The financial support by DFG (German research foundation, project CZ 55/30-1) for parts of this work is gratefully acknowledged.

1.実験のセットアップを組み立て<ol><li> 近位側の準備 <ol><li>配置し、平行光ビームを提供するレーザーを修正 - またはファイバの出射端面での視準光学系とファイバ結合レーザーを使用しています。 </li><li>参照物体ビームにレーザビームを分割する偏光ビームスプリッタ（PBS）を置きます。 （先端側）の参照光と物体光のパワーがほぼ同じになるまでマウントその回転にHWPを回転させることにより、半波長板（HWP）の方向に回します。リファレンスと物体光の両方にスクリーンを置くことによって、これを確認してください。参照ビームの偏光は、偏光に敏感な空間光変調器（SLM）に収まるようにPBSの向きを選択します。 </li><li> 2つのビームに基準ビームを分割する基準ビームにビームスプリッタ（BS）を置きます。 BS1からのこれら二つのビームはそれぞれ、OM1とOM2を渡すことができるような光変調器（OM）を配置します。&lt;/李&gt; <li>二つのミラーを採用したBS2でOM1とOM2を通過する二つのビームを結合します。両方のビームが空間的に分離されるように、ビームスプリッタとミラーを調整します。 </li><li>慎重に両ビームの入射方向が最初でBS3とBS4を無視して、SLMの画素面に垂直であることを確認するために、BS5を揃えます。最初は、何もSLM上に表示されていない、 すなわち 、それは（ステップ2を通じて）、キャリブレーションが終了するまで、ミラーのように作用します。 </li><li>位置と二つのレンズ（L）との間の距離相補型金属酸化膜半導体（CMOS）カメラでSLM面の鮮明な画像を得るためにケプラー望遠鏡を構成し調整します。 L1とL2の正しい方向を見て、収差を最小化するために（平坦な側面が互いに対向しています）。 </li></ol></li><li> 遠位側の準備 <ol><li> 2つのビームに物体光を分割し、2ミラーを採用しBS8でそれらを組み合わせることBS7を使用してください。ここでも、ビームスプリッタとマイルを調整両方のビームが空間的に分離されるようにrrors。 </li><li>顕微鏡対物レンズ（OBJ）にそれらを目指してBS9を使用して両方のビームを偏向。マルチモードファイバ（MMF）の先端にOBJ2焦点を当てます。 L3および電荷結合素子（CCD）カメラを採用したMMFからの後方反射を観察することによりピントを確認してください。 </li></ol></li><li> 接続する近位および遠位側 <ol><li> MMF採用OBJ1を出た物体光からの光を平行。 </li><li>最初は直線偏光子（LP）を無視し、BS6を使用してオブジェクトビームを分割します。 BS3とBS4の両方で参照光ミラーを採用して、両方の物体光を兼ね備えています。ビームスプリッタとミラーを調整するように小さな角度（1°未満）と交差するSLMでの基準と物体光の重なりの各ペア、。 </li><li>リファレンスのパワーと物体光は、ステップ1.1.2によると、HWPの向きを回転させることによりほぼ等しいことを確認してください。 </li><li>干渉pをチェックCMOSカメラでattern（オフアクシスホログラム）、それに応じて交差角度を調整します。干渉縞の間隔はおおよそのCMOSカメラの2つの画素の大きさに等しくなるまで、角度を大きくします。 </li><li>カメラ画像は異なる縞を示すように、CMOSカメラ画像における干渉パターンの最大のコントラストを得るためにオブジェクトと参照光の偏光に一致するようにLPの向きを調整します。 </li></ol></li></ol> 2.システムのキャリブレーション<ol><li> SLMとCMOSとの画素の関係をキャリブレーション <ol><li>参照光の一方のみを用いて全SLMを照射し、他の参照をブロックし、ビームをオブジェクト。 </li><li> CMOSカメラとSLMの画像をキャプチャします。 </li><li> 例えば PCでグラフィックソフトウェアとマウスカーソルを使用して、CMOSのカメラ画像におけるSLMの左上隅の座標を取得します。これらのピクセル座標は原点として使用しますSLMに関する。 </li><li>すべてのビームブロックを削除します。 </li></ol></li><li> 信号経路のキャリブレーション <ol><li>参照光2と物体ビーム2の両方をブロックします。 </li><li> CMOSカメラとホログラムの画像をキャプチャします。角スペクトル法19を使用して記録されたホログラムの位相を評価します。ビーム1の対応する領域での位相反転を計算します。 </li><li>ビームフォーマのブロックを削除し、現在参照ビーム1と物体光1の両方をブロックします。 </li><li> CMOSカメラとホログラムの画像をキャプチャします。再び角スペクトル法を用いて記録されたホログラムの位相を測定します。ビーム2の対応する領域で反転位相を計算します。 </li><li>すべてのビームブロックを削除します。 </li></ol></li></ol> 3.信号を送信します<ol><li>物体光をブロックします。 </li><li>一緒ビーム1,2の対応する領域で計算反転位相画像をステッチして表示SLM上の画像全体は、典型的には、コンピュータグラフィックスポートを使用します。 </li><li> OM1とOM2を活性化することによって、入力信号1及び2の変調を開始します。 </li><li> CCDカメラの出力信号1と2を観察します。 </li></ol>

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The authors have nothing to disclose.

実験（プロトコルにおけるステップ1）の組立は、互いに対する光学部品の徹底的な位置合わせを必要とします。最も重要な側面は、高PBRを確保するためにSLM上に参照光の矩形発生です。 二つ以上の送信信号の設定を高めるために、追加のビームスプリッタを使用することができます。別の方法として、光ファイバベースの実装は、よりコンパクトで、システムはバイオ?...

マルチモードファイバ（MMF）を介して複数の光信号の伝送は、通信技術1及びバイオフォトニクス2に明らかです。通信技術において、空間分割多重（SDM）は、複数のシングルモードファイバと比較して、限られた空間の高い利用の恩恵を受け、将来のデータ転送アプリケーション用の光ファイバの伝送容量を高めるために実行可能な解決策であると考えられています3。バイオフォトニクスでは、生物学的サンプルは、MMF内視鏡4を透過する光によって操作されています。例えば、MMFの内視鏡を使用して、個々のニューロンの独立した光制御は、脳5におけるニューロンネットワークを研究するために、光遺伝学のために重要です。しかし、MMF入力ファセットに投影される光は、outpuへの伝播中に歪みによるモードの混合分散の対象となりますMMFのトンファセット。その結果、光の伝搬は、信号伝送が困難な作るれ、変更されます。 波面整形方法6は 、 図7に示すように 、空間光変調器（SLM）を使用して、散乱媒体に適用し、光による伝播8時の散乱による歪みの補償を可能にしています。光フィードバック9を使用して出力を最適化する反復アプローチがあります。これらのアプローチは、変調器要素の多くに対応するために多数の反復の必要性と高い自由度のかかるかなりの時間です。別のアプローチは、完全にその送信行列10によって記述MMF内の歪みを決定することです。送信されるモードの数が多い場合、これは、同様に時間がかかるであろう。対照的に、デジタル光位相共役（DOPC）があると考えられています迅速かつ有利ここで、ほんの数焦点がMMFの出力面で生成されなければならないからです。位相共役アプローチは、生体組織12、13、14を介して集束またはイメージングのために実証されています。 これまで、DOPCは、単一の時間信号のみ15、16のために使用し、そしてMMF 17を通る光の透過のために適用しました。複数の独立した信号のDOPCのアプローチがなされていません。我々は、単相のみのSLM 18を用いて 、各信号のために整形する個々の波面を使用して複数の光信号の独立した伝送を提供する強化されたDOPC方法を開発しました。この目的のために、SLMは各信号に対して1つを送信する、領域に分割されます。提案された実験は、 図1に示されていますキャリブレーションは、実際の送信前）に行われる場合、）（b）に発生します。 <img alt="図1" src="/files/ftp_upload/55407/55407fig1.jpg" /> 図1：実験セットアップ。 BS =ビームスプリッタ、CCD =電荷結合素子、OM =光変調器、CMOS =相補型金属酸化膜半導体、HWP =半波長板、L =レンズ、LP =直線偏光子、MMF =マルチモードファイバ、OBJ =顕微鏡対物レンズ、 PBSは=偏光ビームスプリッタ、SLM =空間光変調器（位相のみ） - （a）のキャリブレーションおよび（b）の伝送にのみ関連ビームが描かれている<a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55407/55407fig1large.jpg" target="_blank">。この図の拡大版をご覧になるにはこちらをクリックしてください。</a>

<table><tbody><tr><td>spatial light modulator</td><td>Holoeye</td><td>PLUTO-VIS-016</td><td></td></tr><tr><td>CMOS camera</td><td>Mikrotron</td><td>MC4082</td><td></td></tr><tr><td>diode-pumped solid state laser</td><td>Laser Quantum</td><td>torus 532</td><td></td></tr><tr><td>CCD camera</td><td>IDS</td><td>U3-3482LE-M CMOS</td><td>camera; suitable as well</td></tr><tr><td>lens 1</td><td>Qioptiq</td><td>G063204000</td><td></td></tr><tr><td>lens 2</td><td>Qioptiq</td><td>G063203000</td><td></td></tr><tr><td>lens 3</td><td>Thorlabs</td><td>AC508-180-A-ML</td><td></td></tr><tr><td>multimode fiber</td><td>Thorlabs</td><td>M14L02</td><td></td></tr><tr><td>beam splitters</td><td>Thorlabs</td><td>BS013</td><td>9x</td></tr><tr><td>polarizing beam splitters</td><td>Thorlabs</td><td>PBS251</td><td></td></tr><tr><td>mirrors</td><td>Thorlabs</td><td>PF10-03-P01</td><td>5x</td></tr><tr><td>microscope objectives</td><td>Thorlabs</td><td>RMS20X</td><td>2x</td></tr><tr><td>half wave plates</td><td>Thorlabs</td><td>WPH10M-532</td><td>2x</td></tr><tr><td>linear polarizer</td><td>Thorlabs</td><td>LPVISB050-MP2</td><td></td></tr><tr><td>optical modulators</td><td>Thorlabs</td><td>MC2000B-EC</td><td>2x</td></tr><tr><td>linear and rotation stage for CMOS camera</td><td>Thorlabs</td><td>XYR1/M</td><td></td></tr><tr><td>fiber connector</td><td>Thorlabs</td><td>S120-SMA</td><td>2x</td></tr><tr><td>reducing ring for microscope objectives</td><td>Qioptiq</td><td>G061621000</td><td>2x</td></tr><tr><td>xy adjustment for objective adapters</td><td>Qioptiq</td><td>G061025000</td><td>2x</td></tr><tr><td>z translation mount for fiber adapter</td><td>Thorlabs</td><td>SM1Z</td><td>2x</td></tr><tr><td>rods for fiber alignment to objectives</td><td>Qioptiq</td><td>G061210000</td><td>8x</td></tr><tr><td>mounts for lenses 1 and 2 plus two phantom mounts</td><td>Qioptiq</td><td>G061047000</td><td>4x</td></tr><tr><td>rail carriers for objective and lens mounts</td><td>Qioptiq</td><td>G061372000</td><td>6x</td></tr><tr><td>rail for rail carriers</td><td>Qioptiq</td><td>G061359000</td><td>2x</td></tr><tr><td>adapter for CCD camera to 1 post</td><td></td><td></td><td>in-house</td></tr><tr><td>adapter for laser to 4 posts</td><td></td><td></td><td>in-house</td></tr><tr><td>mount for lens 3</td><td>Thorlabs</td><td>LMR2/M</td><td></td></tr><tr><td>mounts for half wave plates</td><td>Thorlabs</td><td>RSP1D/M</td><td>2</td></tr><tr><td>mounts for mirrors</td><td>Thorlabs</td><td>KM100</td><td>5x</td></tr><tr><td>mount for linear polarizer</td><td>Thorlabs</td><td>RSP05/M</td><td></td></tr><tr><td>mounts for beam splitters and SLM</td><td>Thorlabs</td><td>KM100PM/M</td><td>11x</td></tr><tr><td>clamping arms for beam splitters and SLM</td><td>Thorlabs</td><td>PM4/M</td><td>11x</td></tr><tr><td>posts for mounts, rail carriers and adapters</td><td>Thorlabs</td><td>TR75/M</td><td>29x</td></tr><tr><td>holders for posts</td><td>Thorlabs</td><td>PH50/M</td><td>29x</td></tr><tr><td>pedestals for holders</td><td>Thorlabs</td><td>BE1/M</td><td>29x</td></tr><tr><td>clamping forks for pedestals</td><td>Thorlabs</td><td>CF125</td><td>29x</td></tr></tbody></table>

transmission of multiple signals through an optical fiber using wavefront shaping

マルチモード光ファイバを介して複数の独立した光信号の伝送は、ファイバ内伝搬中の光の歪みを補償するために、波面整形を用いて達成されます。私たちの方法論は、光の波面を個別変調器の異なる領域で変調された単一の空間光変調器、光信号ごとに一つの領域を使用するデジタル光位相共役に基づいています。デジタル光位相共役アプローチは、繊維の波伝播挙動の完全な決意が行われる（例えば）他の波面成形アプローチよりも速くなると考えられます。それが唯一の光信号ごとに1キャリブレーションを必要とするのでこれとは対照的に、提示されたアプローチは、時間効率的です。提案手法は、通信工学における空間分割多重化のための潜在的に適切です。さらに応用分野は、特にOで、バイオフォトニクスにおける内視鏡の光配信されています生体組織内の単一の細胞が選択的に高い空間分解能と時間分解能で照明されなければならないptogenetics、。

<html>長さ2mファイバの先端側の典型的な出力信号は、 図2に示されています。所望の焦点スポット（ピーク）は原則としてDOPCの不完全性に起因する望ましくないスペックルパターン（背景）、を伴っていることに注意してください。対応するピーク対バックグラウンド比（PBR）が53に達する（単に信号1が &#39;on&#39;である）、36はそれぞれ、ここで（両方の...

Watch this Scientific Journal Video about Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping at JoVE.com

Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping

We demonstrate the transmission of multiple independent signals through a multimode fiber using wavefront shaping employing a single spatial light modulator. By modulating the wavefront for each signal individually, spatially separated foci are transmitted. Potential applications are multiplexed data transfer in communications engineering and endoscopic light delivery in biophotonics.

ウェーブフロントシェイピングを用いた光ファイバを介して複数の信号の伝送

The transmission of multiple independent optical signals through a multimode fiber is accomplished using wavefront shaping in order to compensate for the ...

transmission-multiple-signals-through-an-optical-fiber-using

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9.8K ビュー.  TU Dresden. We demonstrate the transmission of multiple independent signals through a multimode fiber using wavefront shaping employing a single spatial light modulator. By modulating the wavefront for each signal individually, spatially separated foci are transmitted. Potential applications are multiplexed data transfer in communications engineering and endoscopic light delivery in biophotonics.

ビデオ: Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping

Microwave Photonics Systems Based on Whispering-gallery-mode Resonators

Microwave photonics systems rely fundamentally on the interaction between microwave and optical signals. These systems are extremely promising for various areas of technology and applied science, such as aerospace and communication engineering, sensing, metrology, nonlinear photonics, and quantum optics. In this article, we present the principal techniques used in our lab to build microwave photonics systems based on ultra-high Q whispering gallery mode resonators. First detailed in this article is the protocol for resonator polishing, which is based on a grind-and-polish technique close to the ones used to polish optical components such as lenses or telescope mirrors. Then, a white light interferometric profilometer measures surface roughness, which is a key parameter to characterize the quality of the polishing. In order to launch light in the resonator, a tapered silica fiber with diameter in the micrometer range is used. To reach such small diameters, we adopt the "flame-brushing" technique, using simultaneously computer-controlled motors to pull the fiber apart, and a blowtorch to heat the fiber area to be tapered. The resonator and the tapered fiber are later approached to one another to visualize the resonance signal of the whispering gallery modes using a wavelength-scanning laser. By increasing the optical power in the resonator, nonlinear phenomena are triggered until the formation of a Kerr optical frequency comb is observed with a spectrum made of equidistant spectral lines. These Kerr comb spectra have exceptional characteristics that are suitable for several applications in science and technology. We consider the application related to ultra-stable microwave frequency synthesis and demonstrate the generation of a Kerr comb with GHz intermodal frequency.

The customized techniques developed in our lab to build microwave photonics systems based on ultra-high Q whispering gallery mode resonators are presented. The protocols to obtain and characterize these resonators are detailed, and an explanation of some of their applications in microwave photonics is given.

ウィスパリングギャラリーモード共振器に基づいたマイクロ波フォトニクスシステム

Microwave photonics systems rely fundamentally on the interaction between microwave and optical signals. These systems are extremely promising for various ...

工学

Quasi-light Storage for Optical Data Packets

Today's telecommunication is based on optical packets which transmit the information in optical fiber networks around the world. Currently, the processing of the signals is done in the electrical domain. Direct storage in the optical domain would avoid the transfer of the packets to the electrical and back to the optical domain in every network node and, therefore, increase the speed and possibly reduce the energy consumption of telecommunications. However, light consists of photons which propagate with the speed of light in vacuum. Thus, the storage of light is a big challenge. There exist some methods to slow down the speed of the light, or to store it in excitations of a medium. However, these methods cannot be used for the storage of optical data packets used in telecommunications networks. Here we show how the time-frequency-coherence, which holds for every signal and therefore for optical packets as well, can be exploited to build an optical memory. We will review the background and show in detail and through examples, how a frequency comb can be used for the copying of an optical packet which enters the memory. One of these time domain copies is then extracted from the memory by a time domain switch. We will show this method for intensity as well as for phase modulated signals.

The article describes a procedure to store optical data packets with an arbitrary modulation, wavelength, and data rate. These packets are the basis of modern telecommunications.

光データパケットのための準光ストレージ

Today's telecommunication is based on optical packets which transmit the information in optical fiber networks around the world. Currently, the processing ...

Fabrication and Characterization of Disordered Polymer Optical Fibers for Transverse Anderson Localization of Light

We develop and characterize a disordered polymer optical fiber that uses transverse Anderson localization as a novel waveguiding mechanism. The developed polymer optical fiber is composed of 80,000 strands of poly (methyl methacrylate) (PMMA) and polystyrene (PS) that are randomly mixed and drawn into a square cross section optical fiber with a side width of 250 &mu;m. Initially, each strand is 200 &mu;m in diameter and 8-inches long. During the mixing process of the original fiber strands, the fibers cross over each other; however, a large draw ratio guarantees that the refractive index profile is invariant along the length of the fiber for several tens of centimeters. The large refractive index difference of 0.1 between the disordered sites results in a small localized beam radius that is comparable to the beam radius of conventional optical fibers. The input light is launched from a standard single mode optical fiber using the butt-coupling method and the near-field output beam from the disordered fiber is imaged using a 40X objective and a CCD camera. The output beam diameter agrees well with the expected results from the numerical simulations. The disordered optical fiber presented in this work is the first device-level implementation of 2D Anderson localization, and can potentially be used for image transport and short-haul optical communication systems.

We develop and characterize a disordered polymer optical fiber that uses transverse Anderson localization as a novel waveguiding mechanism. This microstructured fiber can transport a small localized beam with a radius that is comparable to the beam radius of conventional optical fibers.

ライトの横アンダーソン局在のために無秩序ポリマー光ファイバの作製と評価

We develop and characterize a disordered polymer optical fiber that uses transverse Anderson localization as a novel waveguiding mechanism. The developed ...

Writing Bragg Gratings in Multicore Fibers

Fiber Bragg gratings in multicore fibers can be used as compact and robust filters in astronomical and other research and commercial applications. Strong suppression at a single wavelength requires that all cores have matching transmission profiles. These gratings cannot be inscribed using the same method as for single-core fibers because the curved surface of the cladding acts as a lens, focusing the incoming UV laser beam and causing variations in exposure between cores. Therefore we use an additional optical element to ensure that the beam shape does not change while passing through the cross-section of the multicore fiber. This consists of a glass capillary tube which has been polished flat on one side, which is then placed over the section of the fiber to be inscribed. The laser beam enters the fiber through the flat surface of the capillary tube and hence maintains its original dimensions. This paper demonstrates the improvements in core-to-core uniformity for a 7-core fiber using this method. The technique can be generalized to larger multicore fibers.

We describe a technique for inscribing identical fiber Bragg gratings into each core of a multicore fiber. This is achieved by introducing an additional surface into the optical path to mitigate lensing by the curved surface of the fiber cladding.

マルチコアファイバーブラッググレーティングを書きます

Fiber Bragg gratings in multicore fibers can be used as compact and robust filters in astronomical and other research and commercial applications. Strong ...

High-Throughput Total Internal Reflection Fluorescence and Direct Stochastic Optical Reconstruction Microscopy Using a Photonic Chip

Total internal reflection fluorescence (TIRF) is commonly used in single molecule localization based super-resolution microscopy as it gives enhanced contrast due to optical sectioning. The conventional approach is to use high numerical aperture microscope TIRF objectives for both excitation and collection, severely limiting the field of view and throughput. We present a novel approach to generating TIRF excitation for imaging with optical waveguides, called chip-based nanoscopy. The aim of this protocol is to demonstrate how chip-based imaging is performed in an already built setup. The main advantage of chip-based nanoscopy is that the excitation and collection pathways are decoupled. Imaging can then be done with a low magnification lens, resulting in large field of view TIRF images, at the price of a small reduction in resolution. Liver sinusoidal endothelial cells (LSECs) were imaged using direct stochastic optical reconstruction microscopy (dSTORM), showing a resolution comparable to traditional super-resolution microscopes. In addition, we demonstrate the high-throughput capabilities by imaging a 500 &#181;m x 500 &#181;m region with a low magnification lens, providing a resolution of 76 nm. Through its compact character, chip-based imaging can be retrofitted into most common microscopes and can be combined with other on-chip optical techniques, such as on-chip sensing, spectroscopy, optical trapping, etc. The technique is thus ideally suited for high throughput 2D super-resolution imaging, but also offers great opportunities for multi-modal analysis.

Chip-based super-resolution optical microscopy is a novel approach to fluorescence microscopy and offers advantages in cost effectiveness and throughput. Here, the protocols for chip preparation and imaging are shown for TIRF microscopy and localization-based super-resolution microscopy.

フォトニックチップを用いたハイスループット全内部反射蛍光と直接確率光学再構成顕微鏡

Total internal reflection fluorescence (TIRF) is commonly used in single molecule localization based super-resolution microscopy as it gives enhanced ...

生化学

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 ...

Low-cost Custom Fabrication and Mode-locked Operation of an All-normal-dispersion Femtosecond Fiber Laser for Multiphoton Microscopy

A protocol is presented to build a custom low-cost yet high-performance femtosecond (fs) fiber laser. This all-normal-dispersion (ANDi) ytterbium-doped fiber laser is built completely using commercially available parts, including $8,000 in fiber optic and pump laser components, plus $4,800 in standard optical components and extra-cavity accessories. Researchers new to fiber optic device fabrication may also consider investing in basic fiber splicing and laser pulse characterization equipment (~$63,000). Important for optimal laser operation, methods to verify true versus apparent (partial or noise-like) mode-locked performance are presented. This system achieves 70 fs pulse duration with a center wavelength of approximately 1,070 nm and a pulse repetition rate of 31 MHz. This fiber laser exhibits the peak performance that may be obtained for an easily assembled fiber laser system, which makes this design ideal for research laboratories aiming to develop compact and portable fs laser technologies that enable new implementations of clinical multiphoton microscopy and fs surgery.

A method is presented to build a custom low-cost, mode-locked femtosecond fiber laser for potential applications in multiphoton microscopy, endoscopy, and photomedicine. This laser is built using commercially available parts and basic splicing techniques.

多光子顕微鏡用全常常分散フェムト秒ファイバーレーザーの低コストカスタム製造とモードロック動作

A protocol is presented to build a custom low-cost yet high-performance femtosecond (fs) fiber laser. This all-normal-dispersion (ANDi) ytterbium-doped ...

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 ...

Multicolor Fluorescence Detection for Droplet Microfluidics Using Optical Fibers

Fluorescence assays are the most common readouts used in droplet microfluidics due to their bright signals and fast time response. Applications such as multiplex assays, enzyme evolution, and molecular biology enhanced cell sorting require the detection of two or more colors of fluorescence. Standard multicolor detection systems that couple free space lasers to epifluorescence microscopes are bulky, expensive, and difficult to maintain. In this paper, we describe a scheme to perform multicolor detection by exciting discrete regions of a microfluidic channel with lasers coupled to optical fibers. Emitted light is collected by an optical fiber coupled to a single photodetector. Because the excitation occurs at different spatial locations, the identity of emitted light can be encoded as a temporal shift, eliminating the need for more complicated light filtering schemes. The system has been used to detect droplet populations containing four unique combinations of dyes and to detect sub-nanomolar concentrations of fluorescein.

Multicolor fluorescence detection in droplet microfluidics typically involves bulky and complex epifluorescence microscope-based detection systems. Here we describe a compact and modular multicolor detection scheme that utilizes an array of optical fibers to temporally encode multicolor data collected by a single photodetector.

光ファイバを用いて、液滴マイクロフルイディクスのための多色蛍光検出

Fluorescence assays are the most common readouts used in droplet microfluidics due to their bright signals and fast time response. Applications such as ...

生物工学

Optimizing Brillouin Optical Time-Domain Analyzers Based on Gain Spectrum Engineering

Demonstrated is a unique method for sensing performance enhancement in Brillouin optical time-domain analyzers (BOTDA). A Brillouin gain spectrum (BGS) is superimposed with two symmetric Brillouin loss spectra (BLS). This leads to a complex engineered spectrum shape that is more resistant to the sensing system noise. Instead of only one pump and probe interaction as in the conventional BOTDA setup, three optical probe waves are exploited, with one probe located in the BGS and the other two symmetrically in the BLS. Due to the resistance and insensitivity of the engineered spectrum shape to the noise, the sensing performance is enhanced by 60% and the measurand resolution is doubled.

<meta charset="utf8"></head><body>ゲインスペクトル工学に基づくブリルアン光時間領域アナライザの最適化

A protocol for Brillouin optical time-domain analyzers based on gain spectrum engineering is presented. Enhancements in the sensing performance, including sensing range and measurand resolution are achieved and the excess Brillouin intensity noise is studied. The protocol introduces a new way to enhance distributed Brillouin sensing performance.

ゲインスペクトル工学に基づくブリルアン光時間領域アナライザの最適化

Demonstrated is a unique method for sensing performance enhancement in Brillouin optical time-domain analyzers (BOTDA). A Brillouin gain spectrum (BGS) is ...