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Method Article
介绍了飞秒近红外刺激拉曼光谱仪的信号生成和优化、测量、数据采集和数据处理的详细信息。近红外刺激拉曼研究β-胡萝卜素在苯的兴奋状态动力学作为代表性的应用。
Femtos2 时间解刺激拉曼光谱是一种有希望的方法,用于观察近红外(近 IR) 过渡的短寿命瞬变的结构动力学,因为它可以克服近红外区域自发拉曼光谱仪的低灵敏度。在这里,我们描述了我们最近开发的一个飞秒时间解析近红外多路复用刺激拉曼光谱仪的技术细节。还提供了信号生成和优化、测量、数据采集以及记录数据的校准和校正的描述。我们介绍了光谱仪的应用,以分析环胡萝卜素在苯溶液中的兴奋状态动力学。在第二低兴奋单一 (S2)状态和最低兴奋单一 (S1)状态中清楚地观察到在记录的时间解析刺激拉曼光谱中,β-C 拉伸带的 β-胡萝卜素。飞秒时间解析近红外刺激拉曼光谱仪适用于从简单分子到复杂材料的α-偶联系统的结构动力学。
拉曼光谱是一种强大而通用的工具,用于研究从简单气体、液体和固体到功能材料和生物系统的各种样品中的分子结构。当激发光的光子能量与分子的电子过渡能量重合时,拉曼散射会显著增强。共振拉曼效应使我们能够有选择地观察由多种分子组成的样本中的一个物种的拉曼光谱。近红外电子转换作为研究具有大型-共结结构的分子的兴奋状态动力学的探索,引起了人们的广泛关注。最低兴奋单态的能量和寿命已经确定为几种类胡萝卜素,它们具有一维多烯链1,2,3。中性和带电激发动力学已被广泛研究为薄膜4,5,6,7,纳米粒子8和溶液9,10,11的各种光导聚合物。如果对这些系统应用时间解析的近红外拉曼光谱,则可获得有关瞬变结构的详细信息。然而,只有少数研究被报道在时间解析的近红外拉曼光谱12,13,14,15,16,因为近红外拉曼光谱仪的灵敏度极低。低灵敏度主要源于近红外拉曼散射的低概率。自发拉曼散射的概率与 αi=s3成正比,其中 αi和 αs分别是激发光和拉曼散射光的频率。此外,市售的近红外探测器的灵敏度远低于在紫外线和可见区域运行的 CCD 探测器。
飞秒时间解析刺激拉曼光谱已成为一种新的方法来观察拉曼主动振动带的时间依赖性变化,超越激光脉冲17,18,19,20,21,22,23,24,25,26,27,28的明显傅立叶变换极限 ,29,30,31,32,33.刺激的拉曼散射是由两个激光脉冲的辐照产生的:拉曼泵和探针脉冲。这里假定拉曼泵脉冲的频率大于探头脉冲。当拉曼泵和探针脉冲的频率差与拉曼有源分子振动的频率一致时,辐照体积中大量分子的振动是相干激发的。相干分子振动引起的非线性偏振增强了探针脉冲的电场。该技术对于近红外拉曼光谱学特别强大,因为刺激拉曼散射可以解决时间解析的近红外自发拉曼光谱仪的灵敏度问题。刺激的拉曼散射被检测为探头脉冲的强度变化。即使近红外探测器具有低灵敏度,当探头强度充分增加时,也会检测到刺激的拉曼散射。激发拉曼散射的概率与 ±RP=SRS成正比,其中 ±RP和 +SRS是拉曼泵脉冲和刺激拉曼散射的频率,分别为20。刺激拉曼散射、αRP和 +SRS的频率分别相当于自发拉曼散射的 αi和 αs。我们最近开发了一个飞秒时间解析近红外拉曼光谱仪,使用刺激拉曼散射来研究在α-conju系统2、3、7、10中产生的短寿命瞬变光的结构和动力学。在本文中,我们将介绍我们第二次时间解析近红外多路复用刺激拉曼光谱仪的技术细节。介绍了光学对齐、时间解析刺激拉曼光谱的采集以及记录光谱的校准和校正。作为光谱仪的代表性应用,研究了β-胡萝卜素在环苯溶液中的兴奋状态动力学。
1. 电气设备的启动
2. 光谱仪的光学对准
3. 软件操作
4. 探头频谱优化
5. 固定刺激拉曼光谱的测量
6. 时间解析吸收光谱的测量
7. 测量时间解析刺激拉曼光谱
8. 拉曼换档校准
在肌胶溶液中应用了邻IR刺激拉曼光谱法。样品的浓度为1 x10-4摩尔dm-3。样品在480nm的正射泵脉冲下光激发,脉冲能量为1μJ。图2A显示了在图2A中β-胡萝卜素的及时解刺激拉曼光谱。原始光谱含有强拉曼带的溶剂苯和弱拉曼带的β-胡萝卜素在地面状态,以及拉曼带的光兴奋β-胡萝卜素。在光射前1ps处,使用同一溶液的刺激拉曼光谱减去它们。减法?...
飞秒时间解析近红外多路复用中的关键因素刺激了拉曼测量
为了获得具有高信噪比的近IR刺激拉曼光谱,探头光谱最好在整个波长范围内具有均匀的强度。因此,白光连续生成(第2.5节)是时间解析近IR刺激拉曼实验最关键的部分之一。通常,随着射化光束强度的增加,探头光谱变得广泛而平坦。然而,高光束强度很容易产生不需要的非线性光学效应,而不是白光连续生成。在最坏...
作者没有什么可透露的。
这项工作得到了JSPS KAKENHI授权编号JP24750023、JP24350012、MEXT KAKENHI授权编号JP26104534、JP16H00850、JP26102541、JP16H00782和MEXT支持的私立大学战略研究基金会计划的支持,2015-2019年。
Name | Company | Catalog Number | Comments |
1-Axis Translational Stage | OptSigma | TSD-401S | Products equivalent to this are used as well; for M22, L9, and CM in Figure 1A |
20-cm Optical Delay Line | OptSigma | SGSP26-200 | ODL1 in Figure 1A |
3-Axis Translational Stage | OptSigma | TSD-405SL | For L8 in Figure 1A |
3-Axis Translational Stage | Suruga Seiki | B72-40C | For FC in Figure 1A |
5-cm Optical Delay Line | PMT | HRS-0050 | ODL2 in Figure 1A |
Al Concave Mirror | Thorlabs | CM254-050-G01 | Focal length: 50 mm; CM in Figure 1A |
Base Plate | Suruga Seiki | A21-6 | Products equivalent to this are used as well; for M1-M32, BS1-BS3, L1-L10, I1-I17, P1-P2, HWP1-3, F1-F3, VND1-VND2, OC, BPF, HS, BBO, SP, CM, and FC in Figure 1A |
BBO Crystal | EKSMA Optics | - | Type 1, θ = 23.2 deg; BBO in Figure 1A |
BK7 Plano-Concave Lens | OptSigma | SLB-25.4-50NIR2 | Focal length: 50 mm; IR anti-reflection coating; L6 in Figure 1A |
BK7 Plano-Convex Lens | OptSigma | SLB-25.4-150PIR2 | Focal length: 150 mm; IR anti-reflection coating; L2, L3, L5 in Figure 1A |
BK7 Plano-Convex Lens | OptSigma | SLB-25.4-100PIR2 | Focal length: 100 mm; IR anti-reflection coating; L4 in Figure 1A |
BK7 Plano-Convex Lens | OptSigma | SLB-25.4-200PIR2 | Focal length: 200 mm; IR anti-reflection coating; L7 in Figure 1A |
Broadband Dielectric Mirror | OptSigma | TFMS-25.4C05-2/7 | M22-M25, M28, M29 in Figure 1A |
Broadband Dielectric Mirror | Precision Photonics (Advanced Thin Films) | - | M26, M27, M30-M32 in Figure 1A |
Broadband Half-Wave Plate | CryLight | - | HWP3 in Figure 1A |
Color Glass Filter | HOYA | IR85 | F1 in Figure 1A |
Color Glass Filter | HOYA | RM100 | F2 in Figure 1A |
Color Glass Filter | Schott | BG39 | F3 in Figure 1A |
Computer | Dell | Vostro 200 Mini Tower | OS: Windows XP |
Cyclohexane | Kanto Kagaku | 07547-1B | HPLC grade |
Data Analysis Software | Wavemetrics | Igor Pro 8 | |
Dielectric Beamsplitter | LAYERTEC | - | Reflection : Transmission = 2 : 1; BS1 in Figure 1A |
Dielectric Beamsplitter | LAYERTEC | - | Reflection : Transmission = 1 : 1; BS2, BS3 in Figure 1A |
Dielectric Mirror | Precision Photonics (Advanced Thin Films) | - | M1-M8 in Figure 1A |
Digital Oscilloscope | Tektronix | TDS3054B | 500 MHz, 5 GS/s |
Elastomer Tube | - | - | Figure 1E |
Femtosecond Ti:sapphire Oscillator | Coherent | Vitesse 800-2 | Wavelength: 800 nm, pulse duration: 100 fs, average power: 280 mW, repetition rate: 80 MHz; included in Ti:S in Figure 1A |
Femtosecond Ti:sapphire Regenerative Amplifier | Coherent | Legend-Elite-F-HE | Wavelength: 800 nm, pulse duration: 100 fs, pulse energy: 3.5 mJ, repetition rate: 1 kHz; included in Ti:S in Figure 1A |
Film Polarizer | OptSigma | SPFN-30C-26 | P1 in Figure 1A |
Glan-Taylor Prism | OptSigma | GYPB-10-10SN-3/7 | P2 in Figure 1A |
Gold Mirror | OptSigma | TFG-25C05-10 | M9-M21 in Figure 1A |
Half-Wave Plate | OptSigma | WPQ-7800-2M | HWP1 in Figure 1A |
Harmonic Separator | Coherent | TOPAS-C HRs 410-540 nm | HS in Figure 1A |
InGaAs Array Detector | Horiba | Symphony-IGA-512X1-50-1700-1LS | 512 ch, Liquid nitrogen cooled |
InGaAs PIN Photodiode | Hamamatsu Photonics | G10899-01K | |
IR Half-Wave Plate | OptiSource | - | HWP2 in Figure 1A |
Iris | Suruga Seiki | F74-3N | Products equivalent to this are used as well; I1-I17 in Figure 1A |
Lens Holder | OptSigma | LHF-25.4S | Products equivalent to this are used as well; for L1-L10 in Figure 1A |
Magnetic Gear Pump | Micropump | 184-415 | |
Mirror Mount | Siskiyou | IM100.C2M6R | Products equivalent to this are used as well; for M1-M32, BS1-BS3, BBO, CM in Figure 1A |
near-IR phosphor card | Thorlabs | VRC2 | |
Nut | - | - | Figure 1E, M4; purchased from a DIY store |
Optical Chopper | New Focus | 3501 | OC in Figure 1A |
Optical Parametric Amplifier | Coherent | OPerA-F | OPA1 in Figure 1A |
Optical Parametric Amplifier | Coherent | TOPAS-C | OPA2 in Figure 1A |
Polarizer Holder | OptSigma | PH-30-ARS | Products equivalent to this are used as well; for P1-P2 and HWP1-3 In Figure 1A |
Polyfluoroacetate Tube | - | - | Figure 1E |
Post Holder | OptSigma | BRS-12-80 | Products equivalent to this are used as well; for M1-M32, BS1-BS3, L1-L10, I1-I17, P1-P2, HWP1-3, F1-F3, VND1-VND2, OC, BPF, HS, BBO, SP, CM, and FC in Figure 1A |
Quartz Flow Cell | Tosoh Quartz | T-70-UV-2 | FC in Figure 1A |
Quartz Plano-Concave Lens | OptSigma | SLSQ-25-50N | Focal length: 50 mm; L8 in Figure 1A |
Quartz Plano-Convex Lens | OptSigma | SLSQ-25-100P | Focal length: 100 mm; L1, L9 in Figure 1A |
Quartz Plano-Convex Lens | OptSigma | SLSQ-25-220P | Focal length: 220 mm; L10 in Figure 1A |
Sapphire Plate | Pier Optics | - | 3 mm thick; SP in Figure 1A |
Si PIN Photodiode | Hamamatsu Photonics | S3883 | |
Single Spectrograph | Horiba Jobin Yvon | iHR320 | Focal length: 32 cm |
Stainless Steel Rod | Suruga Seiki | A41-100 | Products equivalent to this are used as well; for M1-M32, BS1-BS3, L1-L10, I1-I17, P1-P2, HWP1-3, F1-F3, VND1-VND2, OC, BPF, HS, BBO, SP, CM, and FC in Figure 1A |
Stainless Steel Rod | Newport | J-SP-2 | Figure 1E |
Toluene | Kanto Kagaku | 40180-1B | HPLC grade |
U-Shaped Steel Plate | - | - | Figure 1E; purchased from a DIY store |
Variable Neutral Density Filter (with a holder) | OptSigma | NDHN-100 | VND1 in Figure 1A |
Variable Neutral Density Filter (with a holder) | OptSigma | NDHN-U100 | VND2 in Figure 1A |
Visual Programming Language | National Instruments | LabVIEW 2009 | The control software in this study is programmed in LabVIEW 2009 |
Volume-Grating Bandpass Filter | OptiGrate | BPF-1190 | BPF in Figure 1A |
β-Carotene | Wako Pure Chemical Industries | 035-05531 |
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