Name: direct imaging of laser-driven ultrafast molecular rotation
Uploaded: 2017-02-04T13:00:00.000+00:00
Duration: 10 min 52 s
Description: Watch this Scientific Journal Video about Direct Imaging of Laser-driven Ultrafast Molecular Rotation at JoVE.com

This work was supported in part by grants-in-aid KAKENHI from the Japan Society for the Promotion of Science (JSPS) and the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) Japan (#26104539, #26620020, #26810011, #15H03766, #15KT0060, #16H00826, and #16K13927); the Konica Minolta Science and Technology Foundation; the "Planting Seeds for Research" program of TokyoTech; the Imaging Science Project of the Center for Novel Science Initiatives (CNSI) at the National Institutes of Natural Sciences (NINS) (#IS261006); the RIKEN-IMS joint program on "Extreme Photonics;" and the Consortium for Photon Science and Technology (CPhoST).

<ol>
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The authors have nothing to disclose.

現在の手順では、スリットベースの2D画像のセットアップを分子回転のリアルタイム動画をキャプチャすることを可能にしています。観察されたイオンは、スリットを通過するので、ステップ1.5は重要なステップの1つです。スリット刃のエッジがシャープである必要があります。このようなスリットさ0.3mmの凹みのような小さな欠陥がある場合には、傷をイオン像（ 図6）におい?...

分子の動的な性質をより深く理解し、より良い使用のために、明らかに関心の分子運動を可視化することが不可欠です。時間分解クーロン爆発イメージングは、この対物レンズ1、2、3を得るための強力なアプローチの一つです。このアプローチでは、目的の分子動力学は、ポンプ、超短レーザー場によって開始され、その後、時間遅延プローブパルスによってプローブされます。プローブを照射すると、分子は、多重クーロン反発力に起因するフラグメントイオンにイオン化し、分割されます。排出されたイオンの空間分布は、プローブ照射で分子構造および空間配向の尺度です。ポンプ - プローブ遅延時間をスキャン測定の順序は、分子ムービーの作成につながります。注目すべきは、その最も単純なケースのために - 二原子分子 - 放出されたイオンの角度分布直接分子軸の分布（ すなわち、二乗回転波動関数）を反映しています。 ポンプのプロセスに関しては、超短レーザー場を用いた分子運動のコヒーレント制御における最近の進歩は、高度に制御された回転波束4、5の創出につながっています。また、回転方向を積極的に偏光制御レーザフィールド6、 図7、 図8を用いて制御することができます。従って、クーロン爆発イメージング技術は、例えば、ポンププロセス9、10、11、12、13と組み合わされたときに波の性質を含む分子回転の詳細な画像は、可視化できることが期待されています。しかし、私たちはいくつかの時間は、後述するように、既存のイメージング法に関連した実験的な困難に直面します。本稿の目的は、これらの困難を克服し、分子の回転波束の高品質なムービーを作成するための新しい方法を提示することです。その物理的な意味合いとともに、本発明の方法で撮影された分子回転の最初の実験的な映画は、私たちの前の紙11に提示されました。開発の背景には、現在のイメージング技術の詳細な理論的側面、および他の既存の技術との比較は今後の論文に与えられます。ここでは、主に一般的なポンププローブ光の設定の組み合わせと新しいイメージング装置を含む、手順の実用的かつ技術的な側面に焦点を当てます。前の紙のように、ターゲット・システムは、一方向窒素分子11が回転しています。 の主な実験的な難しさ既存のイメージングセットアップは、 図1に概略的に示され、検出器の位置、またはカメラアングルに関係しています。回転軸は、レーザー電界誘起分子回転レーザ伝搬軸6、7、8と一致するので、回転軸に沿って検出器を設置することは実際的ではありません。レーザー照射を回避するように検出器が設置されている場合、カメラアングルは、回転側の観察に相当します。この場合には、投影された（2D）イオン画像14からの分子の元の向きを再構築することは不可能です。上部検出器とイオンIMPACへと到達時間3次元イメージング検出器14、15、16、17、18、19、Tの位置を測定することができ、クーロン爆発イメージング10,12を使用して、直接分子回転を観察するためのユニークな方法を提供します。しかし、レーザーショットごとに許容されるイオンの数は、高画質14と分子運動の長いムービーを作成することが困難であることを意味し、3次元検出器の低い（典型的には&lt;10イオン）です。検出器（典型的にはナノ秒）のデッドタイムは、画像の解像度と画像化効率に影響を与えます。また、&lt;〜1kHzでのレーザ繰り返し率でリアルタイムイオン画像を監視することにより、良好なポンプ・プローブビームの重なりを作るための簡単な作業ではありません。いくつかのグループが3D技術を用いて、回転波パケットを観察しているが、空間情報は、限られたおよび/または直接的であり、複雑な結節構造を含む波動性の詳細な視覚化、10、12を得られませんでした。 の本質新しいイメージング技術は、 図1の「新しいカメラアングル」の使用です。 2次元検出器は、回転軸方向から観察に至る、回転面に平行であるが、この構成では、検出器へのレーザビーム露光が回避されます。スリットが画像に貢献する回転面（レーザーパルスの偏光面）でのイオンのみを許可します。 3D検出器よりも高い計数率（典型的には約100イオン）を提供する2次元検出器を使用することができます。測定効率が高い一方で電子機器のセットアップは、3D検出の場合よりも簡単です。このようなアベル反転14と時間のかかる数学的再構成は、また、角度情報を抽出するために必要とされません。これらの特徴は、測定システムの容易な最適化、高品質ムービーの生成につながります。標準的な2D / 3D荷電粒子撮像装置は、容易に現在設定withoに修飾することができます高価な機器の使用をユタ。

<table><tbody><tr><td>CMOS camera</td><td>Toshiba TELI</td><td>BU-238M-ES</td><td>equipped with SONY IMX174 sensor</td></tr><tr><td>High voltage switch</td><td>Behlke</td><td>HTS-41-03-GSM</td><td></td></tr><tr><td>High voltage switch</td><td>Behlke</td><td>HTS-80-03</td><td></td></tr><tr><td>Digital delay generator</td><td>Stanford research systems</td><td>DG535</td><td></td></tr><tr><td>Digital delay generator</td><td>Stanford research systems</td><td>DG645</td><td></td></tr><tr><td>Microchannel plate</td><td>Photonis</td><td>3075</td><td></td></tr><tr><td>Pulsed valve</td><td>LAMID LTD</td><td>Even-Lavie valve&amp;nbsp;</td><td>High repetition, room temperature model</td></tr><tr><td>Molecular beam skimmers</td><td>Institute for Molecular Science</td><td>13C11</td><td>3 and 1.5 mm center hole, 25 degrees full inner angle, and ~50 mm length</td></tr><tr><td>Optical Comparator</td><td>Nikon</td><td>V-24B</td><td></td></tr><tr><td>DPSS laser</td><td>Lighthouse Photonics</td><td>Sprout</td><td></td></tr><tr><td>Femtosecond Ti:Sapphire oscillator</td><td>KMLabs</td><td>Halcyon</td><td></td></tr><tr><td>Femtosecond Ti:Sapphire amplifier</td><td>Quantronix</td><td>Odin-II HE</td><td></td></tr><tr><td>Motorized linear stage</td><td>Sigma Koki</td><td>KST(GS)-100X</td><td></td></tr><tr><td>Manual X-stage</td><td>Sigma Koki</td><td>TSD-601S</td><td></td></tr><tr><td>High resolution mirror mount</td><td>Newport</td><td>Suprema SX100-F2KN-254</td><td></td></tr><tr><td>High resolution mirror mount</td><td>LIOP-TEC GmbH</td><td>SR100-100R-2-HS</td><td></td></tr><tr><td>Polarization checker</td><td>Paradigm Devices, Inc.</td><td>O-tool VIS</td><td></td></tr><tr><td>Instrument communication interface</td><td>National Instruments</td><td>NI-MAX</td><td></td></tr><tr><td>Graphical development environment for measurement programs</td><td>National Instruments</td><td>LabVIEW 2014</td><td></td></tr><tr><td>Laser line dielectric mirror</td><td>CVI/LEO</td><td>TLM2-400/800-45UNP</td><td></td></tr><tr><td>Laser line dielectric mirror</td><td>Altechna</td><td>Low GDD Ultrafast mirror</td><td></td></tr><tr><td>Laser line dielectric mirror</td><td>Altechna</td><td>Low GDD Ultrafast mirror</td><td></td></tr><tr><td>Femtosecond polarizer</td><td>Advanced Thin Films</td><td>PBS-GVD</td><td></td></tr></tbody></table>

direct imaging of laser-driven ultrafast molecular rotation

我々は、レーザー誘起、超高速分子の回転波束のダイナミクスを可視化するための方法を提示します。我々は、これまで、非実用的なカメラアングルを実現した新たな2次元クーロン爆発イメージングセットアップを開発しました。我々のイメージング技術では、二原子分子は、円偏光の強いレーザーパルスを照射します。排出された原子イオンは、レーザ伝搬に対して垂直に加速されます。レーザの偏光平面内にあるイオンは、機械的なスリットを使用することによって選択された偏光面と平行に設置高スループット、2次元検出器で画像化されます。円偏光（等方性）クーロン爆発パルスを用いているため、排出されたイオンの観察角度分布は、直接パルス照射時の二乗回転波動関数に相当します。分子回転のリアルタイム動画を作成するために、現在のイメージング技術は、フェムト秒ポンプ - プローブOと組み合わされポンプパルスが一方向分子アンサンブルを回転作成するpticalセットアップ。我々の検出システムの高い画像処理能力に、ポンププローブ実験条件は、容易にリアルタイムスナップショットを監視することによって最適化することができます。その結果、観察映画の品質は、動きの詳細な波動性を可視化するために十分に高いです。また、大規模な変更を必要とすることなく、分子システムのための新しいカメラアングルや視点を提供し、本技術は、既存の標準イオンイメージングセットアップで実現することができることに注意してください。

図4Aに示すN 2+イオンのプローブ専用のRAW画像は、1プローブレーザショットのために採取プローブ照射（クーロン爆発）、時に排出されます。明るいスポットは一つのイオンに対応します。 図4Bは、万二値化し、生のカメラ画像の積算画像を示しています。これらの画像は、私たちのイメージングセットアップが偏光面内のすべ?...

Watch this Scientific Journal Video about Direct Imaging of Laser-driven Ultrafast Molecular Rotation at JoVE.com

Direct Imaging of Laser-driven Ultrafast Molecular Rotation

We present a protocol for creating a real-time movie of a molecular rotational wave packet using a high-resolution Coulomb explosion imaging setup.

レーザー駆動の超高速分子回転のダイレクトイメージング

We present a method for visualizing laser-induced, ultrafast molecular rotational wave packet dynamics. We have developed a new 2-dimensional Coulomb ...

direct-imaging-of-laser-driven-ultrafast-molecular-rotation

Universidad San Sebastian

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Chemistry

Chemical Bonding: Molecular Geometry and Bonding Theories

SCIENTISTS IN ACTION

9.6K ビュー.  Tokyo Institute of Technology. We present a protocol for creating a real-time movie of a molecular rotational wave packet using a high-resolution Coulomb explosion imaging setup.

ビデオ: Direct Imaging of Laser-driven Ultrafast Molecular Rotation

Fluorescence Lifetime Imaging of Molecular Rotors in Living Cells

Diffusion is often an important rate-determining step in chemical reactions or biological processes and plays a role in a wide range of intracellular events. Viscosity is one of the key parameters affecting the diffusion of molecules and proteins, and changes in viscosity have been linked to disease and malfunction at the cellular level.1-3 While methods to measure the bulk viscosity are well developed, imaging microviscosity remains a challenge. Viscosity maps of microscopic objects, such as single cells, have until recently been hard to obtain. Mapping viscosity with fluorescence techniques is advantageous because, similar to other optical techniques, it is minimally invasive, non-destructive and can be applied to living cells and tissues.
Fluorescent molecular rotors exhibit fluorescence lifetimes and quantum yields which are a function of the viscosity of their microenvironment.4,5 Intramolecular twisting or rotation leads to non-radiative decay from the excited state back to the ground state. A viscous environment slows this rotation or twisting, restricting access to this non-radiative decay pathway. This leads to an increase in the fluorescence quantum yield and the fluorescence lifetime. Fluorescence Lifetime Imaging (FLIM) of modified hydrophobic BODIPY dyes that act as fluorescent molecular rotors show that the fluorescence lifetime of these probes is a function of the microviscosity of their environment.6-8 A logarithmic plot of the fluorescence lifetime versus the solvent viscosity yields a straight line that obeys the F&ouml;rster Hoffman equation.9 This plot also serves as a calibration graph to convert fluorescence lifetime into viscosity.
Following incubation of living cells with the modified BODIPY fluorescent molecular rotor, a punctate dye distribution is observed in the fluorescence images. The viscosity value obtained in the puncta in live cells is around 100 times higher than that of water and of cellular cytoplasm.6,7 Time-resolved fluorescence anisotropy measurements yield rotational correlation times in agreement with these large microviscosity values. Mapping the fluorescence lifetime is independent of the fluorescence intensity, and thus allows the separation of probe concentration and viscosity effects. 
In summary, we have developed a practical and versatile approach to map the microviscosity in cells based on FLIM of fluorescent molecular rotors.

Fluorescence Lifetime Imaging (FLIM) has emerged as a key technique to image the environment and interaction of specific proteins and dyes in living cells. FLIM of fluorescent molecular rotors allows mapping of viscosity in living cells.

生細胞における分子ローターの蛍光寿命イメージング

Diffusion is often an important rate-determining step in chemical reactions or biological processes and plays a role in a wide range of intracellular ...

生物工学

Spatial Separation of Molecular Conformers and Clusters

Gas-phase molecular physics and physical chemistry experiments commonly use supersonic expansions through pulsed valves for the production of cold molecular beams. However, these beams often contain multiple conformers and clusters, even at low rotational temperatures. We present an experimental methodology that allows the spatial separation of these constituent parts of a molecular beam expansion. Using an electric deflector the beam is separated by its mass-to-dipole moment ratio, analogous to a bender or an electric sector mass spectrometer spatially dispersing charged molecules on the basis of their mass-to-charge ratio. This deflector exploits the Stark effect in an inhomogeneous electric field and allows the separation of individual species of polar neutral molecules and clusters. It furthermore allows the selection of the coldest part of a molecular beam, as low-energy rotational quantum states generally experience the largest deflection. Different structural isomers (conformers) of a species can be separated due to the different arrangement of functional groups, which leads to distinct dipole moments. These are exploited by the electrostatic deflector for the production of a conformationally pure sample from a molecular beam. Similarly, specific cluster stoichiometries can be selected, as the mass and dipole moment of a given cluster depends on the degree of solvation around the parent molecule. This allows experiments on specific cluster sizes and structures, enabling the systematic study of solvation of neutral molecules.

We present a technique that allows the spatial separation of different conformers or clusters present in a molecular beam. An electrostatic deflector is used to separate species by their mass-to-dipole moment ratio, leading to the production of gas-phase ensembles of a single conformer or cluster stoichiometry.

分子適合体とクラスターの空間的分離

Gas-phase molecular physics and physical chemistry experiments commonly use supersonic expansions through pulsed valves for the production of cold ...

工学

Characterizing Far-infrared Laser Emissions and the Measurement of Their Frequencies

The generation and subsequent measurement of far-infrared radiation has found numerous applications in high-resolution spectroscopy, radio astronomy, and Terahertz imaging. For about 45 years, the generation of coherent, far-infrared radiation has been accomplished using the optically pumped molecular laser. Once far-infrared laser radiation is detected, the frequencies of these laser emissions are measured using a three-laser heterodyne technique. With this technique, the unknown frequency from the optically pumped molecular laser is mixed with the difference frequency between two stabilized, infrared reference frequencies. These reference frequencies are generated by independent carbon dioxide lasers, each stabilized using the fluorescence signal from an external, low pressure reference cell. The resulting beat between the known and unknown laser frequencies is monitored by a metal-insulator-metal point contact diode detector whose output is observed on a spectrum analyzer. The beat frequency between these laser emissions is subsequently measured and combined with the known reference frequencies to extrapolate the unknown far-infrared laser frequency. The resulting one-sigma fractional uncertainty for laser frequencies measured with this technique is &#177; 5 parts in 107. Accurately determining the frequency of far-infrared laser emissions is critical as they are often used as a reference for other measurements, as in the high-resolution spectroscopic investigations of free radicals using laser magnetic resonance. As part of this investigation, difluoromethane, CH2F2, was used as the far-infrared laser medium. In all, eight far-infrared laser frequencies were measured for the first time with frequencies ranging from 0.359 to 1.273 THz. Three of these laser emissions were discovered during this investigation and are reported with their optimal operating pressure, polarization with respect to the CO2 pump laser, and strength.

We describe the generation of far-infrared radiation using an optically pumped molecular laser along with the measurement of their frequencies with heterodyne techniques. The experimental system and techniques are demonstrated using difluoromethane (CH2F2) as the laser medium whose results include three new laser emissions and eight measured laser frequencies.

遠赤外線レーザーの排出量とその周波数の測定を特徴付けます

The generation and subsequent measurement of far-infrared radiation has found numerous applications in high-resolution spectroscopy, radio astronomy, and ...

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers

This article shows how the COLTRIMS (Cold Target Recoil Ion Momentum Spectroscopy) or the "reaction microscope" technique can be used to distinguish between enantiomers (stereoisomers) of simple chiral species on the level of individual molecules. In this approach, a gaseous molecular jet of the sample expands into a vacuum chamber and intersects with femtosecond (fs) laser pulses. The high intensity of the pulses leads to fast multiple ionization, igniting a so-called Coulomb Explosion that produces several cationic (positively charged) fragments. An electrostatic field guides these cations onto time- and position-sensitive detectors. Similar to a time-of-flight mass spectrometer, the arrival time of each ion yields information on its mass. As a surplus, the electrostatic field is adjusted in a way that the emission direction and the kinetic energy after fragmentation lead to variations in the time-of-flight and in the impact position on the detector.
Each ion impact creates an electronic signal in the detector; this signal is treated by high-frequency electronics and recorded event by event by a computer. The registered data correspond to the impact times and positions. With these data, the energy and the emission direction of each fragment can be calculated. These values are related to structural properties of the molecule under investigation, i.e. to the bond lengths and relative positions of the atoms, allowing to determine molecule by molecule the handedness of simple chiral species and other isomeric features.

For small chiral species, Coulomb Explosion Imaging provides a new approach to determine the handedness of individual molecules.

立体異性体を区別するためのツールとしてクーロン爆発イメージング

This article shows how the COLTRIMS (Cold Target Recoil Ion Momentum Spectroscopy) or the "reaction microscope" technique can be used to distinguish ...

化学

Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving

We present a cooling method for a cold Fermi gas by parametrically driving atomic motions in a crossed-beam optical dipole trap (ODT). Our method employs the anharmonicity of the ODT, in which the hotter atoms at the edge of the trap feel the anharmonic components of the trapping potential, while the colder atoms in the center of the trap feel the harmonic one. By modulating the trap depth with frequencies that are resonant with the anharmonic components, we selectively excite the hotter atoms out of the trap while keeping the colder atoms in the trap, generating parametric cooling. This experimental protocol starts with a magneto-optical trap (MOT) that is loaded by a Zeeman slower. The precooled atoms in the MOT are then transferred to an ODT, and a bias magnetic field is applied to create an interacting Fermi gas. We then lower the trapping potential to prepare a cold Fermi gas near the degenerate temperature. After that, we sweep the magnetic field to the noninteracting regime of the Fermi gas, in which the parametric cooling can be manifested by modulating the intensity of the optical trapping beams. We find that the parametric cooling effect strongly depends on the modulation frequencies and amplitudes. With the optimized frequency and amplitude, we measure the dependence of the cloud energy on the modulation time. We observe that the cloud energy is changed in an anisotropic way, where the energy of the axial direction is significantly reduced by parametric driving. The cooling effect is limited to the axial direction because the dominant anharmonicity of the crossed-beam ODT is along the axial direction. Finally, we propose to extend this protocol for the trapping potentials of large anharmonicity in all directions, which provides a promising scheme for cooling quantum gases using external driving.

We present a parametric driving method to cool an ultracold Fermi gas in a crossed-beam optical dipole trap. This method selectively removes high-energy atoms from the trap by periodically modulating the trap depth with frequencies that are resonant with the anharmonic components of the trapping potential.

定期駆動することによって光学的に閉じ込められた超低温フェルミガスを冷却

We present a cooling method for a cold Fermi gas by parametrically driving atomic motions in a crossed-beam optical dipole trap (ODT). Our method employs ...

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals

We discuss in this article the experimental measurements of the molecules in liquid crystal (LC) phase using the time-resolved infrared (IR) vibrational spectroscopy and time-resolved electron diffraction. Liquid crystal phase is an important state of matter that exists between the solid and liquid phases and it is common in natural systems as well as in organic electronics. Liquid crystals are orientationally ordered but loosely packed, and therefore, the internal conformations and alignments of the molecular components of LCs can be modified by external stimuli. Although advanced time-resolved diffraction techniques have revealed picosecond-scale molecular dynamics of single crystals and polycrystals, direct observations of packing structures and ultrafast dynamics of soft materials have been hampered by blurry diffraction patterns. Here, we report time-resolved IR vibrational spectroscopy and electron diffractometry to acquire ultrafast snapshots of a columnar LC material bearing a photoactive core moiety. Differential-detection analyses of the combination of time-resolved IR vibrational spectroscopy and electron diffraction are powerful tools for characterizing structures and photoinduced dynamics of soft materials.

Here, we present the protocols of differential-detection analyses of time-resolved infrared vibrational spectroscopy and electron diffraction which enable observations of the deformations of local structures around photoexcited molecules in a columnar liquid crystal, giving an atomic perspective on the relationship between the structure and the dynamics of this photoactive material.

光応答性液晶の構造ダイナミクスを観察する手法

We discuss in this article the experimental measurements of the molecules in liquid crystal (LC) phase using the time-resolved infrared (IR) vibrational ...

Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization

We present a pump-probe method for preparing vibrational coherences in polyatomic radical cations and probing their ultrafast dynamics. By shifting the wavelength of the strong-field ionizing pump pulse from the commonly used 800 nm into the near-infrared (1200-1600 nm), the contribution of adiabatic electron tunneling to the ionization process increases relative to multiphoton absorption. Adiabatic ionization results in predominant population of the ground electronic state of the ion upon electron removal, which effectively prepares a coherent vibrational state (&#34;wave packet&#34;) amenable to subsequent excitation. In our experiments, the coherent vibrational dynamics are probed with a weak-field 800 nm pulse and the time-dependent yields of dissociation products measured in a time-of-flight mass spectrometer. We present the measurements on the molecule dimethyl methylphosphonate (DMMP) to illustrate how using 1500 nm pulses for excitation enhances the amplitude of coherent oscillations in ion yields by a factor of 10 as compared to 800 nm pulses. This protocol may be implemented in existing pump-probe setups through the incorporation of an optical parametric amplifier (OPA) for wavelength conversion.

We present a protocol for probing ultrafast vibrational coherences in polyatomic radical cations that result in molecular dissociation.

強いフィールド断熱イオンとラジカル陽イオン多原子の超高速振動コヒーレンスの測定

We present a pump-probe method for preparing vibrational coherences in polyatomic radical cations and probing their ultrafast dynamics. By shifting the ...

Construction and Operation of a Light-driven Gold Nanorod Rotary Motor System

The possibility to generate and measure rotation and torque at the nanoscale is of fundamental interest to the study and application of biological and artificial nanomotors and may provide new routes towards single cell analysis, studies of non-equilibrium thermodynamics, and mechanical actuation of nanoscale systems. A facile way to drive rotation is to use focused circularly polarized laser light in optical tweezers. Using this approach, metallic nanoparticles can be operated as highly efficient scattering-driven rotary motors spinning at unprecedented rotation frequencies in water.
In this protocol, we outline the construction and operation of circularly-polarized optical tweezers for nanoparticle rotation and describe the instrumentation needed for recording the Brownian dynamics and Rayleigh scattering of the trapped particle. The rotational motion and the scattering spectra provides independent information on the properties of the nanoparticle and its immediate environment. The experimental platform has proven useful as a nanoscopic gauge of viscosity and local temperature, for tracking morphological changes of nanorods and molecular coatings, and as a transducer and probe of photothermal and thermodynamic processes.

Plasmonic gold nanorods can be trapped in liquids and rotated at kHz frequencies using circularly-polarized optical tweezers. Introducing tools for Brownian dynamics analysis and light scatteringspectroscopy leads to a powerful system for research and application in numerous fields of science.

金ナノロッドの光駆動ロータリー モーター システムの構築と運用

The possibility to generate and measure rotation and torque at the nanoscale is of fundamental interest to the study and application of biological and ...

Light-driven Molecular Motors on Surfaces for Single Molecular Imaging

The design and synthesis of a synthetic system that aims for the direct visualization of a synthetic rotary motor at the single molecule level on surfaces are demonstrated. This work requires careful design, considerable synthetic effort, and proper analysis. The rotary motion of the molecular motor in solution is shown by 1H NMR and UV-vis absorption spectroscopy techniques. In addition, the method to graft the motor onto an amine-coated quartz is described. This method helps to gain more insight into molecular machines.

The manuscript describes how to synthesize and graft a molecular motor on surfaces for single molecular imaging.

単一分子イメージングの表面上の光駆動の分子モーター

The design and synthesis of a synthetic system that aims for the direct visualization of a synthetic rotary motor at the single molecule level on surfaces ...

Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing

We present a protocol for performing gas spectroscopy using infrared degenerated four-wave mixing (IR-DFWM), for the quantitative detection of gas species in the ppm-to-single-percent range. The main purpose of the method is the spatially resolved detection of low-concentration species, which have no transitions in the visible or near-IR spectral range that could be used for detection. IR-DFWM is a nonintrusive method, which is a great advantage in combustion research, as inserting a probe into a flame can change it drastically. The IR-DFWM is combined with upconversion detection. This detection scheme uses sum-frequency generation to move the IR-DFWM signal from the mid-IR to the near-IR region, to take advantage of the superior noise characteristics of silicon-based detectors. This process also rejects most of the thermal background radiation. The focus of the protocol presented here is on the proper alignment of the IR-DFWM optics and on how to align an intracavity upconversion detection system.

Here, we present a protocol to perform sensitive, spatially resolved gas spectroscopy in the mid-infrared region, using degenerate four-wave mixing combined with upconversion detection.

定量のガスを検知用アップコン バージョン検知赤外線縮退四光波混合

We present a protocol for performing gas spectroscopy using infrared degenerated four-wave mixing (IR-DFWM), for the quantitative detection of gas species ...

レーザー駆動の超高速分子回転のダイレクトイメージング

要約

さらに動画を探す

この動画の章

生細胞における分子ローターの蛍光寿命イメージング

分子適合体とクラスターの空間的分離

遠赤外線レーザーの排出量とその周波数の測定を特徴付けます

立体異性体を区別するためのツールとしてクーロン爆発イメージング

定期駆動することによって光学的に閉じ込められた超低温フェルミガスを冷却

光応答性液晶の構造ダイナミクスを観察する手法

強いフィールド断熱イオンとラジカル陽イオン多原子の超高速振動コヒーレンスの測定

金ナノロッドの光駆動ロータリーモーターシステムの構築と運用

単一分子イメージングの表面上の光駆動の分子モーター

定量のガスを検知用アップコンバージョン検知赤外線縮退四光波混合

レーザー駆動の超高速分子回転のダイレクトイメージング

要約

さらに動画を探す

この動画の章

生細胞における分子ローターの蛍光寿命イメージング

分子適合体とクラスターの空間的分離

遠赤外線レーザーの排出量とその周波数の測定を特徴付けます

立体異性体を区別するためのツールとしてクーロン爆発イメージング

定期駆動することによって光学的に閉じ込められた超低温フェルミガスを冷却

光応答性液晶の構造ダイナミクスを観察する手法

強いフィールド断熱イオンとラジカル陽イオン多原子の超高速振動コヒーレンスの測定

金ナノロッドの光駆動ロータリー モーター システムの構築と運用

単一分子イメージングの表面上の光駆動の分子モーター

定量のガスを検知用アップコン バージョン検知赤外線縮退四光波混合

金ナノロッドの光駆動ロータリーモーターシステムの構築と運用

定量のガスを検知用アップコンバージョン検知赤外線縮退四光波混合