Name: writing bragg gratings in multicore fibers
Uploaded: 2016-04-20T14:00:00
Description: Watch this Scientific Journal Video about Writing Bragg Gratings in Multicore Fibers at JoVE.com

The SAIL labs are funded through JBH's Australian Laureate Fellowship from the Australian Research Council.
This research was supported by the Australian Research Council Centre of Excellence for Ultrahigh bandwidth Devices for Optical Systems (project number CE110001018).
Experimental work was performed in part at the OptoFab node of the Australian National Fabrication Facility, utilizing NCRIS and NSW state government funding. Fiber hydrogenation services were provided by TE Connectivity in Redfern. SLS would like to acknowledge the Optics and Electronics Laboratory, Fujikura Ltd, Japan for providing the 7-core fiber used in this experiment.

1. إعداد ملمع شعري أنابيب (ANFF OptoFab) <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> الحصول على أنابيب زجاجية الشعرية مع القطر الداخلي يقابل ارتباطا وثيقا قطرها الألياف. وأقرب في الحجم، وأفضل أداء، ولكن تأكد من أن يسمح الاختلاف ± 10 ميكرون في حجم الشعرية ل. إزالة أي الط?...

<ol>
	<li>Othonos, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fiber+Bragg+gratings.">Fiber Bragg gratings.</a> Rev. Sci. Instrum. 68 (12), 4309-4341 (1997).</li><li>Bland-Hawthorn, J., Englund, M., Edvell, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+approach+to+atmospheric+OH+suppression+using+an+aperiodic+fiber+Bragg+grating.">New approach to atmospheric OH suppression using an aperiodic fiber Bragg grating.</a> Opt. Express. 12 (24), 5902-5909 (2004).</li><li>Jovanovic, N., Guyon, O., Martinache, F., Schwab, C., Cvetojevic, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+to+inject+light+efficiently+into+single-mode+fibers.">How to inject light efficiently into single-mode fibers.</a> Proc. SPIE. 9147, 91477P (2014).</li><li>Bland-Hawthorn, J., 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=A+complex+multi-notch+astronomical+filter+to+suppress+the+bright+infrared+sky.">A complex multi-notch astronomical filter to suppress the bright infrared sky.</a> Nat. Comm. 2, 581 (2011).</li><li>Leon-Saval, S. G., Argyros, A., Bland-Hawthorn, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photonic+lanterns.">Photonic lanterns.</a> Opt. Express. 18 (8), 8430-8439 (2010).</li><li>Trinh, C. Q., 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=GNOSIS:+the+first+instrument+to+use+fiber+Bragg+gratings+for+OH+suppression.">GNOSIS: the first instrument to use fiber Bragg gratings for OH suppression.</a> Astron. J. 145 (2), 51 (2013).</li><li>Content, 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=PRAXIS:+low+thermal+emission+high+efficiency+OH+suppressed+fiber+spectrograph.">PRAXIS: low thermal emission high efficiency OH suppressed fiber spectrograph.</a> Proc. SPIE. 9151, 91514W (2014).</li><li>Birks, T. A., Mangan, B. J., D&#236;ez, A., Cruz, J. L., Murphy, D. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photonic+lantern'+spectral+filters+in+multi-core+fiber.">Photonic lantern' spectral filters in multi-core fiber.</a> Opt. Express. 20 (13), 13996-14008 (2012).</li><li>Askins, C., 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=Inscription+of+fiber+Bragg+gratings+in+multicore+fiber.">Inscription of fiber Bragg gratings in multicore fiber.</a> BGPP. , JWA39 (2007).</li><li>Lindley, E., 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=Core-to-core+uniformity+improvement+in+multicore+fiber+Bragg+gratings.">Core-to-core uniformity improvement in multicore fiber Bragg gratings.</a> Proc. SPIE. 9151, 91515F (2014).</li><li>Lindley, E., 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=Demonstration+of+uniform+multicore+fiber+Bragg+gratings.">Demonstration of uniform multicore fiber Bragg gratings.</a> Opt. Express. 22 (25), 31575-31581 (2014).</li><li>Tomaru, S., Yasu, M., Kawachi, M., Edahiro, T. V. A. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=VAD+single-mode+fiber+with+0.2+dB/km+loss.">VAD single-mode fiber with 0.2 dB/km loss.</a> Elec. Lett. 17 (2), 93-93 (1981).</li></ol>

أرقام 2 و 3 تظهر معا أن إدخال الأنابيب الشعرية مصقول (PCT) عند كتابة حواجز شبكية غير كافية لتحسين توحيد أطياف الأساسية في MCFBG. ما تبقى من عملية الكتابة هي دون تغيير إلى حد كبير من الطرق التي أنشئت لخلق حواجز شبكية SMF، ويمكن استخدامها مع معظم أنظمة الكتاب?...

وتستخدم حواجز شبكية الألياف براج (FBGs) على نطاق واسع مرشحات الضيق يرجع ذلك إلى حقيقة أنها يمكن أن تكون مخصصة لعدد كبير من التطبيقات 1. وهي لا تقتصر على قمع موجات واحدة؛ يمكن إنشاء الأطياف انتقال معقد عن طريق استخدام ادوري الاختلافات معامل الانكسار 2. واحد الحد هو أن FBGs يمكن المدرج فقط في الألياف أحادية النمط (SMFs)، والطول الموجي الذي يتعرض للكبت لفترة صريف معين يعتمد على الانتشار الثابت. في الألياف متعددة (MMF)، حيث كل واسطة لديه ثابت نشر مختلفة، والطول الموجي قمعها لكل وضع مختلف، وبالتالي صريف لا يعطي قمع قوي في أي طول موجي واحد. الزخم لهذه التجربة يأتي من علم الفلك. في ظل ظروف محدودة الرؤية، واقتران مباشر إلى مفصل من الصعب وغير فعالة. مطلوبة البصريات التكيفية المتطرفة للقيام بذلك 3. وبسبب هذا، MMFs هي الطباعتستخدم ically عند جمع الضوء من طائرة الوصل التلسكوب 4. لذلك من اجل الحفاظ على وظيفة متاحة فقط للSMFs، فمن الضروري أن يكون التحويل الفعال بين SMFs وMMFs. وقد أصبح هذا ممكنا مع فانوس الضوئية، وهو الجهاز الذي يتكون من ميناء المتعدد متصلة مجموعة من SMFs عبر الانتقال تفتق 5. استخدمت الفوانيس الضوئية في الصك الغنوص، الذي SMFs الواردة FBGs لإزالة خطوط الانبعاثات في الغلاف الجوي (الذي تسببه الجذور OH والجزيئات الأخرى) من الملاحظات الأشعة تحت الحمراء القريبة 6. عيوب استخدام الفردية، SMFs أحادية النواة لهذه المهمة هي أنها يجب أن تكون مكتوبة واحدا تلو الآخر وتقسم بشكل فردي في القطار البصرية، والتي تتطلب قدرا كبيرا من الوقت والجهد اليدوي. محاولات تقنية الموضحة في هذه المقالة لمعالجة هذه العيوب باستخدام تنسيق الألياف أكثر تعقيدا لتوفير وظائف-وضع واحد. الجيل القادم OH supprسوف ession أداة التطبيق العملي 7 الاستفادة من الألياف متعددة النواة (معاملات تحول غاز الميثان). هذه الألياف تحتوي على أي عدد من النوى وحيدة معضد جزءا لا يتجزأ من الكسوة واحدة. وميزة هذا النهج هي أن قدم مكعبة يمكن مدبب إلى MMF مع فانوس الضوئية الناتجة يجري وحدة قائمة بذاتها المدمجة وقوية. في الصك الانتهاء، وعلى ضوء من التلسكوب سوف يقترن بمنفذ MMF من فانوس، فإن الانتقال تفتق فصل هذا الضوء إلى النوى طريقة واحدة حيث أنها سوف تمر عبر FBGs. بعد تفرق الطول الموجي تصفية ضوء المتبقية على كاشف، أطياف جمعها. أيضا بسرعة باستخدام معاملات تحول غاز الميثان بعملية الكتابة حواجز شبكية، وجميع النوى يمكن المدرج في مسار واحد. ومع ذلك، يجب أن يتم تعديل عملية الكتابة من أجل التأكد من أن جميع النوى لديها خصائص التفكير ذاتها. وذلك لأن سطح منحن من الكسوة بمثابة عدسة خلال جنبا كتابة FBGs، قرارulting في مجال الأشعة فوق البنفسجية التي تختلف في السلطة والتوجيه في كل نواة إذا تم استخدام الطريقة القياسية جنبا إلى الكتابة. وبالتالي كل الأساسية سوف يكون لها الشخصية نقل مختلفة، وسوف الألياف لا توفر قمع قوي عند طول موجي واحد 8. جربت مجموعة من مختبر بحوث البحرية مع تعديل التوزيع وحساسية للضوء من النوى لإلغاء آثار هذا الاختلاف 9. الجانب السلبي لاستخدام هذا النهج هو أن الألياف لا بد من إعادة تصميم كل مجموعة من حجم الكسوة، وحجم النواة، وعدد من النوى والتركيب الكيميائي. وبالإضافة إلى ذلك، عدم التناظر المحوري في التصاميم الناتجة يعني أن قدم مكعبة لا يمكن مدبب بشكل فعال إلى MMF مع نواة دائرية. تفاصيل هذه الورقة مقاربة مختلفة للمشكلة: تعديل الحقل داخل الألياف من خلال وجود لها بالمرور من خلال سطح مستو بدلا من أن تكون مباشرة الحادث على الكسوة المنحنية. باستخدام هذا النهج يؤدي إلىالأسلوب الذي هو قابل للتحويل إلى مجموعة متنوعة من التصاميم والأحجام قدم مكعبة، لا سيما الألياف متماثل محوريا التي نود أن تدرج في الفوانيس الضوئية. لإنشاء سطح مستو ضروري، يتم وضع قدم مكعبة داخل الأنابيب الشعرية للأشعة فوق البنفسجية شفافة التي تم الأرض ومصقول على جانب واحد لإعطاء الجدار الخارجي شقة. يجب أن تترك فجوة صغيرة بين الألياف والشعيرات الدموية، حيث أن الأخير قد تحتوي ± 10 ميكرون تغيرات في القطر. انظر الشكل 1 للتمثيل. وتصف هذه الورقة إجراء التجارب لكتابة FBGs بهذه الطريقة، وتقديم أمثلة من التحسينات الممكنة. لمزيد من المعلومات راجع المحاكاة نشرت سابقا 10 والنتائج التجريبية 11. <img alt="الشكل 1" src="/files/ftp_upload/53326/53326fig1.jpg" /> الشكل 1. رسم تخطيطي لأنبوب شعري مصقول كما تستخدم في المنتجات FBGيتم وضع أيون. وقدم مكعبة داخل الأنابيب الشعرية. وينبغي أن تكون الفجوة بين الاثنين صغيرة ولكنها تسمح لالاختلافات الصغيرة في القطر. ضوء الأشعة فوق البنفسجية التي مرت من خلال القناع المرحلة ثم يدخل النظام من خلال الجانب المسطح من الأنابيب الشعرية. <a href="https://www.jove.com/files/ftp_upload/53326/53326fig1large.jpg" target="_blank">الرجاء انقر هنا لعرض نسخة أكبر من هذا الرقم.</a>

<table border="0" cellpadding="0" cellspacing="0" width="1171">
	<tbody>
		<tr height="22">
			<td height="22" style="height:22px;width:216px;">Multicore fiber</td>
			<td style="width:148px;">Fujikura Ltd.</td>
			<td style="width:163px;"></td>
			<td style="width:645px;">7 cores with diameter 5.5 &#181;m, core separation 35 &#181;m, hexagonally arranged within 125 &#181;m cladding, NA = 0.177</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Glass tapering machine</td>
			<td style="width:148px;">Vytran</td>
			<td style="width:163px;">GPX-3000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">UV laser</td>
			<td style="width:148px;">Coherent</td>
			<td style="width:163px;">300 FreD Innova</td>
			<td>Frequency doubled 244 nm, at least 150 mW output. CAUTION: eye damage; wear appropriate goggles</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Phase mask</td>
			<td style="width:148px;">Lasiris</td>
			<td style="width:163px;">PM-244-1069.50-50.8</td>
			<td>Custom component, 1069.50 nm grating period, 5.08 mm thickness</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Capillary tubes</td>
			<td style="width:148px;">Polymicro</td>
			<td>TSP200794</td>
			<td>Inner diameter 200 &#181;m, outer diameter 794 &#181;m</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Lapping machine</td>
			<td style="width:148px;">Logitech</td>
			<td style="width:163px;">PM5</td>
			<td>Combination grinder/polisher</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">UV-curable glue</td>
			<td style="width:148px;">Norland</td>
			<td style="width:163px;">NOA-61</td>
			<td>Cures rapidly, removable with acetone</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Microgrit</td>
			<td style="width:148px;">Eminess</td>
			<td style="width:163px;"></td>
			<td>Al2O3: 25 &#181;m and 5 &#181;m particle size</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Polishing fluid</td>
			<td style="width:148px;">Eminess</td>
			<td style="width:163px;">ULTRA-SOL 500S</td>
			<td>SF-500S-5, ULTRA-SOL 500S N/D, 5 GAL</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Sodium hydroxide</td>
			<td style="width:148px;"></td>
			<td style="width:163px;"></td>
			<td>0.004M</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Fiber cleaver</td>
			<td style="width:148px;">Vytran</td>
			<td style="width:163px;">LDC-400</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Tunable laser</td>
			<td style="width:148px;">JDS Uniphase</td>
			<td style="width:163px;">SWS15101</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">IR Camera</td>
			<td style="width:148px;">Xenics</td>
			<td style="width:163px;">XEVA-1429</td>
			<td>320x256 pixel, 16 bit resolution</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Oven</td>
			<td style="width:148px;">Thermoline Scientific</td>
			<td style="width:163px;">LDO-030N</td>
			<td>For annealing at T=110&#176;C</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Hydrogen gas</td>
			<td style="width:148px;">BOC</td>
			<td style="width:163px;"></td>
			<td>For hydrogenating fiber. CAUTION: flammable, pressurised gas</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Nitrogen gas</td>
			<td style="width:148px;">BOC</td>
			<td style="width:163px;"></td>
			<td>Booster for hydrogenation. CAUTION: pressurised gas</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Acetone</td>
			<td style="width:148px;"></td>
			<td style="width:163px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Razor blades</td>
			<td style="width:148px;"></td>
			<td style="width:163px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

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.

ومن الأفضل أثبتت فعالية هذه التقنية عن طريق مقارنة حواجز شبكية الألياف متعددة النوى براج (MCFBGs) التي تنتج عن التعرض مع وبدون الشعرية ويبين الشكل 2 خصائص انتقال من النواة 7 قدم مكعبة يتعرض باستخدام الطريقة المعيارية لSMFs، مع فرد أطياف الأساسية...

Watch this Scientific Journal Video about Writing Bragg Gratings in Multicore Fibers at JoVE.com

Writing Bragg Gratings in 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.

كتابة براج حواجز شبكية في ألياف متعددة النواة

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

The overall goal of this procedure is to simultaneously inscribe fiber Bragg gratings with matching characteristics into each core of a multi-core fiber. Well this technique allows efficient inscription of multi-core fiber Bragg gratings, and the main advantage of using this method is that it can be performed with the same inscription equipment as for a single mode fiber. Generally individuals new to this method will struggle because it requires a range of skills to fabricate and use the capillary tubes.The idea behind this method came from trying to avoid the lensing effect that happens when the light gets into the fiber at right angles. Demonstrating the procedure will be myself, a PHD student, and Doctor Seong-sik Min, a research fellow in the fiber Bragg grating laboratory. In preparation, taper glass capillary tubes, as described in the text protocol.Then begin by cutting the tapered tubes into approximately equal lengths that are at least two centimeters longer than the intended grating length, but small enough to fit within the polishing equipment. Using a UV curable glue, attach eight to ten of the capillary lengths to a slide, and then attach the slide to a glass puck. Next, install the puck onto a jig compatible with the lapping polishing machine.Now, put on protective gear, and load the lapping polishing machine with 25 micron grit made of aluminum oxide in reverse osmosis purified water. Set the puck into the machine, and make certain it is absolutely parallel to the grinding surface. Grind the capillary tubes until the thickness of the capillary wall is about 70 microns.Use a very accurate micrometer to measure the displacement of the jig during the grinding, and hence the amount of wall that has been removed. Once the wall thickness drops to 70 microns, switch to a five micron grit, and grind the wall down to about 50 microns. Now, swap the grit for a high purity colloidal sillica in alkaline dispersion.Then polish the flattened surface for at least three hours to restore the surface's optical quality. To separate the capillary tubes from the holding puck, soak them overnight in acetone. The next day, examine the capillary tubes at both ends under a microscope with ten times magnification to check the wall thickness.A good quality capillary will have a uniformly thin wall along its length. Prior to beginning, hydrogenate the MCFs to increase their photo sensitivity. Next, strip the protective coating from the MCFs using a standard SMF fiber stripper.Remove the coating from where the grating will be written to the end of the fiber. Then, insert the stripped end of the fiber into the capillary tube, and slide the tube along the fiber so that it covers the region to be inscribed. Now put on protective goggles and gently mount the fiber on the moving stage, which holds the phase mask.Angle the flat side of the capillary tube towards the phase mask. To protect the phase mask, use small pieces of foil to separate it from the capillary. Once positioned, the fiber should be within the masked interference pattern.Now align a 244 nanometer laser so that the beam is perpendicular to the flat surface of the phase mask. Before writing, make sure that the fiber gets at least 90 milliwatts of laser power. Use a beam splitter to separate out about one percent of the power and measure it.Now grate the fiber. Expose four centimeters to the UV interference pattern by moving the fiber and phase mask together at 0.25 millimeters per minute with respect to the incoming beam. Once completed, remove the capillary tube from the fiber.Then anneal the grating at 110 degrees Celcius for 20 hours to stabilize the wavelength response. Using a fiber cleaver, cleave both ends of the fiber. Set the fiber diameter intention to ensure a flat surface.Then illuminate one end of the fiber using a tunable laser with a central wavelength that is approximately matched to the Bragg wavelength. Connect a CCD camera to a PC with control software to display and record the fiber output. Image the fiber output with the CCD camera using a microscope objective lens with 50 times magnification in front of the camera to ensure that all cores cover multiple CCD pixels.Using software, select a circular region of pixels corresponding to each core. Click on the centers of cores and enter their diameters in units of pixels in the length or diameter field. Record the pixel values for the selected regions and sum all the pixels covering a given core to quantify the total throughput at that wavelength.Next connect the tunable laser to a computer to automate the data collection. In the software, enter a wavelength five nanometers below the Bragg wavelength in the Start Wavelength field. Then set the wavelength increment to 0.01 nanometers in the Scan Step field, and set the delay between the steps to at least 300 milliseconds so that the laser is stable at each wavelength.Now enter a wavelength five naometers above the Bragg wavelength in the End Wavelength field. Then scan three times and take an average value. Click the Automatic Scan button to set the laser to the defined parameters and perform the scan.Plot the transmitted power versus wavelength for each core to generate a set of spectra. Then compare the spectra of all cores to confirm whether they have the same suppression characteristics. Check that the central wavelength, depth, and bandwidth of each grating match.Without a capillary, transmission characteristics were assessed for a seven core fiber exposed using the standard methods. The individual core spectra are represented by different colors. There was minimal overlap between the suppressed wavelengths.The same characteristics were measured using an identical fiber inside a capillary tube with an inner diameter of 140 microns. In this multi-core fiber, Bragg ratings are much better overlapped. The single misaligned core was located at the center of the fiber, which had a Bragg wavelength 100 picometers shorter than the others.If only the outer cores are included in the calculation, a suppression greater than 36 decibels is possible. After watching this video, you should have a good understanding of how to modify the procedure for writing single mode fiber Bragg gratings for multi-core fibers. Once the capillaries are fabricated, they can be reused for each new grating.Following the method, we can produce larger size capillaries to much larger size fibers with several number cores. This will help us to understand why the inner cores behave differently, and indeed, to compensate or correct for this effect.

writing-bragg-gratings-in-multicore-fibers

Research

JoVE Journal

Engineering

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.

تصنيع وتوصيف المختلين بوليمر ألياف البصرية لعرضية أندرسون توطين الضوء

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

Writing and Low-Temperature Characterization of Oxide Nanostructures

Oxide nanoelectronics is a rapidly growing field which seeks to develop novel materials with multifunctional behavior at nanoscale dimensions. Oxide interfaces exhibit a wide range of properties that can be controlled include conduction, piezoelectric behavior, ferromagnetism, superconductivity and nonlinear optical properties. Recently, methods for controlling these properties at extreme nanoscale dimensions have been discovered and developed. Here are described explicit step-by-step procedures for creating LaAlO3/SrTiO3 nanostructures using a reversible conductive atomic force microscopy technique. The processing steps for creating electrical contacts to the LaAlO3/SrTiO3 interface are first described. Conductive nanostructures are created by applying voltages to a conductive atomic force microscope tip and locally switching the LaAlO3/SrTiO3 interface to a conductive state. A versatile nanolithography toolkit has been developed expressly for the purpose of controlling the atomic force microscope (AFM) tip path and voltage. Then, these nanostructures are placed in a cryostat and transport measurements are performed. The procedures described here should be useful to others wishing to conduct research in oxide nanoelectronics.

Oxide nanostructures provide new opportunities for science and technology. The interfacial conductivity between LaAlO3 and SrTiO3 can be controlled with near-atomic precision using a conductive atomic force microscopy technique. The protocol for creating and measuring conductive nanostructures at LaAlO3/SrTiO3 interfaces is demonstrated.

الكتابة وانخفاض درجة الحرارة توصيف أكسيد النانو

Oxide nanoelectronics is a rapidly growing field which seeks to develop novel materials with multifunctional behavior at nanoscale dimensions.  Oxide ...

Prescribed 3-D Direct Writing of Suspended Micron/Sub-micron Scale Fiber Structures via a Robotic Dispensing System

A 3-axis dispensing system is utilized to control the initiating and terminating fiber positions and trajectory via the dispensing software. The polymer fiber length and orientation is defined by the spatial positioning of the dispensing system 3-axis stages. The fiber diameter is defined by the prescribed dispense time of the dispensing system valve, the feed rate (the speed at which the stage traverses from an initiating to a terminating position), the gauge diameter of the dispensing tip, the viscosity and surface tension of the polymer solution, and the programmed drawing length. The stage feed rate affects the polymer solution&#8217;s evaporation rate and capillary breakup of the filaments. The dispensing system consists of a pneumatic valve controller, a droplet-dispensing valve and a dispensing tip. Characterization of the direct write process to determine the optimum combination of factors leads to repeatedly acquiring the desired range of fiber diameters. The advantage of this robotic dispensing system is the ease of obtaining a precise range of micron/sub-micron fibers onto a desired, programmed location via automated process control. Here, the discussed self-assembled micron/sub-micron scale 3D structures have been employed to fabricate suspended structures to create micron/sub-micron fluidic devices and bioengineered scaffolds.

Here, we present a protocol to fabricate freely-suspended, micron/sub-micron scale polymer fibers and &#8220;web-like&#8221; structures generated via automated direct writing procedure by means of a 3-axis dispensing system.

المنصوص عليها 3-D المباشر الكتابة من معلق ميكرون / ميكرون الفرعي الهياكل مقياس الألياف عن طريق نظام التركيب الروبوتية

A 3-axis dispensing system is utilized to control the initiating and terminating fiber positions and trajectory via the dispensing software. The polymer ...

Fabrication of High Contrast Gratings for the Spectrum Splitting Dispersive Element in a Concentrated Photovoltaic System

High contrast gratings are designed and fabricated and its application is proposed in a parallel spectrum splitting dispersive element that can improve the solar conversion efficiency of a concentrated photovoltaic system. The proposed system will also lower the solar cell cost in the concentrated photovoltaic system by replacing the expensive tandem solar cells with the cost-effective single junction solar cells. The structures and the parameters of high contrast gratings for the dispersive elements were numerically optimized. The large-area fabrication of high contrast gratings was experimentally demonstrated using nanoimprint lithography and dry etching. The quality of grating material and the performance of the fabricated device were both experimentally characterized. By analyzing the measurement results, the possible side effects from the fabrication processes are discussed and several methods that have the potential to improve the fabrication processes are proposed, which can help to increase the optical efficiency of the fabricated devices.

The fabrication of high contrast gratings as the parallel spectrum splitting dispersive element in a concentrated photovoltaic system is demonstrated. Fabrication processes including nanoimprint lithography, TiO2 sputtering and reactive ion etching are described. Reflectance measurement results are used to characterize the optical performance.

تصنيع حواجز شبكية عالية التباين لتقسيم الطيف المتشتتة عنصر في نظام الضوئية المركزة

High contrast gratings are designed and fabricated and its application is proposed in a parallel spectrum splitting dispersive element that can improve ...

Detection and Recovery of Palladium, Gold and Cobalt Metals from the Urban Mine Using Novel Sensors/Adsorbents Designated with Nanoscale Wagon-wheel-shaped Pores

Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in industrialized countries. Here, the development of optical mesosensors/adsorbents (MSAs) for efficient recognition and selective recovery of Pd(II), Au(III), and Co(II) from urban mine was achieved. A simple, general method for preparing MSAs based on using high-order mesoporous monolithic scaffolds was described. Hierarchical cubic Ia3d wagon-wheel-shaped MSAs were fabricated by anchoring chelating agents (colorants) into three-dimensional pores and micrometric particle surfaces of the mesoporous monolithic scaffolds. Findings show, for the first time, evidence of controlled optical recognition of Pd(II), Au(III), and Co(II) ions and a highly selective system for recovery of Pd(II) ions (up to ~95%) in ores and industrial wastes. Furthermore, the controlled assessment processes described herein involve evaluation of intrinsic properties (e.g., visual signal change, long-term stability, adsorption efficiency, extraordinary sensitivity, selectivity, and reusability); thus, expensive, sophisticated instruments are not required. Results show evidence that MSAs will attract worldwide attention as a promising technological means of recovering and recycling palladium, gold and cobalt metals.

Because of the importance and extensive use of palladium, gold and cobalt metals in high-technology equipment, their recovery and recycling constitute an important industrial challenge. The metal recovery system described herein is a simple, low-cost means for the effective detection, removal, and recovery of these metals from the urban mine.

كشف واستعادة البلاديوم والذهب والكوبالت المعادن من منجم الحضري عن طريق مجسات رواية / الممتزات مخصصة للمع النانو المسامات على شكل عجلة عربة

Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in ...

Recombination Dynamics in Thin-film Photovoltaic Materials via Time-resolved Microwave Conductivity

A method for investigating recombination dynamics of photo-induced charge carriers in thin film semiconductors, specifically in photovoltaic materials such as organo-lead halide perovskites is presented. The perovskite film thickness and absorption coefficient are initially characterized by profilometry and UV-VIS absorption spectroscopy. Calibration of both laser power and cavity sensitivity is described in detail. A protocol for performing Flash-photolysis Time Resolved Microwave Conductivity (TRMC) experiments, a non-contact method of determining the conductivity of a material, is presented. A process for identifying the real and imaginary components of the complex conductivity by performing TRMC as a function of microwave frequency is given. Charge carrier dynamics are determined under different excitation regimes (including both power and wavelength). Techniques for distinguishing between direct and trap-mediated decay processes are presented and discussed. Results are modelled and interpreted with reference to a general kinetic model of photoinduced charge carriers in a semiconductor. The techniques described are applicable to a wide range of optoelectronic materials, including organic and inorganic photovoltaic materials, nanoparticles, and conducting/semiconducting thin films.

A Time Resolved Microwave Conductivity technique for investigating direct and trap-mediated recombination dynamics and determining carrier mobilities of thin film semiconductors is presented here.

إعادة التركيب حيوية في الأغشية الرقيقة المواد الضوئية عن طريق وحلها الوقت ميكروويف التوصيل

A method for investigating recombination dynamics of photo-induced charge carriers in thin film semiconductors, specifically in photovoltaic materials ...

Experimental Implementation of a New Composite Fabrication Method: Exposing Bare Fibers on the Composite Surface by the Soft Layer Method

The bipolar plate is a key component in proton exchange membrane fuel cells (PEMFCs) and vanadium redox flow batteries (VRFBs). It is a multi-functional component that should have high electrical conductivity, high mechanical properties, and high productivity.
In this regard, a carbon fiber/epoxy resin composite can be an ideal material to replace the conventional graphite bipolar plate, which often leads to the catastrophic failure of the entire system because of its inherent brittleness. Though the carbon/epoxy composite has high mechanical properties and is easy to manufacture, the electrical conductivity in the through-thickness direction is poor because of the resin-rich layer that forms on its surface. Therefore, an expanded graphite coating was adopted to solve the electrical conductivity issue. However, the expanded graphite coating not only increases the manufacturing costs but also has poor mechanical properties.
In this study, a method to expose fibers on the composite surface is demonstrated. There are currently many methods that can expose fibers by surface treatment after the fabrication of the composite. This new method, however, does not require surface treatment because the fibers are exposed during the manufacture of the composite. By exposing bare carbon fibers on the surface, the electrical conductivity and mechanical strength of the composite are increased drastically.

A protocol to expose bare fibers on the composite surface by eliminating resin rich area is presented. The fibers are exposed during fabrication of the composites, not by the post surface treatment. The exposed carbon composites exhibit high electrical conductivity in the through-thickness direction and high mechanical property.

التنفيذ التجريبي لأسلوب تصنيع مركب جديد: تعريض الألياف العارية على سطح مركب بواسطة الأسلوب طبقة لينة

The bipolar plate is a key component in proton exchange membrane fuel cells (PEMFCs) and vanadium redox flow batteries (VRFBs). It is a multi-functional ...

Fabrication of Ultra-thin Color Films with Highly Absorbing Media Using Oblique Angle Deposition

Ultra-thin film structures have been studied extensively for use as optical coatings, but performance and fabrication challenges remain.&#160; We present an advanced method for fabricating ultra-thin color films with improved characteristics. The proposed process addresses several fabrication issues, including large area processing. Specifically, the protocol describes a process for fabricating ultra-thin color films using an electron beam evaporator for oblique angle deposition of germanium (Ge) and gold (Au) on silicon (Si) substrates.&#160; Film porosity produced by the oblique angle deposition induces color changes in the ultra-thin film. The degree of color change depends on factors such as deposition angle and film thickness. Fabricated samples of the ultra-thin color films showed improved color tunability and color purity. In addition, the measured reflectance of the fabricated samples was converted into chromatic values and analyzed in terms of color. Our ultra-thin film fabricating method is expected to be used for various ultra-thin film applications such as flexible color electrodes, thin film solar cells, and optical filters. Also, the process developed here for analyzing the color of the fabricated samples is broadly useful for studying various color structures.

We present a detailed method for fabricating ultra-thin color films with improved characteristics for optical coatings. The oblique angle deposition technique using an electron beam evaporator allows improved color tunability and purity. Fabricated films of Ge and Au on Si substrates were analyzed by reflectance measurements and color information conversion.

تصنيع الأفلام اللون رقيقة جداً مع الغاية استيعاب وسائل الإعلام استخدام الترسيب زاوية مائلة

Ultra-thin film structures have been studied extensively for use as optical coatings, but performance and fabrication challenges remain.&#160; We present ...

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

We demonstrate the use of two nuclear-based analytical methods that can follow the modifications of microstructural arrangement of iron-based metallic glasses (MGs). Despite their amorphous nature, the identification of hyperfine interactions unveils faint structural modifications. For this purpose, we have employed two techniques that utilize nuclear resonance among nuclear levels of a stable 57Fe isotope, namely M&#246;ssbauer spectrometry and nuclear forward scattering (NFS) of synchrotron radiation. The effects of heat treatment upon (Fe2.85Co1)77Mo8Cu1B14 MG are discussed using the results of ex situ and in situ experiments, respectively. As both methods are sensitive to hyperfine interactions, information on structural arrangement as well as on magnetic microstructure is readily available. M&#246;ssbauer spectrometry performed ex situ describes how the structural arrangement and magnetic microstructure appears at room temperature after the annealing under certain conditions (temperature, time), and thus this technique inspects steady states. On the other hand, NFS data are recorded in situ during dynamically changing temperature and NFS examines transient states. The use of both techniques provides complementary information. In general, they can be applied to any suitable system in which it is important to know its steady state but also transient states.

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Here, we present a protocol to describe ex situ and in situ investigations of structural transformations in metallic glasses. We employed nuclear-based analytical methods which inspect hyperfine interactions. We demonstrate the applicability of M&#246;ssbauer spectrometry and nuclear forward scattering of synchrotron radiation during temperature-driven experiments.

أساليب الموقع السابقين والتحقيق في عين المكان للتحولات الهيكلية: حالة بلورة نظارات معدنية

We demonstrate the use of two nuclear-based analytical methods that can follow the modifications of microstructural arrangement of iron-based metallic ...

A Random-displacement Measurement by Combining a Magnetic Scale and Two Fiber Bragg Gratings

Long-distance displacement measurements using optical fibers have always been a challenge in both basic research and industrial production. We developed and characterized a temperature-independent fiber Bragg grating (FBG)-based random-displacement sensor that adopts a magnetic scale as a novel transferring mechanism. By detecting shifts of two FBG center wavelengths, a full-range measurement can be obtained with a magnetic scale. For identification of the clockwise and counterclockwise rotation direction of the motor (in fact, the direction of movement of the object to be tested), there is a sinusoidal relationship between the displacement and the center wavelength shift of the FBG; as the anticlockwise rotation alternates, the center wavelength shift of the second FBG detector shows a leading phase difference of around 90&#176; (+90&#176;). As the clockwise rotation alternates, the center wavelength shift of the second FBG displays a lagging phase difference of around 90&#176; (-90&#176;). At the same time, the two FBG-based sensors are temperature independent. If there is some need for a remote monitor without any electromagnetic interference, this striking approach makes them a useful tool for determining the random displacement. This methodology is appropriate for industrial production. As the structure of the whole system is relatively simple, this displacement sensor can be used in commercial production. In addition to it being a displacement sensor, it can be used to measure other parameters, such as velocity and acceleration.

A protocol to create a full-range linear displacement sensor, combining two packaged fiber Bragg grating detectors with a magnetic scale, is presented.

قياس الازاحه العشوائية عن طريق الجمع بين مقياس مغناطيسي واثنين من ألياف براج الحواجز الشبكية

Long-distance displacement measurements using optical fibers have always been a challenge in both basic research and industrial production. We developed ...