Name: measurement of x-ray beam coherence along multiple directions using 2-d checkerboard phase grating
Uploaded: 2016-10-11T13:00:00.000+00:00
Duration: 10 min 39 s
Description: Watch this Scientific Journal Video about Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating at JoVE.com

Use of the Advanced Photon Source and Center for Nanoscale Materials, Office of Science User Facilities operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357. We acknowledge Dr. Han Wen, NHLBI / National Institutes of Health, Bethesda, MD 20892, USA, for many helpful suggestions during the data processing.

<ol>
	<li>Als-Nielsen, J., McMorrow, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Elements of Modern X-ray Physics. , (2011).</li><li>Born, M., Wolf, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Principle of Optics. , (1999).</li><li>Lin, J. J. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+the+Spatial+Coherence+Function+of+Undulator+Radiation+using+a+Phase+Mask.">Measurement of the Spatial Coherence Function of Undulator Radiation using a Phase Mask.</a> Phys. Rev. Lett. 90 (7), 074801 (2003).</li><li>Cloetens, P., Guigay, J. P., De Martino, C., Baruchel, J., Schlenker, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fractional+Talbot+imaging+of+phase+gratings+with+hard+X-rays.">Fractional Talbot imaging of phase gratings with hard X-rays.</a> Opt. Lett. 22 (14), 1059-1061 (1997).</li><li>Guigay, J. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+partial+Talbot+effect+and+its+use+in+measuring+the+coherence+of+synchrotron+X-rays.">The partial Talbot effect and its use in measuring the coherence of synchrotron X-rays.</a> J. Synchrotron Rad. 11, 476-482 (2004).</li><li>Kluender, R., Masiello, F., Vaerenbergh, P. V., H&#228;rtwig, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+the+spatial+coherence+of+synchrotron+beams+using+the+Talbot+effect.">Measurement of the spatial coherence of synchrotron beams using the Talbot effect.</a> Phys. Status Solidi A. 206 (8), 1842-1845 (2009).</li><li>Pfeiffer, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shearing+Interferometer+for+Quantifying+the+Coherence+of+Hard+X-Ray+Beams.">Shearing Interferometer for Quantifying the Coherence of Hard X-Ray Beams.</a> Phys. Rev. Lett. 94 (1-4), 164801 (2005).</li><li>Marathe, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probing+transverse+coherence+of+x-ray+beam+with+2-D+phase+grating+interferometer.">Probing transverse coherence of x-ray beam with 2-D phase grating interferometer.</a> Opt. Express. 22 (12), 14041-14053 (2014).</li><li>Shi, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Circular+grating+interferometer+for+mapping+transverse+coherence+area+of+X-ray+beams.">Circular grating interferometer for mapping transverse coherence area of X-ray beams.</a> Appl. Phys. Lett. 105 (1-6), 041116 (2014).</li><li>Zanette, I., David, C., Rutishauser, S., Weitkamp, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=2D+grating+simulation+for+X-ray+phase-contrast+and+dark-field+imaging+with+a+Talbot+interferometer.">2D grating simulation for X-ray phase-contrast and dark-field imaging with a Talbot interferometer.</a> , 73-79 (2010).</li></ol>

The authors have nothing to disclose.

図5は、4つのすべての方向に沿った推定横コヒーレンス長を示しています。明らかに、90°方向を0°方向に比べてθ高いξを持っています。ビームライン光学格子の相対位置でのビームの干渉性にほとんど影響を有するので、測定されたコヒーレンス領域は、ソースサイズ面積に反比例します。提示されたX線ビームのコヒーレンス測定技術は、垂直方向（参照...

このようなANL、レモント、IL、USA（http://www.aps.anl.gov）でAPSなどの第三世代の硬X線シンクロトロン放射源は、X線科学の発展に多大な影響を与えています。シンクロトロン放射源は、電子のような荷電粒子は、円軌道に光速近くに移動させるX線の波長、赤外線から、電磁放射のスペクトルを生成します。これらのソースは、高輝度、パルス及びピコ秒のタイミング構造、大きな空間的及び時間的コヒーレンスのような非常に独特の特性を有しています。 X線ビームの空間的コヒーレンスは、第3および第4の世代のシンクロトロン源の重要なパラメータであり、このプロパティを利用した実験の数は劇的に過去20年間1上に増加しています。このようなAPS蓄積リングのために計画されたマルチベンドアクロマート（MBA）格子としてこれらのソースの将来のアップグレードは、劇的に光コヒーレントフラックス（HTTPを増加します：//www.aps.anl.gov/Upgrade/）。 X線ビームは、より高い時間的コヒーレンスを達成するために、結晶モノクロメーターを使用して調整することができます。シンクロトロン光源の横方向コヒーレンスが低いため、電子ビームのエミッタンスおよび実験局へのソースからの長い伝搬距離の実験室ベースのX線源のそれよりも有意に高いです。 通常は、ヤングのピンホール二重または二重スリット実験は、干渉縞2の視認性の検査を通ったビームの空間的コヒーレンスを測定するために使用されます。完全な複雑なコヒーレンス関数（CCF）を得るためには、体系的な測定は、特に硬X線のため、面倒であり、現実的ではない、様々な分離と異なる位置に配置された2つのスリットで必要とされています。均一冗長アレイ（URA）は、位相シフトマスク3として用いることにより、ビームのコヒーレンス測定にも使用することができます。技術は完全なCCFを提供することができるが、それはモデルフリーではありません。さらに最近では、タルボ効果に基づく干渉技術は、定期的なオブジェクトの自己イメージングプロパティを使用して開発されました。これらの干渉計は、ビームの横方向のコヒーレンス4-9を得るための格子の下流少数自己像の距離で測定されたインターフェログラムの可視性を利用します。 2格子システムを使用して横方向コヒーレンスの測定も7が報告されています。 同時に垂直方向と水平方向に沿って、横方向のビームコヒーレンスのマッピングは、最初JP Guigay らによって報告された。5。最近では、APSの光学グループ、X線科学部門（XSD）、中の科学者は、ビームを測定するために、2つの新しい技術を報告している二つの方法用いて同時に二つ以上の方向に沿ってコヒーレンスを横切る：8格子市松相と1、および他の円形相は9格子付き。 本論文ではmeasurementおよびデータ分析手順が、0°に沿って同時に、水平方向に対して45°、90°、135°方向を、ビームの横方向の一貫性を得るために記載されています。測定は、格子市松π/ 2相とAPSの1-BMビームラインで行いました。プロトコルセクションに記載されているこの技術の詳細は、次のとおりです。実験の1）計画。 2）格子2次元市松相の調製。シンクロトロン施設で3）実験のセットアップとアライメント; 4）コヒーレンス測定を行います。 5）データ解析。また、代表的な結果は、技術を説明するために示されています。これらの手順は、格子の設計に最小限の変更で多くの放射光ビームラインで行うことができます。

<table><tbody><tr><td>1-BM-B bending magnet X-ray source</td><td>Advanced photon Source/ Argonne National Lab</td><td></td><td>&lt;a href=&quot;http://www.aps.anl.gov/Xray_Science_Division/Optics/Beamline/&quot;&gt;http://www.aps.anl.gov/Xray_Science_Division/Optics/Beamline/&lt;/a&gt;</td></tr><tr><td>LYSO Scintillator</td><td>Proteus Inc</td><td></td><td>&lt;a href=&quot;http://www.apace-science.com/proteus/lyso.htm#top&quot;&gt;http://www.apace-science.com/proteus/lyso.htm#top&lt;/a&gt;</td></tr><tr><td>Coolsnap HQ2 CCD detector</td><td>Photometrics</td><td></td><td>&lt;a href=&quot;http://www.photometrics.com/products/ccdcams/coolsnap_hq2.php&quot;&gt;http://www.photometrics.com/products/ccdcams/coolsnap_hq2.php&lt;/a&gt;</td></tr><tr><td>ATC 2000 UHV sputtering deposition system</td><td>AJA International Inc</td><td></td><td>&lt;a href=&quot;http://www.ajaint.com/systems_atc.htm&quot;&gt;http://www.ajaint.com/systems_atc.htm&lt;/a&gt;</td></tr><tr><td>MICROPOSIT S1800 photoresist</td><td>Dow&amp;nbsp;</td><td></td><td></td></tr><tr><td>MICROPOSIT 351 developer</td><td>Dow&amp;nbsp;</td><td></td><td></td></tr><tr><td>MA/BA6 lithography system</td><td>SUSS MicroTec</td><td></td><td>&lt;a href=&quot;http://www.suss.com/en/products-solutions/products/mask-aligner/maba6/overview.html&quot;&gt;http://www.suss.com/en/products-solutions/products/mask-aligner/maba6/overview.html&lt;/a&gt;</td></tr><tr><td>Spin coater WS-400-6NPPB</td><td>Laurell Technologies Corporation</td><td></td><td>&lt;a href=&quot;http://www.laurell.com/spin-coater/?model=WS-400-6NPP-LITE&quot;&gt;http://www.laurell.com/spin-coater/?model=WS-400-6NPP-LITE&lt;/a&gt;</td></tr><tr><td>JBX-9300FS electron beam lithography system</td><td>JEOL</td><td></td><td>&lt;a href=&quot;http://www.jeolusa.com/PRODUCTS/PhotomaskDirectWriteLithography/ElectronBeamLithography/JBX-9500FS/tabid/245/Default.aspx&quot;&gt;http://www.jeolusa.com/PRODUCTS/PhotomaskDirectWriteLithography/ElectronBeamLithography/JBX-9500FS/tabid/245/Default.aspx&lt;/a&gt;</td></tr><tr><td>CS-1701 RIE system</td><td>Nordson March</td><td></td><td>&lt;a href=&quot;http://www.nordson.com/EN-US/DIVISIONS/MARCH/PRODUCTS/LEGACY/Pages/CS-1701-Anisotropic-RIE-Plasma-System.aspx&quot;&gt;http://www.nordson.com/EN-US/DIVISIONS/MARCH/PRODUCTS/LEGACY/Pages/CS-1701-Anisotropic-RIE-Plasma-System.aspx&lt;/a&gt;</td></tr><tr><td>Techni Gold 25E</td><td>Technic</td><td></td><td>&lt;a href=&quot;http://www.technic.com/eu/applications/industrial/industrial-chemistry/plating-chemistry&quot;&gt;http://www.technic.com/eu/applications/industrial/industrial-chemistry/plating-chemistry&lt;/a&gt;</td></tr><tr><td>Dektak-8 surface profiler</td><td>Bruker</td><td></td><td>&lt;a href=&quot;http://brukersupport.com/ProductDetail/1136&quot;&gt;http://brukersupport.com/ProductDetail/1136&lt;/a&gt;</td></tr><tr><td>MICROPOSIT 1165 remover</td><td>Dow&amp;nbsp;</td><td></td><td></td></tr></tbody></table>

measurement of x-ray beam coherence along multiple directions using 2-d checkerboard phase grating

技術のための手順は、格子干渉計が報告されている単相を用いた放射光X線源の横方向コヒーレンスを測定します。測定は、アルゴンヌ国立研究所（ANL）で光量子ソース（APS）の1-BM偏向電磁石ビームラインで実証されました。 2-Dの市松π/ 2位相シフト回折格子を使用することによって、横方向コヒーレンス長は、垂直方向及び水平方向に沿って同様に水平方向に45°、135°方向に沿って得られました。本稿で指定された技術的な詳細に続いて、インターフェログラムは、ビーム伝搬方向に沿って位相格子の下流の異なる位置で測定しました。各インターフェログラムの可視性の値は、そのフーリエ変換像における高調波のピークを分析から抽出しました。従って、各方向に沿ったコヒーレンス長は、回折格子対detecの関数としての視認性の進化から抽出することができますTORの距離。四方向におけるコヒーレンス長の同時測定は、ガウス状のX線源のコヒーレンス領域の楕円形状を特定する助け。複数方向のコヒーレンス特性評価のための報告された技術は、適切なサンプルサイズと向きを選択するだけでなく、一貫性の散乱実験での部分的なコヒーレンス効果を補正するために重要です。この技術は、X線光学系の一貫性維持能力を評価するために適用することができます。

詳細な実験とシミュレーションの結果は、上記の測定とデータ解析の手順を説明するために、結果を選択した他の場所8、このセクションは唯一のショーを見ることができるが。 図1 APS 1-BM-Bのビームラインでの実験のセットアップを表します。ビームサイズは、二結晶モノクロメーター（DCM）及び偏向電磁石電源25メートル上流に配置された1×1 mm 2のスリットによ...

Watch this Scientific Journal Video about Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating at JoVE.com

Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating

測定プロトコル及びデータ解析手順は、同時に格子単一2次元チェッカーボード相を使用して、4つの方向に沿って放射光X線源の横方向コヒーレンスを得るために与えられます。この単純な技術は、X線源及びX線光学系の完全な横方向コヒーレンス特性評価に適用することができます。

2次元チェッカーボード位相格子を使用して複数の方向に沿ってX線ビームコヒーレンスの測定

A procedure for a technique to measure the transverse coherence of synchrotron radiation X-ray sources using a single phase grating interferometer is ...

measurement-x-ray-beam-coherence-along-multiple-directions-using-2-d

Research

JoVE Journal

Engineering

9.6K ビュー.  Argonne National Laboratory. 測定プロトコル及びデータ解析手順は、同時に格子単一2次元チェッカーボード相を使用して、4つの方向に沿って放射光X線源の横方向コヒーレンスを得るために与えられます。この単純な技術は、X線源及びX線光学系の完全な横方向コヒーレンス特性評価に適用することができます。 

ビデオ: Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating

Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing

The application of femtosecond four-wave mixing to the study of fundamental properties of diluted magnetic semiconductors ((s,p)-d hybridization, spin-flip scattering) is described, using experiments on GaMnAs as a prototype III-Mn-V system.&#160; Spectrally-resolved and time-resolved experimental configurations are described, including the use of zero-background autocorrelation techniques for pulse optimization.&#160; The etching process used to prepare GaMnAs samples for four-wave mixing experiments is also highlighted.&#160; The high temporal resolution of this technique, afforded by the use of short (20 fsec) optical pulses, permits the rapid spin-flip scattering process in this system to be studied directly in the time domain, providing new insight into the strong exchange coupling responsible for carrier-mediated ferromagnetism.&#160; We also show that spectral resolution of the four-wave mixing signal allows one to extract clear signatures of (s,p)-d hybridization in this system, unlike linear spectroscopy techniques.&#160;&#160; This increased sensitivity is due to the nonlinearity of the technique, which suppresses defect-related contributions to the optical response. This method may be used to measure the time scale for coherence decay (tied to the fastest scattering processes) in a wide variety of semiconductor systems of interest for next generation electronics and optoelectronics.

The technique of femtosecond four-wave mixing is described, including spectrally-resolved and time-resolved configurations. We illustrate the utility of this technique for the investigation of crucial physical properties in the III-V diluted magnetic semiconductors, afforded by its nonlinearity and high temporal resolution.

フェムト秒四光波混合を用いてのGaMnAsコヒーレンス崩壊の測定

The application of femtosecond four-wave mixing to the study of fundamental properties of diluted magnetic semiconductors ((s,p)-d hybridization, ...

工学

Controlled Synthesis and Fluorescence Tracking of Highly Uniform Poly(N-isopropylacrylamide) Microgels

Stimuli-sensitive poly(N-isopropylacrylamide) (PNIPAM) microgels have various prospective practical applications and uses in fundamental research. In this work, we use single particle tracking of fluorescently labeled PNIPAM microgels as a showcase for tuning microgel size by a rapid non-stirred precipitation polymerization procedure. This approach is well suited for prototyping new reaction compositions and conditions or for applications that do not require large amounts of product. Microgel synthesis, particle size and structure determination by dynamic and static light scattering are detailed in the protocol. It is shown that the addition of functional comonomers can have a large influence on the particle nucleation and structure. Single particle tracking by wide-field fluorescence microscopy allows for an investigation of the diffusion of labeled tracer microgels in a concentrated matrix of non-labeled microgels, a system not easily investigated by other methods such as dynamic light scattering.

Controlled Synthesis and Fluorescence Tracking of Highly Uniform PolyN-isopropylacrylamide Microgels

Non-stirred precipitation polymerization provides a rapid, reproducible prototyping approach to the synthesis of stimuli-sensitive poly(N-isopropylacrylamide) microgels of narrow size distribution. In this protocol synthesis, light scattering characterization and single particle fluorescence tracking of these microgels in a wide-field microscopy setup are demonstrated.

制御された合成および均一性の高いポリの蛍光トラッキング（<em&gt; N</em&gt; -isopropylacrylamide）ミクロゲル

Stimuli-sensitive poly(N-isopropylacrylamide) (PNIPAM) microgels have various prospective practical applications and uses in fundamental research. In this ...

化学

Measurement of Quantum Interference in a Silicon Ring Resonator Photon Source

Silicon photonic chips have the potential to realize complex integrated quantum information processing circuits, including photon sources, qubit manipulation, and integrated single-photon detectors. Here, we present the key aspects of preparing and testing a silicon photonic quantum chip with an integrated photon source and two-photon interferometer. The most important aspect of an integrated quantum circuit is minimizing loss so that all of the generated photons are detected with the highest possible fidelity. Here, we describe how to perform low-loss edge coupling by using an ultra-high numerical aperture fiber to closely match the mode of the silicon waveguides. By using an optimized fusion splicing recipe, the UHNA fiber is seamlessly interfaced with a standard single-mode fiber. This low-loss coupling allows the measurement of high-fidelity photon production in an integrated silicon ring resonator and the subsequent two-photon interference of the produced photons in a closely integrated Mach-Zehnder interferometer. This paper describes the essential procedures for the preparation and characterization of high-performance and scalable silicon quantum photonic circuits.

Silicon photonic chips have the potential to realize complex integrated quantum systems. Presented here is a method for preparing and testing a silicon photonic chip for quantum measurements.

シリコンリング共振器光子源における量子干渉の測定

Silicon photonic chips have the potential to realize complex integrated quantum information processing circuits, including photon sources, qubit ...

High-speed Continuous-wave Stimulated Brillouin Scattering Spectrometer for Material Analysis

Recent years have witnessed a significant increase in the use of spontaneous Brillouin spectrometers for non-contact analysis of soft matter, such as aqueous solutions and biomaterials, with fast acquisition times. Here, we discuss the assembly and operation of a Brillouin spectrometer that uses stimulated Brillouin scattering (SBS) to measure stimulated Brillouin gain (SBG) spectra of water and lipid emulsion-based tissue-like samples in transmission mode with &lt;10 MHz spectral-resolution and &lt;35 MHz Brillouin-shift measurement precision at &lt;100 ms. The spectrometer consists of two nearly counter-propagating continuous-wave (CW) narrow-linewidth lasers at 780 nm whose frequency detuning is scanned through the material Brillouin shift. By using an ultra-narrowband hot rubidium-85 vapor notch filter and a phase-sensitive detector, the signal-to-noise-ratio of the SBG signal is significantly enhanced compared to that obtained with existing CW-SBS spectrometers. This improvement enables measurement of SBG spectra with up to 100-fold faster acquisition times, thereby facilitating high spectral-resolution and high-precision Brillouin analysis of soft materials at high speed.

We describe the construction of a rapid continuous-wave-stimulated-Brillouin-scattering (CW-SBS) spectrometer. The spectrometer employs single-frequency diode-lasers and an atomic vapor notch-filter to acquire transmission spectra of turbid/non-turbid samples with high spectral-resolution at speeds up to 100-fold faster than those of existing CW-SBS spectrometers. This improvement enables high-speed Brillouin material analysis.

材料の分析のための高速連続誘導ブリルアン散乱分光器

Recent years have witnessed a significant increase in the use of spontaneous Brillouin spectrometers for non-contact analysis of soft matter, such as ...

Generation and Coherent Control of Pulsed Quantum Frequency Combs

We present a method for the generation and coherent manipulation of pulsed quantum frequency combs. Until now, methods of preparing high-dimensional states on-chip in a practical way have remained elusive due to the increasing complexity of the quantum circuitry needed to prepare and process such states. Here, we outline how high-dimensional, frequency-bin entangled, two-photon states can be generated at a stable, high generation rate by using a nested-cavity, actively mode-locked excitation of a nonlinear micro-cavity. This technique is used to produce pulsed quantum frequency combs. Moreover, we present how the quantum states can be coherently manipulated using standard telecommunications components such as programmable filters and electro-optic modulators. In particular, we show in detail how to accomplish state characterization measurements such as density matrix reconstruction, coincidence detection, and single photon spectrum determination. The presented methods form an accessible, reconfigurable, and scalable foundation for complex high-dimensional state preparation and manipulation protocols in the frequency domain.

A protocol is presented for the practical generation and coherent manipulation of high-dimensional frequency-bin entangled photon states using integrated micro-cavities and standard telecommunications components, respectively.

世代とパルスの量子周波数コムのコヒーレント制御

We present a method for the generation and coherent manipulation of pulsed quantum frequency combs. Until now, methods of preparing high-dimensional ...

Highly Resolved Intravital Striped-illumination Microscopy of Germinal Centers

Monitoring cellular communication by intravital deep-tissue multi-photon microscopy is the key for understanding the fate of immune cells within thick tissue samples and organs in health and disease. By controlling the scanning pattern in multi-photon microscopy and applying appropriate numerical algorithms, we developed a striped-illumination approach, which enabled us to achieve 3-fold better axial resolution and improved signal-to-noise ratio, i.e. contrast, in more than 100 &#181;m tissue depth within highly scattering tissue of lymphoid organs as compared to standard multi-photon microscopy. The acquisition speed as well as photobleaching and photodamage effects were similar to standard photo-multiplier-based technique, whereas the imaging depth was slightly lower due to the use of field detectors. By using the striped-illumination approach, we are able to observe the dynamics of immune complex deposits on secondary follicular dendritic cells &#8211; on the level of a few protein molecules in germinal centers.

High-resolution intravital imaging with enhanced contrast up to 120 &#181;m depth in lymph nodes of adult mice is achieved by spatially modulating the excitation pattern of a multi-focal two-photon microscope. In 100 &#181;m depth we measured resolutions of 487 nm (lateral) and 551 nm (axial), thus circumventing scattering and diffraction limits.

胚中心の高解像度生体内ストライプ照明顕微鏡

Monitoring cellular communication by intravital deep-tissue multi-photon microscopy is the key for understanding the fate of immune cells within thick ...

免疫・感染学

Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator

The aim of this article is to visually demonstrate the utilization of an interferometric method for encoding complex fields associated with coherent laser radiation. The method is based on the coherent sum of two uniform waves, previously encoded into a phase-only spatial light modulator (SLM) by spatial multiplexing of their phases. Here, the interference process is carried out by spatial filtering of light frequencies at the Fourier plane of certain imaging system. The correct implementation of this method allows arbitrary phase and amplitude information to be retrieved at the output of the optical system.
It is an on-axis, rather than off-axis encoding technique, with a direct processing algorithm (not an iterative loop), and free from coherent noise (speckle). The complex field can be exactly retrieved at the output of the optical system, except for some loss of resolution due to the frequency filtering process. The main limitation of the method might come from the inability to operate at frequency rates higher than the refresh rate of the SLM. Applications include, but are not limited to, linear and non-linear microscopy, beam shaping, or laser micro-processing of material surfaces.

We show how to encode the complex field of laser beams by using a single phase element. A common-path interferometer is employed to mix the phase information displayed into a phase-only spatial light modulator to finally retrieve the desired complex field pattern at the output of an optical imaging system.

位相空間光変調を用いた振幅とレーザー光の位相を形成

The aim of this article is to visually demonstrate the utilization of an interferometric method for encoding complex fields associated with coherent laser ...

X-ray Beam Induced Current Measurements for Multi-Modal X-ray Microscopy of Solar Cells

X-ray beam induced current (XBIC) measurements allow mapping of&#160;the nanoscale performance of electronic devices such as solar cells. Ideally, XBIC is employed simultaneously with other techniques within a multi-modal X-ray microscopy approach. An example is given herein combining XBIC with X-ray fluorescence to enable point-by-point correlations of the electrical performance with chemical composition. For the highest signal-to-noise ratio in XBIC measurements, lock-in amplification plays a crucial role. By this approach, the X-ray beam is modulated by an optical chopper upstream of the sample. The modulated X-ray beam induced electrical signal is amplified and demodulated to the chopper frequency using a lock-in amplifier. By optimizing low-pass filter settings, modulation frequency, and amplification amplitudes, noise can efficiently be suppressed for the extraction of a clear XBIC signal. A similar setup can be used to measure the X-ray beam induced voltage (XBIV). Beyond standard XBIC/XBIV measurements, XBIC can be measured with bias light or bias voltage applied such that outdoor working conditions of solar cells can be reproduced during in-situ and operando measurements. Ultimately, the multi-modal and multi-dimensional evaluation of electronic devices at the nanoscale enables new insights into the complex dependencies between composition, structure, and performance, which is an important step towards solving the materials&#39; paradigm.

A setup for X-ray beam induced current measurements at synchrotron beamlines is described. It unveils the nanoscale performance of solar cells and extends the suite of techniques for multi-modal X-ray microscopy. From wiring to signal-to-noise optimization, it is shown how to perform state-of-the-art XBIC measurements at a hard X-ray microprobe.

太陽電池のマルチモーダルX線顕微鏡検査におけるX線ビーム誘導電流測定

X-ray beam induced current (XBIC) measurements allow mapping of&#160;the nanoscale performance of electronic devices such as solar cells. Ideally, XBIC is ...

Spectral and Angle-Resolved Magneto-Optical Characterization of Photonic Nanostructures

Photonic crystals are periodic nanostructures that can support a variety of confined electromagnetic modes. Such confined modes are usually accompanied by local enhancement of electric field intensity that strengthens light-matter interactions, enabling applications such as surface-enhanced Raman scattering (SERS) and surface plasmon enhanced sensing. In the presence of magneto-optically active materials, the local field enhancement gives rise to anomalous magneto-optical activity. Typically, the confined modes of a given photonic crystal depend strongly on the wavelength and incidence angle of the incident electromagnetic radiation. Thus, spectral and angular-resolved measurements are needed to fully identify them as well as to establish their relationship with the magneto-optical activity of the crystal. In this article, we describe how to use a Fourier-plane (back focal plane) microscope to characterize magneto-optically active samples. As a model system, here we use a plasmonic grating built out of magneto-optically active Au/Co/Au multilayer. In the experiments, we apply a magnetic field on the grating in situ and measure its reciprocal space response, obtaining the magneto-optical response of the grating over a range of wavelengths and incident angles. This information enables us to build a complete map of the plasmonic band structure of the grating and the angle and wavelength dependent magneto-optical activity. These two images allow us to pinpoint the effect that the plasmon resonances have on the magneto-optical response of the grating. The relatively small magnitude of magneto-optical effects requires a careful treatment of the acquired optical signals. To this end, an image processing protocol for obtaining magneto-optical response from the acquired raw data is laid out.

Photonic band structure enables understanding how confined electromagnetic modes propagate within a photonic crystal. In photonic crystals that incorporate magnetic elements, such confined and resonant optical modes are accompanied by enhanced and modified magneto-optical activity. We describe a measurement procedure to extract the magneto-optical band structure by Fourier space microscopy.

フォトニックナノ構造のスペクトルと角度分解磁気光学特性

Photonic crystals are periodic nanostructures that can support a variety of confined electromagnetic modes. Such confined modes are usually accompanied by ...

Characterization of SiN Integrated Optical Phased Arrays on a Wafer-Scale Test Station

Optical phased arrays (OPAs) can produce low-divergence laser beams and can be used to control the emission angle electronically without the need for moving mechanical parts. This technology is particularly useful for beam steering applications. Here, we focus on OPAs integrated into SiN photonic circuits for a wavelength in the near infrared. A characterization method of such circuits is presented, which allows the output beam of integrated OPAs to be shaped and steered. Furthermore, using a wafer-scale characterization setup, several devices can easily be tested across multiple dies on a wafer. In this way, fabrication variations can be studied, and high-performance devices identified. Typical images of OPA beams are shown, including beams emitted from OPAs with and without a uniform waveguide length, and with varying numbers of channels. In addition, the evolution of output beams during the phase optimization process and beam steering in two dimensions is presented. Finally, a study of the variation in the beam divergence of identical devices is performed with respect to their position on the wafer.

Here, we describe the operation of a SiN integrated photonic circuit containing optical phased arrays. The circuits are used to emit low divergence laser beams in the near infrared and steer them in two dimensions.

ウェーハスケール試験場におけるSiN統合光フェーズドアレイの特性評価

Optical phased arrays (OPAs) can produce low-divergence laser beams and can be used to control the emission angle electronically without the need for ...