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

1. Montage de l&#39;installation expérimentale <ol><li> Préparation de la partie proximale <ol><li> Placer et fixer le laser fournissant un faisceau de lumière collimatée - ou utiliser un laser à fibre couplée à une optique de collimation à la facette de sortie de la fibre. </li><li> Mettez le diviseur de faisceau polarisant (PBS) pour diviser le faisceau laser en référence et faisceau objet. Tourner l&#39;orientation des lames d&#39;onde demi (PLR) en faisant tourner le HWP dans sa rotation monter jusqu&#39;à ce que la puissance du faisceau de référence et faisceau objet (sur le côté distal) est à peu près la même chose. Vérifiez cela en mettant un écran à la fois référence et faisceau objet. Choisir l&#39;orientation du PBS de telle sorte que la polarisation du faisceau de référence correspond à la modulation spatiale de lumière sensible à la polarisation (SLM). </li><li> Placer un séparateur de faisceau (BS) dans le faisceau de référence pour diviser le faisceau de référence en deux faisceaux. Placer les modulateurs optiques (OM) de sorte que ces deux faisceaux issus BS1 peuvent passer OM1 et OM2, respectivement. &lt;/ Li&gt; <li> Combinez les deux faisceaux passant OM1 et OM2 à BS2 employant deux miroirs. Réglez les séparateurs de faisceau et des miroirs de telle sorte que les deux faisceaux sont séparés spatialement. </li><li> aligner soigneusement BS5 pour faire en sorte que la direction d&#39;incidence des deux faisceaux est perpendiculaire au plan des pixels du SLM, BS3 et BS4 ignorer au début. Dans un premier temps , rien est affiché sur le SLM, à savoir, elle agit comme un miroir jusqu&#39;à la fin de l&#39;étalonnage (tout au long de l&#39; étape 2). </li><li> Ajustez la position et la distance entre les deux lentilles (L) constituant un télescope Keplerian afin d&#39;obtenir une image nette du plan SLM sur la caméra semi-conducteur complémentaire métal-oxyde (CMOS). Regardez l&#39;orientation correcte de L1 et L2 (côtés plats se font face) pour minimiser les aberrations. </li></ol></li><li> Préparation du côté distal <ol><li> Utilisez BS7 pour diviser le faisceau d&#39;objet en deux faisceaux et les combiner à BS8 employant deux miroirs. Encore une fois, ajuster les séparateurs de faisceaux et mirrors de sorte que les deux faisceaux sont séparés spatialement. </li><li> Détourner les deux faisceaux en utilisant BS9 pour les viser à l&#39;objectif du microscope (OBJ). Concentrer OBJ2 sur l&#39;extrémité distale de la fibre multimode (MMF). Vérifiez la mise au point en observant le reflet de retour de la MMF employant L3 et un dispositif (CCD) à couplage de charge. </li></ol></li><li> Connexion proximale et distale <ol><li> Collimater la lumière du faisceau objet sortant du MMF employant OBJ1. </li><li> Diviser le faisceau objet en utilisant BS6, ignorer le polariseur linéaire (LP) au premier abord. Combiner les deux faisceaux d&#39;objets avec les deux faisceaux de référence à BS3 et BS4 employant un miroir. Réglez les séparateurs de faisceau et des miroirs de telle sorte que chaque paire de référence et le chevauchement de faisceau objet au SLM, coupant avec un petit angle (moins de 1 °). </li><li> Veiller à ce que la puissance de la référence et le faisceau objet sont approximativement égales en tournant l&#39;orientation du HWP, selon l&#39;étape 1.1.2. </li><li> Vérifiez l&#39;interférence pattern (hors axe hologramme) à la caméra CMOS et d&#39;ajuster l&#39;angle d&#39;intersection en conséquence. Augmenter l&#39;angle, jusqu&#39;à ce que l&#39;espacement de franges d&#39;interférence est égale à environ la taille de deux pixels de la caméra CMOS. </li><li> Ajustez l&#39;orientation de la LP pour correspondre à la polarisation de l&#39;objet et le faisceau de référence afin d&#39;obtenir un contraste maximum du motif d&#39;interférence dans l&#39;image de la caméra CMOS, de sorte que l&#39;image de la caméra montre des franges distinctes. </li></ol></li></ol> 2. Calibrage du système <ol><li> Calibrage de la relation entre les pixels SLM et CMOS <ol><li> Illuminer l&#39;ensemble SLM en utilisant seulement l&#39;un des faisceaux de référence et de bloquer les autres objets de référence et les poutres. </li><li> Capturer une image du SLM avec la caméra CMOS. </li><li> Obtenez les coordonnées du coin supérieur gauche de la SLM à l&#39;image de la caméra CMOS, par exemple en utilisant un logiciel graphique et le curseur de la souris sur le PC. Utilisez ces coordonnées de pixel comme point d&#39;origineen ce qui concerne le SLM. </li><li> Retirez tous les blocs de faisceau. </li></ol></li><li> Calibrer les chemins de signaux <ol><li> Bloquer les deux faisceau de référence 2 et faisceau objet 2. </li><li> Capturer une image de l&#39;hologramme avec la caméra CMOS. Évaluer la phase dans l&#39;hologramme enregistré en utilisant la méthode du spectre angulaire 19. Calculer la phase inversée dans la région correspondante du faisceau 1. </li><li> Retirez les anciens blocs de faisceau et maintenant bloquer les deux faisceau de référence 1 et faisceau objet 1. </li><li> Capturer une image de l&#39;hologramme avec la caméra CMOS. Mesurer la phase de l&#39;hologramme enregistré en utilisant à nouveau la méthode de spectre angulaire. Calculer la phase inversée à la région correspondante du faisceau 2. </li><li> Retirez tous les blocs de faisceau. </li></ol></li></ol> 3. Transmission des signaux <ol><li> Bloquer le faisceau objet. </li><li> Assembler les images de phases inversées calculées aux régions correspondantes du faisceau 1 et 2 ensemble et afficher laimage entière sur le SLM, généralement en utilisant le port de l&#39;infographie. </li><li> Lancer la modulation des signaux d&#39;entrée 1 et 2 en activant OM1 et OM2. </li><li> Observer les signaux de sortie 1 et 2 sur la caméra CCD. </li></ol>

<ol>
	<li>Richardson, D. J., Fini, J. M., Nelson, L. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Space-division+multiplexing+in+optical+fibres.">Space-division multiplexing in optical fibres.</a> Nat. Photonics. 7 (5), 354-362 (2013).</li><li>Kreysing, M., 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=Dynamic+operation+of+optical+fibres+beyond+the+single-mode+regime+facilitates+the+orientation+of+biological+cells.">Dynamic operation of optical fibres beyond the single-mode regime facilitates the orientation of biological cells.</a> Nat. Commun. 5 (5481), 1-6 (2014).</li><li>Winzer, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scaling+optical+fiber+networks:+Challenges+and+solutions.">Scaling optical fiber networks: Challenges and solutions.</a> Opt. Photonics News. 26 (3), 28-35 (2015).</li><li>Ci&#382;m&#225;r, T., Dholakia, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shaping+the+light+transmission+through+a+multimode+optical+fibre:+complex+transformation+analysis+and+applications+in+biophotonics.">Shaping the light transmission through a multimode optical fibre: complex transformation analysis and applications in biophotonics.</a> Opt. Express. 19 (20), 18871-18884 (2011).</li><li>Boyden, E. S., Zhang, F., Bamberg, E., Nagel, G., Deisseroth, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Millisecond-timescale,+genetically+targeted+optical+control+of+neural+activity.">Millisecond-timescale, genetically targeted optical control of neural activity.</a> Nat. Neurosci. 8 (9), 1263-1268 (2005).</li><li>Philipp, K., 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=Volumetric+HiLo+microscopy+employing+an+electrically+tunable+lens.">Volumetric HiLo microscopy employing an electrically tunable lens.</a> Opt. Express. 24 (13), 15029-15041 (2016).</li><li>B&#252;ttner, L., Leithold, C., Czarske, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interferometric+velocity+measurements+through+a+fluctuating+gas-liquid+interface+employing+adaptive+optics.">Interferometric velocity measurements through a fluctuating gas-liquid interface employing adaptive optics.</a> Opt. Express. 21 (25), 30653-30663 (2013).</li><li>Vellekoop, I. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Feedback-based+wavefront+shaping.">Feedback-based wavefront shaping.</a> Opt. Express. 23 (9), 12189-12206 (2015).</li><li>Mahalati, R. N., Askarov, D., Wilde, J. P., Kahn, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adaptive+control+of+input+field+to+achieve+desired+output+intensity+profile+in+multimode+fiber+with+random+mode+coupling.">Adaptive control of input field to achieve desired output intensity profile in multimode fiber with random mode coupling.</a> Opt. Express. 20 (13), 14321-14337 (2012).</li><li>Caravaca-Aguirre, A. M., Niv, E., Conkey, D. B., Piestun, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real-time+resilient+focusing+through+a+bending+multimode+fiber.">Real-time resilient focusing through a bending multimode fiber.</a> Opt. Express. 21 (10), 12881-12887 (2013).</li><li>Ci&#382;m&#225;r, T., Dholakia, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exploiting+multimode+waveguides+for+pure+fibre-based+imaging.">Exploiting multimode waveguides for pure fibre-based imaging.</a> Nat. Commun. 3, 1027 (2012).</li><li>Yaqoob, Z., Psaltis, D., Feld, M. S., Yang, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optical+phase+conjugation+for+turbidity+suppression+in+biological+samples.">Optical phase conjugation for turbidity suppression in biological samples.</a> Nat. Photonics. 2 (2), 110-115 (2008).</li><li>Ma, C., Xu, X., Liu, Y., Wang, L. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Time-reversed+adapted-perturbation+(TRAP)+optical+focusing+onto+dynamic+objects+inside+scattering+media.">Time-reversed adapted-perturbation (TRAP) optical focusing onto dynamic objects inside scattering media.</a> Nat. Photonics. 8 (12), 931-936 (2014).</li><li>Lee, K., Lee, J., Park, J. H., Park, J. H., Park, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=One-wave+optical+phase+conjugation+mirror+by+actively+coupling+arbitrary+light+fields+into+a+single-mode+reflector.">One-wave optical phase conjugation mirror by actively coupling arbitrary light fields into a single-mode reflector.</a> Phys. Rev. Lett. 115 (15), 153902 (2015).</li><li>Cui, M., Yang, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Implementation+of+a+digital+optical+phase+conjugation+system+and+its+application+to+study+the+robustness+of+turbidity+suppression+by+phase+conjugation.">Implementation of a digital optical phase conjugation system and its application to study the robustness of turbidity suppression by phase conjugation.</a> Opt. Express. 18 (4), 3444-3455 (2010).</li><li>Hillman, T. R., 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=Digital+optical+phase+conjugation+for+delivering+two-dimensional+images+through+turbid+media.">Digital optical phase conjugation for delivering two-dimensional images through turbid media.</a> Sci. Rep. 3, (2013).</li><li>Papadopoulos, I. N., Farahi, S., Moser, C., Psaltis, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Focusing+and+scanning+light+through+a+multimode+optical+fiber+using+digital+phase+conjugation.">Focusing and scanning light through a multimode optical fiber using digital phase conjugation.</a> Opt. Express. 20 (10), 10583-10590 (2012).</li><li>Czarske, J. W., Haufe, D., Koukourakis, N., B&#252;ttner, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transmission+of+independent+signals+through+a+multimode+fiber+using+digital+optical+phase+conjugation.">Transmission of independent signals through a multimode fiber using digital optical phase conjugation.</a> Opt. Express. 24 (13), 15128-15136 (2016).</li><li>Kim, M. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Principles+and+techniques+of+digital+holographic+microscopy.">Principles and techniques of digital holographic microscopy.</a> SPIE Rev. 1 (1), 01800501-01800550 (2010).</li><li>Gu, R. Y., Mahalati, R. N., Kahn, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Design+of+flexible+multi-mode+fiber+endoscope.">Design of flexible multi-mode fiber endoscope.</a> Opt. Express. 23 (21), 26905-26918 (2015).</li><li>Katz, O., Small, E., Bromberg, Y., Silberberg, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Focusing+and+compression+of+ultrashort+pulses+through+scattering+media.">Focusing and compression of ultrashort pulses through scattering media.</a> Nat. Photonics. 5 (6), 372-377 (2011).</li></ol>

The authors have nothing to disclose.

L&#39;assemblage du dispositif expérimental (étape 1 dans le protocole) nécessite un alignement intime des composants optiques par rapport à l&#39;autre. L&#39;aspect le plus important est l&#39;incidence rectangulaire des faisceaux de référence sur le SLM afin d&#39;assurer un haut PBR. Afin d&#39;améliorer la configuration à plus de deux signaux transmis, séparateurs de faisceaux supplémentaires pourraient être utilisés. Comme alternative, une mise en œuvre à base de fibres s...

La transmission des signaux lumineux multiples à travers une fibre multimode (MMF) est évidente dans les communications d&#39; ingénierie 1 et 2 biophotonique. Dans l&#39;ingénierie des communications, l&#39;espace de multiplexage par répartition (SDM) est considéré comme une solution viable afin d&#39;améliorer la capacité de transmission des fibres optiques pour les futures applications de transfert de données bénéficiant d&#39;une plus grande utilisation de l&#39;espace limité, par rapport à de multiples fibres monomodes 3. Dans la biophotonique, les échantillons biologiques sont manipulés par transmission de la lumière à travers un endoscope MMF 4. Par exemple, le contrôle optique indépendant de neurones individuels en utilisant endoscopes MMF est intéressant pour optogénétique afin d&#39;étudier les réseaux neuronaux dans le cerveau 5. Cependant, la lumière projetée sur la facette d&#39;entrée MMF est soumise à une distorsion due au mode de mélange et de dispersion lors de la propagation à l&#39;output facette de la MMF. Par conséquent, la propagation de la lumière est modifiée, ce qui rend difficile la transmission du signal. Les méthodes de mise en forme Wavefront 6, 7 sont appliquées dans la diffusion des médias en utilisant des modulateurs spatiaux de lumière (SLM) et permettent la compensation de la distorsion due à la diffusion lors de propagation de la lumière 8. Il existe des approches itératives qui optimisent la sortie en utilisant une rétroaction optique 9. Ces approches sont assez de temps à cause de la nécessité de nombreuses itérations et le degré élevé de liberté, correspondant à un grand nombre d&#39;éléments de modulateur. Une autre approche consiste à déterminer complètement la distorsion dans le MMF décrit par sa matrice de transmission 10. Si le nombre de modes à transmettre est important, ce sera beaucoup de temps aussi bien. A l&#39;inverse, la conjugaison de phase optique numérique (DOPC) est considéré commerapide et avantageuse ici, puisque seulement quelques points focaux doivent être générés à la facette de sortie du MMF. Des approches de conjugaison de phase a également été démontrée pour la focalisation ou de l&#39; imagerie à travers un tissu biologique 12, 13, 14. Jusqu&#39;à présent, DOPC a été utilisé pour un signal temporel unique 15, 16, et a été appliqué pour la transmission de la lumière à travers un MMF 17. Une approche de DOPC pour plusieurs signaux indépendants n&#39;a pas été accompli. Nous avons développé une méthode de DOPC améliorée fournissant la transmission indépendante de multiples signaux de lumière utilisant front d&#39; onde individuelle de mise en forme pour chaque signal en utilisant une seule phase seulement SLM 18. Dans ce but, le SLM est segmentée en régions, une pour chaque signal à transmettre. Le montage expérimental proposé est représenté sur la figure 1Où un étalonnage est réalisé en a) avant la transmission réelle se produit en b). <img alt="Figure 1" src="/files/ftp_upload/55407/55407fig1.jpg" /> Figure 1: Montage expérimental. BS = diviseur de faisceau, un dispositif à couplage de charge CCD =, OM = modulateur optique, CMOS = semi-conducteur complémentaire métal-oxyde, HWP = plaque demi-onde, L = objectif, LP = polariseur linéaire, MMF = fibre multimode, objectif OBJ = microscope, PBS = diviseur de faisceau polarisant, SLM = modulateur spatial de lumière (phase uniquement) - seuls faisceaux pertinents pour (a) l&#39;étalonnage et (b) la transmission sont représentés <a href="http://ecsource.jove.com/files/ftp_upload/55407/55407fig1large.jpg" target="_blank">S&#39;il vous plaît cliquer ici pour voir une version plus grande de cette figure.</a>

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>spatial light modulator</td>
			<td>Holoeye</td>
			<td>PLUTO&#8208;VIS&#8208;016</td>
			<td></td>
		</tr>
		<tr>
			<td>CMOS camera</td>
			<td>Mikrotron</td>
			<td>MC4082</td>
			<td></td>
		</tr>
		<tr>
			<td>diode&#8208;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&#8208;3482LE&#8208;M</td>
			<td>CMOS 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&#8208;180&#8208;A&#8208;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&#8208;03&#8208;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&#8208;532</td>
			<td>2x</td>
		</tr>
		<tr>
			<td>linear polarizer</td>
			<td>Thorlabs</td>
			<td>LPVISB050&#8208;MP2</td>
			<td></td>
		</tr>
		<tr>
			<td>optical modulators</td>
			<td>Thorlabs</td>
			<td>MC2000B&#8208;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&#8208;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 colspan="2">adapter for CCD camera to 1 post</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

La transmission de signaux optiques indépendants multiples à travers une fibre optique multimode est réalisée en utilisant la mise en forme de front d&#39;onde afin de compenser la distorsion de la lumière lors de la propagation dans la fibre. Notre méthodologie est basée sur la conjugaison de phase numérique optique utilisant un seul modulateur de lumière spatiale, où le front d&#39;onde optique est modulée individuellement à différentes régions du modulateur, une région par signal lumineux. approches de conjugaison de phase optique numérique sont considérés comme plus rapide que d&#39;autres approches de mise en forme de front d&#39;onde, où (par exemple) une détermination complète du comportement de propagation des ondes de la fibre est réalisée. En revanche, l&#39;approche présentée est temps efficace car il ne nécessite qu&#39;un seul étalonnage par signal lumineux. La méthode proposée est potentiellement approprié pour l&#39;espace de multiplexage par répartition dans l&#39;ingénierie des communications. domaines d&#39;application supplémentaires sont la livraison de la lumière endoscopique en biophotonique, en particulier dans optogenetics, où des cellules individuelles dans les tissus biologiques doivent être éclairés de manière sélective avec une résolution spatiale et temporelle.

<html> Des signaux de sortie typiques du côté distal du 2 m de longueur de fibre sont représentés sur la figure 2. Notez que la tache focale souhaitée (pic) est accompagné d&#39;un motif moucheté indésirable (fond), qui est due à l&#39;imperfection de la DOPC comme une question de principe. Le rapport de crête à fond correspondant (PBR) se monte à 53 (uniquement le signal 1 est &#39;on&#39;), 36 (uniquement le signal 2 est «on») et 20 (les deux signaux 1 et ...

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.

Transmission des signaux multiples à travers une fibre optique utilisant Wavefront Shaping

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

Research

Education

JoVE Core

JoVE Journal

Electrical Engineering

Bioengineering

Unit 1

Diagrams and Signal Flow Graphs

SCIENTISTS IN ACTION

9.7K vues.  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.

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

Three-dimensional Optical-resolution Photoacoustic Microscopy

Optical microscopy, providing valuable insights at the cellular and organelle levels, has been widely recognized as an enabling biomedical technology. As the mainstays of in vivo three-dimensional (3-D) optical microscopy, single-/multi-photon fluorescence microscopy and optical coherence tomography (OCT) have demonstrated their extraordinary sensitivities to fluorescence and optical scattering contrasts, respectively. However, the optical absorption contrast of biological tissues, which encodes essential physiological/pathological information, has not yet been assessable. 
The emergence of biomedical photoacoustics has led to a new branch of optical microscopy optical-resolution photoacoustic microscopy (OR-PAM)1, where the optical irradiation is focused to the diffraction limit to achieve cellular1 or even subcellular2 level lateral resolution. As a valuable complement to existing optical microscopy technologies, OR-PAM brings in at least two novelties. First and most importantly, OR-PAM detects optical absorption contrasts with extraordinary sensitivity (i.e., 100%). Combining OR-PAM with fluorescence microscopy3 or with optical-scattering-based OCT4 (or with both) provides comprehensive optical properties of biological tissues. Second, OR-PAM encodes optical absorption into acoustic waves, in contrast to the pure optical processes in fluorescence microscopy and OCT, and provides background-free detection. The acoustic detection in OR-PAM mitigates the impacts of optical scattering on signal degradation and naturally eliminates possible interferences (i.e., crosstalks) between excitation and detection, which is a common problem in fluorescence microscopy due to the overlap between the excitation and fluorescence spectra. 
Unique for optical absorption imaging, OR-PAM has demonstrated broad biomedical applications since its invention, including, but not limited to, neurology5, 6, ophthalmology7, 8, vascular biology9, and dermatology10. In this video, we teach the system configuration and alignment of OR-PAM as well as the experimental procedures for in vivo functional microvascular imaging.

Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging technology capable of imaging optical absorption contrasts in vivo with cellular resolution and sensitivity. Here, we provide a visualized instruction on the experimental protocols of OR-PAM, including system configuration, system alignment, typical in vivo experimental procedures, and functional imaging schemes.

Tridimensionnelle optique résolution microscopie photoacoustique

Optical microscopy, providing valuable insights at the cellular and organelle levels, has been widely recognized as an enabling biomedical technology. As ...

Recherche

Bio-ingénierie

Attaching Biological Probes to Silica Optical Biosensors Using Silane Coupling Agents

In order to interface with biological environments, biosensor platforms, such as the popular Biacore system (based on the Surface Plasmon Resonance (SPR) technique), make use of various surface modification techniques, that can, for example, prevent surface fouling, tune the hydrophobicity / hydrophilicity of the surface, adapt to a variety of electronic environments, and most frequently, induce specificity towards a target of interest.1-5 These techniques extend the functionality of otherwise highly sensitive biosensors to real-world applications in complex environments, such as blood, urine, and wastewater analysis.2,6-7 While commercial biosensing platforms, such as Biacore, have well-understood, standard techniques for performing such surface modifications, these techniques have not been translated in a standardized fashion to other label-free biosensing platforms, such as Whispering Gallery Mode (WGM) optical resonators.8-9
WGM optical resonators represent a promising technology for performing label-free detection of a wide variety of species at ultra-low concentrations.6,10-12 The high sensitivity of these platforms is a result of their unique geometric optics: WGM optical resonators confine circulating light at specific, integral resonance frequencies.13 Like the SPR platforms, the optical field is not totally confined to the sensor device, but evanesces; this "evanescent tail" can then interact with species in the surrounding environment. This interaction causes the effective refractive index of the optical field to change, resulting in a slight, but detectable, shift in the resonance frequency of the device. Because the optical field circulates, it can interact many times with the environment, resulting in an inherent amplification of the signal, and very high sensitivities to minor changes in the environment.2,14-15
To perform targeted detection in complex environments, these platforms must be paired with a probe molecule (usually one half of a binding pair, e.g. antibodies / antigens) through surface modification.2 Although WGM optical resonators can be fabricated in several geometries from a variety of material systems, the silica microsphere is the most common. These microspheres are generally fabricated on the end of an optical fiber, which provides a "stem" by which the microspheres can be handled during functionalization and detection experiments. Silica surface chemistries may be applied to attach probe molecules to their surfaces; however, traditional techniques generated for planar substrates are often not adequate for these three-dimensional structures, as any changes to the surface of the microspheres (dust, contamination, surface defects, and uneven coatings) can have severe, negative consequences on their detection capabilities. Here, we demonstrate a facile approach for the surface functionalization of silica microsphere WGM optical resonators using silane coupling agents to bridge the inorganic surface and the biological environment, by attaching biotin to the silica surface.8,16 Although we use silica microsphere WGM resonators as the sensor system in this report, the protocols are general and can be used to functionalize the surface of any silica device with biotin.

Biosensors interface with complex, biological environments and perform targeted detection by combining highly sensitive sensors with highly specific probes attached to the sensor via surface modification. Here, we demonstrate the surface functionalization of silica optical sensors with biotin using silane coupling agents to bridge the sensor and the biological environment.

Fixation des sondes biologiques à des biocapteurs optiques de silice à l&#39;aide d&#39;agents de couplage au silane

In order to interface with biological environments, biosensor platforms, such as the popular Biacore system (based on the Surface Plasmon Resonance (SPR) ...

Induction of Adhesion-dependent Signals Using Low-intensity Ultrasound

In multicellular organisms, cell behavior is dictated by interactions with the extracellular matrix. Consequences of matrix-engagement range from regulation of cell migration and proliferation, to secretion and even differentiation. The signals underlying each of these complex processes arise from the molecular interactions of extracellular matrix receptors on the surface of the cell. Integrins are the prototypic receptors and provide a mechanical link between extracellular matrix and the cytoskeleton, as well as initiating some of the adhesion-dependent signaling cascades. However, it is becoming increasingly apparent that additional transmembrane receptors function alongside the integrins to regulate both the integrin itself and signals downstream. The most elegant of these examples is the transmembrane proteoglycan, syndecan-4, which cooperates with &alpha;5&beta;1-integrin during adhesion to fibronectin. In vivo models demonstrate the importance of syndecan-4 signaling, as syndecan-4-knockout mice exhibit healing retardation due to inefficient fibroblast migration1,2. In wild-type animals, migration of fibroblasts toward a wound is triggered by the appearance of fibronectin that leaks from damaged capillaries and is deposited by macrophages in injured tissue. Therefore there is great interest in discovering strategies that enhance fibronectin-dependent signaling and could accelerate repair processes.
The integrin-mediated and syndecan-4-mediated components of fibronectin-dependent signaling can be separated by stimulating cells with recombinant fibronectin fragments. Although integrin engagement is essential for cell adhesion, certain fibronectin-dependent signals are regulated by syndecan-4. Syndecan-4 activates the Rac1 protrusive signal3, causes integrin redistribution1, triggers recruitment of cytoskeletal molecules, such as vinculin, to focal adhesions4, and thereby induces directional migration3. We have looked for alternative strategies for activating such signals and found that low-intensity pulsed ultrasound (LIPUS) can mimic the effects of syndecan-4 engagement5. In this protocol we describe the method by which 30 mW/cm2, 1.5 MHz ultrasound, pulsed at 1 kHz (Fig. 1) can be applied to fibroblasts in culture (Fig. 2) to induce Rac1 activation and focal adhesion formation. Ultrasound stimulation is applied for a maximum of 20 minutes, as this combination of parameters has been found to be most efficacious for acceleration of clinical fracture repair6. The method uses recombinant fibronectin fragments to engage &alpha;5&beta;1-integrin, without engagement of syndecan-4, and requires inhibition of protein synthesis by cycloheximide to block deposition of additional matrix by the fibroblasts., The positive effect of ultrasound on repair mechanisms is well documented7,8, and by understanding the molecular effect of ultrasound in culture we should be able to refine the therapeutic technique to improve clinical outcomes.

This protocol describes the stimulation of cultured fibroblasts with low-intensity pulsed ultrasound, which drives focal adhesion formation and Rac1 activation by mimicking engagement of the transmembrane matrix receptor, syndecan-4. This approach allows investigation of a successful clinical technique at the cellular level, thereby providing opportunities for refinement of the therapy.

L&#39;induction de signaux d&#39;adhésion dépendant de l&#39;aide ultrasons à faible intensité

In multicellular organisms, cell behavior is dictated by interactions with the extracellular matrix. Consequences of matrix-engagement range from ...

In vitro Synthesis of Native, Fibrous Long Spacing and Segmental Long Spacing Collagen

Collagen fibrils are present in the extracellular matrix of animal tissue to provide structural scaffolding and mechanical strength. These native collagen fibrils have a characteristic banding periodicity of ~67 nm and are formed in vivo through the hierarchical assembly of Type I collagen monomers, which are 300 nm in length and 1.4 nm in diameter. In vitro, by varying the conditions to which the monomer building blocks are exposed, unique structures ranging in length scales up to 50 microns can be constructed, including not only native type fibrils, but also fibrous long spacing and segmental long spacing collagen. Herein, we present procedures for forming the three different collagen structures from a common commercially available collagen monomer. Using the protocols that we and others have published in the past to make these three types typically lead to mixtures of structures. In particular, unbanded fibrils were commonly found when making native collagen, and native fibrils were often present when making fibrous long spacing collagen. These new procedures have the advantage of producing the desired collagen fibril type almost exclusively. The formation of the desired structures is verified by imaging using an atomic force microscope.

In vitro Synthesis of Native, Fibrous Long Spacing and Segmental Long Spacing Collagen

Simple and reproducible procedures are described for making three structurally distinct collagen assemblies from a common commercially available Type I collagen monomer. Native type, fibrous long spacing or segmental long spacing collagen can be constructed by varying the conditions to which the 300 nm long and 1.4 nm diameter monomer building block is exposed.

En synthèse in vitro de la maternelle, de l&#39;espacement de longue fibreux et segmentaire collagène Espacement long

Collagen fibrils are present in the  extracellular matrix of animal tissue to provide structural scaffolding and  mechanical strength. These native ...

Label-free Single Molecule Detection Using Microtoroid Optical Resonators

Detecting small concentrations of molecules down to the single molecule limit has impact on areas such as early detection of disease, and fundamental studies on the behavior of molecules. Single molecule detection techniques commonly utilize labels such as fluorescent tags or quantum dots, however, labels are not always available, increase cost and complexity, and can perturb the events being studied. Optical resonators have emerged as a promising means to detect single molecules without the use of labels. Currently the smallest particle detected by a non-plasmonically-enhanced bare optical resonator system in solution is a 25 nm polystyrene sphere1. We have developed a technique known as Frequency Locking Optical Whispering Evanescent Resonator (FLOWER) that can surpass this limit and achieve label-free single molecule detection in aqueous solution2. As signal strength scales with particle volume, our work represents a &#62; 100x improvement in the signal to noise ratio (SNR) over the current state of the art. Here the procedures behind FLOWER are presented in an effort to increase its usage in the field.

We have developed a label-free biosensing system based on optical resonator technology known as Frequency Locking Optical Whispering Evanescent Resonator (FLOWER) that is capable of detecting single molecules in solution. Here the procedures behind this work are described and presented.

Simple détection de molécule libre Label-Utilisation Microtoroid optiques résonateurs

Detecting small concentrations of molecules down to the single molecule limit has impact on areas such as early detection of disease, and fundamental ...

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.

Multicolor détection Fluorescence pour Droplet microfluidique utilisant des fibres optiques

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

Determination of Zeta Potential via Nanoparticle Translocation Velocities through a Tunable Nanopore: Using DNA-modified Particles as an Example

Nanopore technologies, known collectively as Resistive Pulse Sensors (RPS), are being used to detect, quantify and characterize proteins, molecules and nanoparticles. Tunable resistive pulse sensing (TRPS) is a relatively recent adaptation to RPS that incorporates a tunable pore that can be altered in real time. Here, we use TRPS to monitor the translocation times of DNA-modified nanoparticles as they traverse the tunable pore membrane as a function of DNA concentration and structure (i.e., single-stranded to double-stranded DNA).
TRPS is based on two Ag/AgCl electrodes, separated by an elastomeric pore membrane that establishes a stable ionic current upon an applied electric field. Unlike various optical-based particle characterization technologies, TRPS can characterize individual particles amongst a sample population, allowing for multimodal samples to be analyzed with ease. Here, we demonstrate zeta potential measurements via particle translocation velocities of known standards and apply these to sample analyte translocation times, thus resulting in measuring the zeta potential of those analytes.
As well as acquiring mean zeta potential values, the samples are all measured using a particle-by-particle perspective exhibiting more information on a given sample through sample population distributions, for example. Of such, this method demonstrates potential within sensing applications for both medical and environmental fields.

Here we use a polyurethane tunable nanopore integrated into a resistive pulse sensing technique to characterize nanoparticles surface chemistry via the measurement of particle translocation velocities, which can be used to determine the zeta potential of individual nanoparticles.

Détermination du potentiel Zeta via nanoparticulaires translocation Velocities à travers un accordable Nanopore: Utilisation de particules d&#39;ADN modifié comme un exemple

Nanopore technologies, known collectively as Resistive Pulse Sensors (RPS), are being used to detect, quantify and characterize proteins, molecules and ...

Using Extraordinary Optical Transmission to Quantify Cardiac Biomarkers in Human Serum

For a biosensing platform to have clinical relevance in point-of-care (POC) settings, assay sensitivity, reproducibility, and ability to reliably monitor analytes against the background of human serum are crucial.
Nanoimprinting lithography (NIL) was used to fabricate, at a low cost, sensing areas as large as 1.5 mm x 1.5 mm. The sensing surface was made of high-fidelity arrays of nanoholes, each with an area of about 140 nm2. The great reproducibility of NIL made it possible to employ a one-chip, one-measurement strategy on 12 individually manufactured surfaces, with minimal chip-to-chip variation. These nanoimprinted localized surface plasmon resonance (LSPR) chips were extensively tested on their ability to reliably measure a bioanalyte at concentrations varying from 2.5 to 75 ng/mL amidst the background of a complex biofluid-in this case, human serum. The high fidelity of NIL enables the generation of large sensing areas, which in turn eliminates the need for a microscope, as this biosensor can be easily interfaced with a commonly available laboratory light source. These biosensors can detect cardiac troponin in serum with a high sensitivity, at a limit of detection (LOD) of 0.55 ng/mL, which is clinically relevant. They also show low chip-to-chip variance (due to the high quality of the fabrication process). The results are commensurable with widely used enzyme-linked immunosorbent assay (ELISA)-based assays, but the technique retains the advantages of an LSPR-based sensing platform (i.e., amenability to miniaturization and multiplexing, making it more feasible for POC applications).

This work describes a nanoimprinting lithography method to fabricate high-quality sensing arrays that work on the principle of extraordinary optical transmission. The biosensor is low-cost, robust, easy to use, and can detect cardiac troponin I in serum at clinically relevant concentrations (99th percentile cutoff &#8764;10-400 pg/mL, depending on the assay).

À l’aide de Transmission optique extraordinaire pour quantifier les biomarqueurs cardiaques dans le sérum humain

For a biosensing platform to have clinical relevance in point-of-care (POC) settings, assay sensitivity, reproducibility, and ability to reliably monitor ...

Targeting Neuronal Fiber Tracts for Deep Brain Stimulation Therapy Using Interactive, Patient-Specific Models

Deep brain stimulation (DBS), which involves insertion of an electrode to deliver stimulation to a localized brain region, is an established therapy for movement disorders and is being applied to a growing number of disorders. Computational modeling has been successfully used to predict the clinical effects of DBS; however, there is a need for novel modeling techniques to keep pace with the growing complexity of DBS devices. These models also need to generate predictions quickly and accurately. The goal of this project is to develop an image processing pipeline to incorporate structural magnetic resonance imaging (MRI) and diffusion weighted imaging (DWI) into an interactive, patient specific model to simulate the effects of DBS. A virtual DBS lead can be placed inside of the patient model, along with active contacts and stimulation settings, where changes in lead position or orientation generate a new finite element mesh and solution of the bioelectric field problem in near real-time, a timespan of approximately 10 seconds. This system also enables the simulation of multiple leads in close proximity to allow for current steering by varying anodes and cathodes on different leads. The techniques presented in this paper reduce the burden of generating and using computational models while providing meaningful feedback about the effects of electrode position, electrode design, and stimulation configurations to researchers or clinicians who may not be modeling experts.

The goal of this project is to develop an interactive, patient-specific modeling pipeline to simulate the effects of deep brain stimulation in near real-time and provide meaningful feedback as to how these devices influence neural activity in the brain.

Ciblage des fibres neuronales Tracts pour la thérapie de Stimulation cérébrale profonde à l’aide de modèles interactifs, spécifiques à un Patient

Deep brain stimulation (DBS), which involves insertion of an electrode to deliver stimulation to a localized brain region, is an established therapy for ...

Screening and Identification of Small Peptides Targeting Fibroblast Growth Factor Receptor2 using a Phage Display Peptide Library

The human Fibroblast Growth Factor Receptor (FGFR) family comprises four members, namely, FGFR1, FGFR2, FGFR3, and FGFR4, that are involved in various biological activities including cell proliferation, survival, migration and differentiation. Several aberrations in the FGFR signaling pathway, owing to mutations or gene amplification events, have been identified in various types of cancers. Hence, recent research has focused on developing strategies involving therapeutic targeting of FGFRs. Current FGFR inhibitors at various stages of pre-clinical and clinical development include either small molecule inhibitors of tyrosine kinases or monoclonal antibodies, with only a few peptide- based inhibitors in the pipeline. Here, we provide a protocol using phage display technology to screen small peptides as antagonists of FGFR2. Briefly, a library of phage-displayed peptides was incubated in a plate coated with FGFR2. Subsequently, unbound phage was washed off by TBST (TBS + 0.1% [v/v] Tween-20), and bound phage was eluted with 0.2 M glycine-HCl buffer (pH 2.2). The eluted phage was further amplified and used as input for the next round of biopanning. Following three rounds of biopanning, the peptide sequences of individual phage clones were identified by DNA sequencing. Finally, the screened peptides were synthesized and analyzed for affinity and biological activity.

Herein, we present a detailed protocol for screening small peptides that bind to FGFR2 using a phage display peptide library. We further analyze the affinity of the selected peptides toward FGFR2 in vitro and its ability to suppress cell proliferation.

Dépistage et identification des petits peptides ciblant le récepteur du facteur de croissance du fibroblaste2 à l'aide d'une bibliothèque de peptides d'affichage de phage

The human Fibroblast Growth Factor Receptor (FGFR) family comprises four members, namely, FGFR1, FGFR2, FGFR3, and FGFR4, that are involved in various ...