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<article article-type="research-article" dtd-version="1.3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:lang="ru"><front><journal-meta><journal-id journal-id-type="publisher-id">gyroscopy</journal-id><journal-title-group><journal-title xml:lang="ru">Гироскопия и навигация</journal-title><trans-title-group xml:lang="en"><trans-title>Giroskopiya i Navigatsiya</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">0869-7035</issn><issn pub-type="epub">2075-0927</issn><publisher><publisher-name>AO «Концерн «ЦНИИ «Электроприбор»</publisher-name></publisher></journal-meta><article-meta><article-id custom-type="elpub" pub-id-type="custom">gyroscopy-455</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>Статьи</subject></subj-group></article-categories><title-group><article-title>О пределах чувствительности оптических гироскопов на связанных резонаторах в зависимости от материальных потерь</article-title><trans-title-group xml:lang="en"><trans-title></trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Калантаров</surname><given-names>Д.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Калантаров Дмитрий, магистр наук, аспирант. </p></bio><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Сёрч</surname><given-names>К.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Сёрч Кристофер, кандидат наук, доцент. </p></bio><xref ref-type="aff" rid="aff-1"/></contrib></contrib-group><aff xml:lang="ru" id="aff-1"><institution>Технологический институт Стивенса (Хобокен)</institution><country>United States</country></aff><pub-date pub-type="collection"><year>2014</year></pub-date><pub-date pub-type="epub"><day>29</day><month>01</month><year>2026</year></pub-date><volume>22</volume><issue>3</issue><fpage>41</fpage><lpage>52</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Калантаров Д., Сёрч К., 2026</copyright-statement><copyright-year>2026</copyright-year><copyright-holder xml:lang="ru">Калантаров Д., Сёрч К.</copyright-holder><copyright-holder xml:lang="en">Калантаров Д., Сёрч К.</copyright-holder><license xml:lang="ru" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>Данная работа распространяется под лицензией Creative Commons Attribution 4.0.</license-p></license><license xml:lang="en" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>This work is licensed under a Creative Commons Attribution 4.0 License.</license-p></license></permissions><self-uri xlink:href="https://www.gyroscopy.ru/jour/article/view/455">https://www.gyroscopy.ru/jour/article/view/455</self-uri><abstract><p>В последние годы особый интерес вызывают оптические микрорезонаторы, используемые в перспективных недорогих микрооптических гироскопах с чувствительностью на навигационном уровне. В данной работе сравнивается чувствительность к вращению оптических гироскопов на связанных резонаторах (ОГСР-гироскопов) и таких же гироскопов с одним резонатором при различных геометрических ограничениях и параметрах приборов. Показано, что ОГСР-гироскопы обладают более высокой чувствительностью по сравнению с обычными однорезонаторными гироскопами при низких потерях на распространение. Проанализирована максимальная чувствительность для различных материалов (Hydex, оксинитрид кремния, кремний на изоляторе.</p><p>Статья по докладу на XXI Санкт-Петербургской международной конференции по интегрированным навигационным системам.</p></abstract><trans-abstract xml:lang="en"><p>In recent years there has been a growing interest in optical microresonators as viable low cost on chip micro-optical gyroscopes with navigation grade sensitivities. Here, we analyze and compare the rotational sensitivity of coupled resonator optical waveguide (CROW) gyroscopes to equivalent single resonator gyroscopes under various geometric constraints and device parameters. We show that the CROW gyros offer a sensitivity enhancement over conventional single resonator gyros at low propagation losses. However, the single ring resonator gyro is found to be more stable over a wider range of propagation losses as well as boasting greater sensitivities for larger propagation losses compared to a CROW of the same size. Furthermore, an analysis of the maximum achievable sensitivity for different material technologies (Hydex, silicon oxynitride, and SOI) is conducted. While all materials achieved tactical grade sensitivities, Hydex shows the greatest potential for CROW gyros because of the stability of its sensitivity over a wide range of device parameters.</p></trans-abstract><kwd-group xml:lang="en"><kwd>Gyroscopes</kwd><kwd>Sagnac effect</kwd><kwd>Integrated optics</kwd></kwd-group></article-meta></front><back><ref-list><title>References</title><ref id="cit1"><label>1</label><citation-alternatives><mixed-citation xml:lang="ru">Ciminelli, C., Dell'Olio, F., Campanella, C. E., and Armenise, M. N., Photonic technologies for angular velocity sensing, Adv. Opt. Photon. 2, 370-404 (2010).</mixed-citation><mixed-citation xml:lang="en">Ciminelli, C., Dell'Olio, F., Campanella, C. E., and Armenise, M. N., Photonic technologies for angular velocity sensing, Adv. Opt. Photon. 2, 370-404 (2010).</mixed-citation></citation-alternatives></ref><ref id="cit2"><label>2</label><citation-alternatives><mixed-citation xml:lang="ru">Passaro, V. de Tullio, C., Troia, B., Notte, M., Giannoccaro, G. and Leonardis, F., Recent Advances in Integrated Photonic Sensors, Sensors 12, 15558-15598 (2012).</mixed-citation><mixed-citation xml:lang="en">Passaro, V. de Tullio, C., Troia, B., Notte, M., Giannoccaro, G. and Leonardis, F., Recent Advances in Integrated Photonic Sensors, Sensors 12, 15558-15598 (2012).</mixed-citation></citation-alternatives></ref><ref id="cit3"><label>3</label><citation-alternatives><mixed-citation xml:lang="ru">Scheuer, J. and Yariv, A., Sagnac effect in coupled-resonator slow-light waveguide structures, Phys. Rev. Lett. 90, 053901 (2006).</mixed-citation><mixed-citation xml:lang="en">Scheuer, J. and Yariv, A., Sagnac effect in coupled-resonator slow-light waveguide structures, Phys. Rev. Lett. 90, 053901 (2006).</mixed-citation></citation-alternatives></ref><ref id="cit4"><label>4</label><citation-alternatives><mixed-citation xml:lang="ru">Terrel, M. A., Digonnet, M. J. F., and Fan,S., Performance limitation of a coupled resonant optical waveguide gyroscope, J. Lightwave Technol. 27, 47 (2009).</mixed-citation><mixed-citation xml:lang="en">Terrel, M. A., Digonnet, M. J. F., and Fan,S., Performance limitation of a coupled resonant optical waveguide gyroscope, J. Lightwave Technol. 27, 47 (2009).</mixed-citation></citation-alternatives></ref><ref id="cit5"><label>5</label><citation-alternatives><mixed-citation xml:lang="ru">Terrel, M., Digonnet, M. J. F., and Fan, S., Performance comparison of slow-light coupledresonator optical gyroscopes, Laser &amp; Photon. Rev. 3, 452-465 (2009).</mixed-citation><mixed-citation xml:lang="en">Terrel, M., Digonnet, M. J. F., and Fan, S., Performance comparison of slow-light coupledresonator optical gyroscopes, Laser &amp; Photon. Rev. 3, 452-465 (2009).</mixed-citation></citation-alternatives></ref><ref id="cit6"><label>6</label><citation-alternatives><mixed-citation xml:lang="ru">Kalantarov, D. and Search, C. P., Effect of input–output coupling on the sensitivity of coupled resonator optical waveguide gyroscopes, J. Opt. Soc. Am. B 30, 377-381 (2013).</mixed-citation><mixed-citation xml:lang="en">Kalantarov, D. and Search, C. P., Effect of input–output coupling on the sensitivity of coupled resonator optical waveguide gyroscopes, J. Opt. Soc. Am. B 30, 377-381 (2013).</mixed-citation></citation-alternatives></ref><ref id="cit7"><label>7</label><citation-alternatives><mixed-citation xml:lang="ru">Kalantarov, D. and Search, C. P., Effect of resonator losses on the sensitivity of coupled resonator optical waveguide gyroscopes, 39, 4, pp. 985-988 (2014).</mixed-citation><mixed-citation xml:lang="en">Kalantarov, D. and Search, C. P., Effect of resonator losses on the sensitivity of coupled resonator optical waveguide gyroscopes, 39, 4, pp. 985-988 (2014).</mixed-citation></citation-alternatives></ref><ref id="cit8"><label>8</label><citation-alternatives><mixed-citation xml:lang="ru">Toland, J. R. E., Kaston, Z. A., Sorrentino, C., and Search, C. P., Chirped area coupled resonator optical waveguide gyroscope, Opt. Lett. 36, 1221-1223 (2011).</mixed-citation><mixed-citation xml:lang="en">Toland, J. R. E., Kaston, Z. A., Sorrentino, C., and Search, C. P., Chirped area coupled resonator optical waveguide gyroscope, Opt. Lett. 36, 1221-1223 (2011).</mixed-citation></citation-alternatives></ref><ref id="cit9"><label>9</label><citation-alternatives><mixed-citation xml:lang="ru">Sorrentino, C., Toland, J., and Search, C. P., Ultra-sensitive chip scale Sagnac gyroscope based on periodically modulated coupling of a coupled resonator optical waveguide, Opt. Express 20, 354-363 (2012).</mixed-citation><mixed-citation xml:lang="en">Sorrentino, C., Toland, J., and Search, C. P., Ultra-sensitive chip scale Sagnac gyroscope based on periodically modulated coupling of a coupled resonator optical waveguide, Opt. Express 20, 354-363 (2012).</mixed-citation></citation-alternatives></ref><ref id="cit10"><label>10</label><citation-alternatives><mixed-citation xml:lang="ru">Steinberg, B. Z., Scheuer, J. and Boag, A., Rotation-induced superstructure in slow-light waveguides with mode degeneracy: optical gyroscopes with exponential sensitivity J. Opt. Soc. Am. B 24, 1216-1224 (2007).</mixed-citation><mixed-citation xml:lang="en">Steinberg, B. Z., Scheuer, J. and Boag, A., Rotation-induced superstructure in slow-light waveguides with mode degeneracy: optical gyroscopes with exponential sensitivity J. Opt. Soc. Am. B 24, 1216-1224 (2007).</mixed-citation></citation-alternatives></ref><ref id="cit11"><label>11</label><citation-alternatives><mixed-citation xml:lang="ru">Novitski, R., Steinberg, B. Z., and Scheuer, J., Losses in rotating degenerate cavities and a coupled-resonator optical-waveguide rotation sensor, Phys. Rev. A 85, 023813 (2012).</mixed-citation><mixed-citation xml:lang="en">Novitski, R., Steinberg, B. Z., and Scheuer, J., Losses in rotating degenerate cavities and a coupled-resonator optical-waveguide rotation sensor, Phys. Rev. A 85, 023813 (2012).</mixed-citation></citation-alternatives></ref><ref id="cit12"><label>12</label><citation-alternatives><mixed-citation xml:lang="ru">Scully, M. and Suhail Zubairy, M., Quantum Optics (Cambridge University Press, Cambridge, UK, 1997).</mixed-citation><mixed-citation xml:lang="en">Scully, M. and Suhail Zubairy, M., Quantum Optics (Cambridge University Press, Cambridge, UK, 1997).</mixed-citation></citation-alternatives></ref><ref id="cit13"><label>13</label><citation-alternatives><mixed-citation xml:lang="ru">Ruffin, P. B., Fiber optics gyroscope sensors in Fiber Optic Sensors, 2nd ed. edited by F. T. S. Yu, S. Yin, and P. B. Ruffin (CRC Press, 2008).</mixed-citation><mixed-citation xml:lang="en">Ruffin, P. B., Fiber optics gyroscope sensors in Fiber Optic Sensors, 2nd ed. edited by F. T. S. Yu, S. Yin, and P. B. Ruffin (CRC Press, 2008).</mixed-citation></citation-alternatives></ref><ref id="cit14"><label>14</label><citation-alternatives><mixed-citation xml:lang="ru">Poon, J. K. S., Scheuer, J., Mookherjea, S., Paloczi, G. T., Huang, Y., and Yariv, A., Matrix analysis of microring coupled-resonator optical waveguides, Opt. Express 12, 90-103 (2004).</mixed-citation><mixed-citation xml:lang="en">Poon, J. K. S., Scheuer, J., Mookherjea, S., Paloczi, G. T., Huang, Y., and Yariv, A., Matrix analysis of microring coupled-resonator optical waveguides, Opt. Express 12, 90-103 (2004).</mixed-citation></citation-alternatives></ref><ref id="cit15"><label>15</label><citation-alternatives><mixed-citation xml:lang="ru">Capmany, J., Munoz, P., Domenech, J. D., Muriel, M. A., Apodized coupled resonator waveguides, Opt. Express 15, 10196-10206 (2007).</mixed-citation><mixed-citation xml:lang="en">Capmany, J., Munoz, P., Domenech, J. D., Muriel, M. A., Apodized coupled resonator waveguides, Opt. Express 15, 10196-10206 (2007).</mixed-citation></citation-alternatives></ref><ref id="cit16"><label>16</label><citation-alternatives><mixed-citation xml:lang="ru">Poon, J. K. S., Scheuer, J., Xu, Y., and Yariv, A., Designing coupled-resonator optical waveguide delay lines, J. Opt. Soc. Am. B 21, 1665-1673 (2004).</mixed-citation><mixed-citation xml:lang="en">Poon, J. K. S., Scheuer, J., Xu, Y., and Yariv, A., Designing coupled-resonator optical waveguide delay lines, J. Opt. Soc. Am. B 21, 1665-1673 (2004).</mixed-citation></citation-alternatives></ref><ref id="cit17"><label>17</label><citation-alternatives><mixed-citation xml:lang="ru">Little, B. E., Chu, S. T., Haus, H. A., Foresi, J., and Laine, J. P., Microring resonator channel dropping filters, J. Lightwave Technology 15, 998-1005 (1997).</mixed-citation><mixed-citation xml:lang="en">Little, B. E., Chu, S. T., Haus, H. A., Foresi, J., and Laine, J. P., Microring resonator channel dropping filters, J. Lightwave Technology 15, 998-1005 (1997).</mixed-citation></citation-alternatives></ref><ref id="cit18"><label>18</label><citation-alternatives><mixed-citation xml:lang="ru">Hah, D. and Zhan, D. g, Analysis of resonant optical gyroscopes with two input/output waveguides, Opt. Express 18, 18200-18205 (2010).</mixed-citation><mixed-citation xml:lang="en">Hah, D. and Zhan, D. g, Analysis of resonant optical gyroscopes with two input/output waveguides, Opt. Express 18, 18200-18205 (2010).</mixed-citation></citation-alternatives></ref><ref id="cit19"><label>19</label><citation-alternatives><mixed-citation xml:lang="ru">Canciamilla, A., Torregiani, M., Ferrari, C., Morichetti, F., De La Rue, R. M., Samarelli, A., Sorel, M., and Melloni, A., Silicon coupled-ring resonator structures for slow light applications: potential, impairments and ultimate limits, J. Opt. 12, 104008 (2010).</mixed-citation><mixed-citation xml:lang="en">Canciamilla, A., Torregiani, M., Ferrari, C., Morichetti, F., De La Rue, R. M., Samarelli, A., Sorel, M., and Melloni, A., Silicon coupled-ring resonator structures for slow light applications: potential, impairments and ultimate limits, J. Opt. 12, 104008 (2010).</mixed-citation></citation-alternatives></ref><ref id="cit20"><label>20</label><citation-alternatives><mixed-citation xml:lang="ru">Guillen-Torres, M.A., Cretu, E., Jaeger, N.A.F., Chrostowski, L., Ring Resonator Optical Gyroscopes-Parameter Optimization and Robustness Analysis, Journal of Lightwave Technology 30(12), 1802-1817 (2012).</mixed-citation><mixed-citation xml:lang="en">Guillen-Torres, M.A., Cretu, E., Jaeger, N.A.F., Chrostowski, L., Ring Resonator Optical Gyroscopes-Parameter Optimization and Robustness Analysis, Journal of Lightwave Technology 30(12), 1802-1817 (2012).</mixed-citation></citation-alternatives></ref><ref id="cit21"><label>21</label><citation-alternatives><mixed-citation xml:lang="ru">Morichetti, F., Ferrari, C., Canciamilla, A., and Melloni, A., The first decade of coupled resonator optical waveguides: bringing slow light to applications, Laser &amp; Photon. Rev. 6, 74-96 (2012).</mixed-citation><mixed-citation xml:lang="en">Morichetti, F., Ferrari, C., Canciamilla, A., and Melloni, A., The first decade of coupled resonator optical waveguides: bringing slow light to applications, Laser &amp; Photon. Rev. 6, 74-96 (2012).</mixed-citation></citation-alternatives></ref><ref id="cit22"><label>22</label><citation-alternatives><mixed-citation xml:lang="ru">Morichetti, F., Melloni, A., Ferrari, C., and Martinelli, M., Error-free continuously-tunable delay at 10 Gbit/s in a reconfigurable on-chip delay-line, Opt. Express 16(12), 8395-8405 (2008).</mixed-citation><mixed-citation xml:lang="en">Morichetti, F., Melloni, A., Ferrari, C., and Martinelli, M., Error-free continuously-tunable delay at 10 Gbit/s in a reconfigurable on-chip delay-line, Opt. Express 16(12), 8395-8405 (2008).</mixed-citation></citation-alternatives></ref><ref id="cit23"><label>23</label><citation-alternatives><mixed-citation xml:lang="ru">Xia F., Sekaric L., and Vlasov Y., Ultracompact optical buffers on a silicon chip, Nature Photon. 1, 65-71(2007).</mixed-citation><mixed-citation xml:lang="en">Xia F., Sekaric L., and Vlasov Y., Ultracompact optical buffers on a silicon chip, Nature Photon. 1, 65-71(2007).</mixed-citation></citation-alternatives></ref><ref id="cit24"><label>24</label><citation-alternatives><mixed-citation xml:lang="ru">Gnan M., Thorns S., Macintyre D.S., De La Rue R.M., Sorel M., Fabrication of low-loss photonic wires in silicon-on-insulator using hydrogen silsesquioxane electron-beam resist, Electronics Letters 44 (2) 115-116 (2008).</mixed-citation><mixed-citation xml:lang="en">Gnan M., Thorns S., Macintyre D.S., De La Rue R.M., Sorel M., Fabrication of low-loss photonic wires in silicon-on-insulator using hydrogen silsesquioxane electron-beam resist, Electronics Letters 44 (2) 115-116 (2008).</mixed-citation></citation-alternatives></ref><ref id="cit25"><label>25</label><citation-alternatives><mixed-citation xml:lang="ru">Morichetti F., Melloni A., Breda A., Canciamilla A., Ferrari C., and Martinelli M., A reconfigurable architecture for continuously variable optical slow-wave delay lines, Opt. Express 15, 17273-17282 (2007)</mixed-citation><mixed-citation xml:lang="en">Morichetti F., Melloni A., Breda A., Canciamilla A., Ferrari C., and Martinelli M., A reconfigurable architecture for continuously variable optical slow-wave delay lines, Opt. Express 15, 17273-17282 (2007)</mixed-citation></citation-alternatives></ref><ref id="cit26"><label>26</label><citation-alternatives><mixed-citation xml:lang="ru">Melloni, A., Costa, R., Monguzzi, P., and Martinelli, M., Ring-resonator filters in silicon oxynitride technology for dense wavelength-division multiplexing systems, Opt. Lett. 28, 1567-1569 (2003)</mixed-citation><mixed-citation xml:lang="en">Melloni, A., Costa, R., Monguzzi, P., and Martinelli, M., Ring-resonator filters in silicon oxynitride technology for dense wavelength-division multiplexing systems, Opt. Lett. 28, 1567-1569 (2003)</mixed-citation></citation-alternatives></ref><ref id="cit27"><label>27</label><citation-alternatives><mixed-citation xml:lang="ru">Duchesne, D.; Ferrera, M.; Razzari, L.; Morandotti, R.; Little, B. E.; Chu, S. T. &amp; Moss, D. J. Efficient self-phase modulation in low loss, high index doped silica glass integrated waveguides, Opt. Express, 17, 3, 1865-1870 (2009).</mixed-citation><mixed-citation xml:lang="en">Duchesne, D.; Ferrera, M.; Razzari, L.; Morandotti, R.; Little, B. E.; Chu, S. T. &amp; Moss, D. J. Efficient self-phase modulation in low loss, high index doped silica glass integrated waveguides, Opt. Express, 17, 3, 1865-1870 (2009).</mixed-citation></citation-alternatives></ref><ref id="cit28"><label>28</label><citation-alternatives><mixed-citation xml:lang="ru">Ferrera, M., Razzari, L., Duchesne, D., Morandotti, R., Yang, Z., Liscidini, M., Sipe, J. E., Chu, S., Little, B. E. and Moss, D. J.. Low power continuous-wave nonlinear optics in doped silica glass integrated waveguide structures, Nature Photonics Vol. 2, 12, 737 (2008).</mixed-citation><mixed-citation xml:lang="en">Ferrera, M., Razzari, L., Duchesne, D., Morandotti, R., Yang, Z., Liscidini, M., Sipe, J. E., Chu, S., Little, B. E. and Moss, D. J.. Low power continuous-wave nonlinear optics in doped silica glass integrated waveguide structures, Nature Photonics Vol. 2, 12, 737 (2008).</mixed-citation></citation-alternatives></ref><ref id="cit29"><label>29</label><citation-alternatives><mixed-citation xml:lang="ru">Little, B.E., Chu, S. T. Absil, P. P., Hryniewicz, J. V., Johnson, F. G., Seiferth, F., Gill, D., Van, V., King, O., and Trakalo, M., Very high order microring resonator filters for WDM applications, IEEE Photonics Technology Letters, vol. 16, no. 10, pp. 2263-2265, (2004) 30. Cooper, M. L., Gupta, G., Schneider, M. A., Green, W. M. J., Assefa, S., Xia, F., Vlasov, Y. A., and Mookherjea S., Statistics of light transport in 235-ring silicon coupled-resonator optical waveguides, Optics Express Vol. 18, pp. 26505-26516 (2010).</mixed-citation><mixed-citation xml:lang="en">Little, B.E., Chu, S. T. Absil, P. P., Hryniewicz, J. V., Johnson, F. G., Seiferth, F., Gill, D., Van, V., King, O., and Trakalo, M., Very high order microring resonator filters for WDM applications, IEEE Photonics Technology Letters, vol. 16, no. 10, pp. 2263-2265, (2004) 30. Cooper, M. L., Gupta, G., Schneider, M. A., Green, W. M. J., Assefa, S., Xia, F., Vlasov, Y. A., and Mookherjea S., Statistics of light transport in 235-ring silicon coupled-resonator optical waveguides, Optics Express Vol. 18, pp. 26505-26516 (2010).</mixed-citation></citation-alternatives></ref><ref id="cit30"><label>30</label><citation-alternatives><mixed-citation xml:lang="ru">Melloni, A., Canciamilla, A., Ferrari, C., Morichetti, F., Faolain, L. O., Krauss, T. F., De La Rue, R., Samarelli, A., and Sorel, M., Tunable Delay Lines in Silicon Photonics: Coupled Resonators and Photonic Crystals, a Comparison, Photonics Journal, IEEE 2, 181-194 (2010).</mixed-citation><mixed-citation xml:lang="en">Melloni, A., Canciamilla, A., Ferrari, C., Morichetti, F., Faolain, L. O., Krauss, T. F., De La Rue, R., Samarelli, A., and Sorel, M., Tunable Delay Lines in Silicon Photonics: Coupled Resonators and Photonic Crystals, a Comparison, Photonics Journal, IEEE 2, 181-194 (2010).</mixed-citation></citation-alternatives></ref></ref-list><fn-group><fn fn-type="conflict"><p>The authors declare that there are no conflicts of interest present.</p></fn></fn-group></back></article>
