光器锁模用的五甲川染料

本文给出了钕激光器锁模用的五甲川染料的物理、化学和锁模特性。找出了影响溶于1,2-二氯乙烷的五甲川染料溶液稳定性的因素。提出了一种提高染料稳定性的方法。和十一甲川染料相比,五甲川染料是一种廉价而好的锁模染料。     

XeCl准分子激光泵浦的无腔染料激光器和紫外-可见波段调谐染料激光器

（一）无腔染料激光器 一、引言 不使用共振腔便能得到强受激发射的光通称为放大自发辐射NIASE，一般也叫超辐射或超荧光。它是自发辐射在已形成粒子数反转分布的高增益激活介质中沿激活区轴向传播时通过感应发射过程依次行波放大所产生的。     

小信号双级染料激光放大器的优化设计

利用染料激光放大器的横向稳态抽运理论，研究了小信号双级染料放大器的抽运能量分配以及染料池长度的选取对激光增益的影响。对于其他参量确定的放大系统，存在着最佳的抽运能量分配比例和最佳的染料池长度的选取方法。通过自编程序的计算，可方便地找出特定系统染料池长度和抽运能量分配比例的最佳值。     

Amplified spontaneous emission in narrow-band pulsed dye laser oscillators--Theory and experiment

We have investigated the effect of amplified spontaneous emission (ASE) on the spectral and temporal characteristics of narrow-band pulsed dye laser oscillators. The space and time dependent rate equations for the molecular populations and photon fluxes have been solved numerically to study the dependence of ASE on various laser parameters and the effects of ASE on the spectral and temporal profile of the dye laser output. To account for the diffraction losses present in a real dye laser oscillator, appropriate feedback factors for the laser and ASE photon fluxes were introduced into the boundary conditions for the oscillator. These theoretical results have been substantiated by experimental measurements of ASE in a narrow-band pulsed dye laser oscillator. We show that a considerable reduction of ASE in a grazing incidence grating dye laser oscillator can be obtained by appropriately shaping the pump pulse. Oscillations observed in the temporal output of pulsed dye lasers are also discussed.     

Injection-locked dye laser pumped by a xenon-ion laser

Injection locking of a dye laser is reported for a 4-mirror ring-cavity dye laser pumped by a xenon-ion laser. Both a He-Ne laser and tunable CW dye laser were used as the injection sources.     

输出耦合对染料激光器的影响

采用简便的染料激光器速率方程组计算了输出耦合对器件阈值泵浦速率、输出功率和量子效率的影响.取得了有益的结果,对设计氙灯泵浦染料激光器和连续染料激光器有一定参考价值.     

Transmission of organic laser dyes under inclusion of stimulated emission

This paper describes a theoretical study together with a few experimental results of nonlinear dye transmission under inclusion of the influence of stimulated emission, due to a high-Qoptical resonator surrounding a transversely excited dye sample. The rate equation approach takes into account spatial attenuation of the exciting radiation. Formulas are derived for both the intensity dependent dye transmission and the resultant dye laser output intensity. The study comprises all relevant facts of dye laser operation, such as reabsorption, triplet effects, and excited state absorption (ESA).     

Electrochemical analysis of dye adsorption on aligned carbon nanofiber arrays coated with TiO2 nanoneedles for dye-sensitized solar cell

An electrochemical method has been developed to analyze dye absorption on the aligned carbon nanofiber arrays coated with TiO2 nanoneedles for dyesensitized solar cell. The unique nanostructure with the roughness factor of 90.6 provides a large effective surface area for dye adsorption. The experimental results showed that the dye molecules cover 39.7% of the TiO2 surface area which influences the performance of dye-sensitized solar cell. The electrochemical method provides the information of the coverage of dye molecules which is a key issue to optimize solar cell performance.     

Hybrid ZnO–Dye Hollow Spheres with New Optical Properties by a Self‐Assembly Process Based on Evans Blue Dye and Cetyltrimethylammonium Bromide

A facile one‐step process for the fabrication of hybrid ZnO–dye hollow spheres with novel optical properties has been discovered. Addition of Evans blue (EB) dye to cetyltrimethylammonium bromide (CTAB) results in the formation of CTAB‐EB micelles through an ionic self‐assembly process, and the resulting material acts as a soft template for the crystallization of ZnO upon addition of a zinc salt and ammonia under mild refluxing conditions. The formation mechanism of such hollow spheres has been investigated. These new hybrid ZnO–dye hollow spheres display distinct optical properties that differ from properties observed for the pure ZnO and dye components. This approach is a new and effective method for fabricating novel semiconductor–dye hybrids with unique electronic and optical properties and is expected to provide access to additional inorganic–organic materials with novel structures and unusual functionalities.     

A compartment model for fluorometric indication of tissue perfusion

Sodium fluorescein is an in vivo blood perfusion indicator for soft tissue. When fluorescein dye is introduced into the blood, it distributes throughout the vasculature and the extravascular space. Incident light from an external source causes the dye to fluoresce, the level of which is monitored by a photodetector placed over the tissue. In this study, theoretical analysis incorporating a multicompartmental model for dye distribution is applied to describe the relationship among perfusion, dye kinetics, and fluorescence readings. Errors in calculating perfusion from fluorescence are related to dye concentrations and to measurement errors. These error sources are minimized by selecting the measurement time. The alternatives of measurement during wash-in or during wash-out of dye are compared, as well as the alternatives of introducing dye by bolus injection or by constant infusion. Compensation of wash-in measurements for differences in skin pigmentation is accomplished by the matching of skin optical properties between incident and fluorescing wavelengths. A laboratory study at 80 measurement sites (from ten graded perfusion canine flaps) demonstrated a correlation of wash-in and wash-out perfusion data ranging from 0.88 to 0.96 at typical levels of fluorescein in blood. Since wash-in can be completed in a matter of a few minutes, this is likely to be preferable in the clinical setting to wash-out which can take much longer to complete.     

CuCl激光器泵浦的高效率窄线宽波导染料激光器

报道一台效率高、线宽窄的波导染料激光器;线宽4GHz,效率12.5％,ASE宽带背景为4.7％,发散角为3mrad。对几种染料谐振腔的输出特性进行了比较。     

Manipulation of light harvesting for efficient dye‐sensitized solar cell by doping an ultraviolet light‐capturing fluorophore

An organic fluorophore is doped into a mesoporous TiO₂ photoelectrode to absorb ultraviolet light and convert it to green light for more efficient light harvesting of N719 dye. This fluorescence conversion enables the absorption of additional green light by dye molecules by means of Förster resonance energy transfer between fluorescent compound donor and N719 dye acceptor. Owing to close fit between the emission peak of fluorophore and the absorption peak of N719 dye, the Förster resonance energy transfer effect enhances the incident photon to current conversion efficiency of the dye‐sensitized solar cells based on fluorophore‐doped TiO₂ photoelectrodes. Improved power conversion efficiency (8.03–8.13%) is also achieved for the fluorophore‐doped (10⁻⁴ M) dye‐sensitized solar cells compared with a cell without the doping of fluorophore (7.63%). Copyright © 2013 John Wiley & Sons, Ltd.     

Long pulse DCM dye laser

We describe a flashlamp pumped dye laser, incorporating both prepulse and simmer enhancement, which is capable of kW outputs for the 0.1 ms duration of the flashlamp pulse. The laser has been operated with the new dye DCM; we find that using oxygen or nitrogen gas in the dye solution greatly increases both laser amplitude and pulse duration.     

固体激光与铜蒸气激光混合抽运的染料激光放大实验

采用倍频Nd:YAG绿光激光器与铜蒸气激光器混合抽运双级染料激光放大器的实验方法,通过抽运激光器精确的脉冲同步控制和匹配技术,获得了9.0W的染料激光输出,第二级染料激光放大器对抽运激光的提取效率达到了26.6%,系统总提取效率达到了13.6%.实验研究了染料激光输出功率和抽运激光提取效率随染料激光波长的变化关系.     

Photoinduced Electron Transfer in Dye‐Sensitized SnO2 Nanowire Field‐Effect Transistors

Electron transfer from excited dye molecules (chlorophyll or fluorescein) to a semiconductor is demonstrated by photoaction and photoluminescence spectra on field‐effect transistors consisting of dye‐sensitized individual SnO₂ nanowires. The photoaction spectrum shows a much better resolution for nanowires non‐covalently functionalized with dye molecules than for dyes deposited on SnO₂ nanoparticle‐films. Possible reasons for the deviation between the photoaction spectra and ordinary optical absorption spectra as well as for the current‐tail appearing along the falling edge are addressed. In dye‐sensitized nanowires, electron transfer from photo‐excited dyes to nanowires is analyzed by comparing gate‐voltage dependences in photoaction and photoluminescence spectra. The importance of this study is in the understanding of electron injection and recombination provided, as well as the performance optimization of nanowire‐based dye‐sensitized solar cells.     

Ultrabright Fluorescent Silica Mesoporous Silica Nanoparticles: Control of Particle Size and Dye Loading

The synthesis of ultrabright fluorescent mesoporous silica nanoparticles (UFSNPs) of various sizes loaded with different amounts of fluorescent dye (Rhodamine 6G) is reported here. The dye is physically entrapped inside the nanochannels of the silica matrix created during templated sol–gel self assembly. Due to the specific nanoenvironment, the fluorescence of the encapsulated dye molecules remains unquenched up to very high concentrations, which results in relatively high fluorescence. The particle size (ranging from 20–50 nm) and dye loading (0.8–9.3 mg dye per g particles) are controlled by the timing of the synthesis and the concentration of several organotriethoxysilanes, which are coprecursors of silica. The quantum yields of the encapsulated dye range from 0.65 to 1.0. The relative brightness of a single particle is equivalent to the fluorescence of 30–770 free nondimerized R6G dye molecules in water, or to that of 1.5–39 CdSe/ZnS quantum dots. Despite the presence of some hydrophobic groups on the particles' surfaces, colloidal suspensions of the particles are relatively stable (as monitored for 120 days).     

输出功率50 W的脉冲染料激光放大器

推导了准稳态下横向抽运的脉冲染料激光放大器的简化速率方程,提出了双侧横向抽运方式的脉冲染料激光放大器的设计原则和设计方法.应用高功率脉冲染料激光放大器的物理设计结果,研制了输出功率为50 W的脉冲染料激光放大器的实验装置.采用铜蒸气激光(CVL)作为抽运光,在此染料激光放大器上进行了实验研究,获得染料激光输出功率为52 W,抽运激光功率提取效率为41%.给出了染料激光波长、注入染料激光功率以及抽运激光的时间和空间匹配特性与染料激光放大器输出激光功率和抽运激光功率提取效率的相互关系,讨论了染料溶液浓度对双侧横向抽运方式的脉冲染料激光放大器的输出光束质量的影响.     

Quantitative Television Fluoroangiography?The Optical Measurement of Dye Concentrations and Estimation of Retinal Blood Flow

The development of a system for the measurement of dye concentrations from single retinal vessels during retinal fluorescein angiography is presented and discussed. The system uses a fundus camera modified for TV viewing. Video gating techniques define the areas of the retina to be studied, and video peak detection yields dye concentrations from retinal vessels. The time course of dye concentration is presented and blood flow into the retina is estimated by a time of transit technique.     

蓝色染料激光器

研制了一台蓝色高功率单模染料激光器。当多谱线紫外Ar~+激光泵浦功率为4W时,在波长为432nm处单模输出达150mW。用这台激光器用磁场法反向照射Ca原子束,结果表明Ca原子被明显减速。