<?xml version="1.0" encoding="ISO-8859-1"?><article 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">
<front>
<journal-meta>
<journal-id>0035-001X</journal-id>
<journal-title><![CDATA[Revista mexicana de física]]></journal-title>
<abbrev-journal-title><![CDATA[Rev. mex. fis.]]></abbrev-journal-title>
<issn>0035-001X</issn>
<publisher>
<publisher-name><![CDATA[Sociedad Mexicana de Física]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0035-001X2006000200005</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Guided-wave modes in graded-index optical fibers by two-point quasi-rational approximants]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Castro]]></surname>
<given-names><![CDATA[E.]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Puerta]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Cereceda]]></surname>
<given-names><![CDATA[C.]]></given-names>
</name>
</contrib>
</contrib-group>
<aff id="A01">
<institution><![CDATA[,Universidad Simón Bolívar Departamento de Física ]]></institution>
<addr-line><![CDATA[Caracas ]]></addr-line>
<country>Venezuela</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>04</month>
<year>2006</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>04</month>
<year>2006</year>
</pub-date>
<volume>52</volume>
<numero>2</numero>
<fpage>120</fpage>
<lpage>128</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S0035-001X2006000200005&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S0035-001X2006000200005&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S0035-001X2006000200005&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[Approximated analytic solutions for wave propagation in graded-index optical fiber have been found in the case of a parabolic profile. Approximants with high accuracy are presented that are much better than those found by other authors. A two-point quasi-rational method and two-point Pade approximants are used in this work. The approximants are explicitly determined for the azimuthal eigenvalues l = 0,1,2 and the mth mode numbers m = 0,1, 2, 3.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[En el presente trabajo, se obtuvieron soluciones analíticas aproximadas para la propagación de ondas en fibras ópticas con indice gradual en el caso de perfil parabólico. Los aproximantes obtenidos resultaron ser mas precisos que aquellas aproximaciones halladas previamente por otros autores. En este trabajo se usaron los aproximantes cuasi-racionales a dos puntos y los aproximantes de Padé. Se determinaron explícitamente los determinantes para los autovalores azimutales l = 0,1, 2 y los modos m = 0,1, 2,3.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[Two-point quasi-rational approximants]]></kwd>
<kwd lng="en"><![CDATA[graded-index fibres]]></kwd>
<kwd lng="en"><![CDATA[waveguide propagation]]></kwd>
<kwd lng="en"><![CDATA[eigenmode analysis]]></kwd>
<kwd lng="es"><![CDATA[Aproximantes cuasi-racionales a dos puntos]]></kwd>
<kwd lng="es"><![CDATA[fibras opticas de indice graduado]]></kwd>
<kwd lng="es"><![CDATA[propagación en guías de ondas]]></kwd>
<kwd lng="es"><![CDATA[analisis de los modos normales]]></kwd>
</kwd-group>
</article-meta>
</front><body><![CDATA[ <p align="justify"><font face="verdana" size="4">Investigaci&oacute;n</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="center"><font face="verdana" size="4"><b>Guided&#150;wave modes in graded&#150;index optical fibers by two&#150;point quasi&#150;rational approximants</b></font></p>     <p align="center"><font face="verdana" size="2">&nbsp;</font></p>     <p align="center"><font face="verdana" size="2"><b>E. Castro*, P. Mart&iacute;n, J. Puerta, and C. Cereceda</b></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><i>Departamento de F&iacute;sica, Universidad Sim&oacute;n Bol&iacute;var, </i><i>Apartado 89000, Caracas 1080A, Venezuela,</i></font></p>     <p align="justify"><font face="verdana" size="2"><i>*e&#150;mail: <a href="mailto:ecastro@usb.ve">ecastro@usb.ve</a></i></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2">Recibido el 8 de marzo de 2005    ]]></body>
<body><![CDATA[<br> Aceptado el 7 de febrero de 2006</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>Abstract</b></font></p>     <p align="justify"><font face="verdana" size="2">Approximated analytic solutions for wave propagation in graded&#150;index optical fiber have been found in the case of a parabolic profile. Approximants with high accuracy are presented that are much better than those found by other authors. A two&#150;point quasi&#150;rational method and two&#150;point Pade approximants are used in this work. The approximants are explicitly determined for the azimuthal eigenvalues <i>l</i> = 0,1,2 and the mth mode numbers <i>m </i>= 0,1, 2, 3.</font></p>     <p align="justify"><font face="verdana" size="2"><b>Keywords: </b>Two&#150;point quasi&#150;rational approximants; graded&#150;index fibres; waveguide propagation and eigenmode analysis.</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>Resumen</b></font></p>     <p align="justify"><font face="verdana" size="2">En el presente trabajo, se obtuvieron soluciones anal&iacute;ticas aproximadas para la propagaci&oacute;n de ondas en fibras &oacute;pticas con indice gradual en el caso de perfil parab&oacute;lico. Los aproximantes obtenidos resultaron ser mas precisos que aquellas aproximaciones halladas previamente por otros autores. En este trabajo se usaron los aproximantes cuasi&#150;racionales a dos puntos y los aproximantes de Pad&eacute;. Se determinaron expl&iacute;citamente los determinantes para los autovalores azimutales <i>l</i> = 0,1, 2 y los modos <i>m </i>= 0,1, 2,3.</font></p>     <p align="justify"><font face="verdana" size="2"><b>Descriptores: </b>Aproximantes cuasi&#150;racionales a dos puntos; fibras opticas de indice graduado; propagaci&oacute;n en gu&iacute;as de ondas y analisis de los modos normales.</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     ]]></body>
<body><![CDATA[<p align="justify"><font face="verdana" size="2">PACS: 02.30 Mv,42.81.Qb,42.81.Ht</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><a href="/pdf/rmf/v52n2/v52n2a5.pdf" target="_blank">DESCARGAR ART&Iacute;CULO EN FORMATO PDF</a></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>Acknowledgments</b></font></p>     <p align="justify"><font face="verdana" size="2">We would like to thank the referee for several suggestions which improved our first manuscript.</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>References</b></font></p>     <!-- ref --><p align="justify"><font face="verdana" size="2">1. P.K. Cheo, <i>Fiber Optics and Optoelectronics </i>(Prentice Hall Series In Solid Physical Electronics, Second Edition, 1990) Ch. 4.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317431&pid=S0035-001X200600020000500001&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">2. M. Young, <i>Optics and Lasers:   Including Fibers and Optical Waveguides </i>(Springer&#150;Verlag, Berlin Heidelberg, Fourth Revised Edition, 1993) Ch. 10.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317432&pid=S0035-001X200600020000500002&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">3. C.C. <i>Davis, Lasers and Electro&#150;Optics, Fundamentals and Engineering </i>(Cambridge University Press, 1996) Ch. 17.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317433&pid=S0035-001X200600020000500003&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">4. W. Streifer and C.N. Kurtz, <i>J. Opt. Soc. Am. </i><b>57</b> (1967) 779.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317434&pid=S0035-001X200600020000500004&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">5. S. Kawakami and Jun&#150;Ichi Nishizawa, <i>IEEE Trans. Microwave Theory Tech. </i><b>MIT&#150;16 </b>(1968) 814.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317435&pid=S0035-001X200600020000500005&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">6. E.G. Jhonson, J. Stack and C. Koehler, <i>J. Lightwave technol. </i><b>19</b> (2001) 753.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317436&pid=S0035-001X200600020000500006&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">7. F.C. Mc Neillie, J. Thomson, and I.S. Ruddock, <i>Eur. J. Phys. </i><b>25</b> (2004) 479.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317437&pid=S0035-001X200600020000500007&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">8. J.W. Rose and S.S. Mitra, <i>Optics Letter </i><b>6</b> (1981) 446.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317438&pid=S0035-001X200600020000500008&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">9. A.H. Hartog and M.J. Adams, <i>Opt. Quant. Elec. </i><b>9</b> (1977) 223.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317439&pid=S0035-001X200600020000500009&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">10. G.A. Jr. Baker and P.R. Graves&#150;Morris, <i>Pade Approximants, Part I: Basic Theory </i>(Encyclopedia of Mathematics and its Applications Vol 14) (Cambridge:  Cambridge University Press, 1981).</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317440&pid=S0035-001X200600020000500010&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">11. P. Mart&iacute;n , G. Donoso and J. Zamudio, <i>J. Math. Phys. </i><b>21</b> (1980) 280.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317441&pid=S0035-001X200600020000500011&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">12. E. Chalbaud and P. Mart&iacute;n, <i>J. Math. Phys. </i><b>25</b> (1984) 1268.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317442&pid=S0035-001X200600020000500012&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">13. E. Chalbaud and P. Mart&iacute;n, <i>J. Math. Phys. </i><b>27</b> (1986) 699.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317443&pid=S0035-001X200600020000500013&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">14. P. Mart&iacute;n and L. A. Guerrero, <i>J. Math. Phys. </i><b>26</b> (1985) 705.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317444&pid=S0035-001X200600020000500014&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">15. K. Visentin and P. Mart&iacute;n, <i>J. Math. Phys. </i><b>28</b> (1987) 330.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317445&pid=S0035-001X200600020000500015&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">16. A.L. Guerrero and P. Mart&iacute;n, <i>J. Comput. Phys. </i><b>77</b> (1988) 276.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317446&pid=S0035-001X200600020000500016&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">17. P. Mart&iacute;n and A.L. Guerrero, <i>J. Comput. Phys. </i><b>85</b> (1989) 487.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317447&pid=S0035-001X200600020000500017&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">18. P. Mart&iacute;n, and G. Baker, <i>J. Math. Phys. </i><b>32</b> (1991) 1470.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317448&pid=S0035-001X200600020000500018&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">19. E. Chalbaud and P. Mart&iacute;n, <i>J. Math. Phys. </i><b>33</b> (1992) 2483.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317449&pid=S0035-001X200600020000500019&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">20. P. Mart&iacute;n, R. Perez, and L.A. Guerrero, <i>J. Comput. Phys. </i><b>99</b> (1992) 337.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317450&pid=S0035-001X200600020000500020&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">21. L. Brualla and P. Mart&iacute;n, <i>J. Phys. A: Math. Gen. </i><b>34</b> (2001) 9153.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317451&pid=S0035-001X200600020000500021&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">22. P. Mart&iacute;n and J. Puerta, <i>Eur. J. Phys. </i><b>12</b> (1991) 1992.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317452&pid=S0035-001X200600020000500022&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">23. P. Mart&iacute;n, J.J. Rodriguez&#150;Nu&ntilde;ez, and J.L. M&aacute;rquez, <i>Phys. Rev. B </i><b>45</b> (1992) 8359.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317453&pid=S0035-001X200600020000500023&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">24. E. Castro and P. Mart&iacute;n, <i>J. Phys. A: Math. Gen. </i><b>33</b> (2000) 5321.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317454&pid=S0035-001X200600020000500024&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">25. C.L. Ladera and P. Mart&iacute;n, <i>J. Comput. Phys. </i><b>73</b> (1987) 481.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317455&pid=S0035-001X200600020000500025&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">26. L.C. Ladera and P. Mart&iacute;n, <i>J. Phys. A: Math. Gen. </i><b>34</b> (2001) 4571.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317456&pid=S0035-001X200600020000500026&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">27. S. Nakamura, <i>Applied Numerical Method with Software </i>(Englewood Cliffs, N J: Prentice Hall, 1992) Ch. 9.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8317457&pid=S0035-001X200600020000500027&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --> ]]></body><back>
<ref-list>
<ref id="B1">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Cheo]]></surname>
<given-names><![CDATA[P.K.]]></given-names>
</name>
</person-group>
<source><![CDATA[Fiber Optics and Optoelectronics]]></source>
<year>1990</year>
<edition>Second Edition</edition>
<publisher-name><![CDATA[Prentice Hall]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B2">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Young]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
</person-group>
<source><![CDATA[Optics and Lasers: Including Fibers and Optical Waveguides]]></source>
<year>1993</year>
<edition>Fourth</edition>
<publisher-loc><![CDATA[BerlinHeidelberg ]]></publisher-loc>
<publisher-name><![CDATA[Springer-Verlag]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B3">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Davis]]></surname>
<given-names><![CDATA[C.C.]]></given-names>
</name>
</person-group>
<source><![CDATA[Lasers and Electro-Optics: Fundamentals and Engineering]]></source>
<year>1996</year>
<publisher-name><![CDATA[Cambridge University Press]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B4">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Streifer]]></surname>
<given-names><![CDATA[W.]]></given-names>
</name>
<name>
<surname><![CDATA[Kurtz]]></surname>
<given-names><![CDATA[C.N.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Opt. Soc. Am.]]></source>
<year>1967</year>
<numero>57</numero>
<issue>57</issue>
<page-range>779</page-range></nlm-citation>
</ref>
<ref id="B5">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Kawakami]]></surname>
<given-names><![CDATA[S.]]></given-names>
</name>
<name>
<surname><![CDATA[Nishizawa]]></surname>
<given-names><![CDATA[Jun-Ichi]]></given-names>
</name>
</person-group>
<source><![CDATA[IEEE Trans. Microwave Theory Tech.]]></source>
<year>1968</year>
<page-range>814</page-range></nlm-citation>
</ref>
<ref id="B6">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Jhonson]]></surname>
<given-names><![CDATA[E.G.]]></given-names>
</name>
<name>
<surname><![CDATA[Stack]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
<name>
<surname><![CDATA[Koehler]]></surname>
<given-names><![CDATA[C.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Lightwave technol.]]></source>
<year>2001</year>
<numero>19</numero>
<issue>19</issue>
<page-range>753</page-range></nlm-citation>
</ref>
<ref id="B7">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Mc Neillie]]></surname>
<given-names><![CDATA[F.C.]]></given-names>
</name>
<name>
<surname><![CDATA[Thomson]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
<name>
<surname><![CDATA[Ruddock]]></surname>
<given-names><![CDATA[I.S.]]></given-names>
</name>
</person-group>
<source><![CDATA[Eur. J. Phys.]]></source>
<year>2004</year>
<numero>25</numero>
<issue>25</issue>
<page-range>479</page-range></nlm-citation>
</ref>
<ref id="B8">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Rose]]></surname>
<given-names><![CDATA[J.W.]]></given-names>
</name>
<name>
<surname><![CDATA[Mitra]]></surname>
<given-names><![CDATA[S.S.]]></given-names>
</name>
</person-group>
<source><![CDATA[Optics Letter]]></source>
<year>1981</year>
<numero>6</numero>
<issue>6</issue>
<page-range>446</page-range></nlm-citation>
</ref>
<ref id="B9">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Hartog]]></surname>
<given-names><![CDATA[A.H.]]></given-names>
</name>
<name>
<surname><![CDATA[Adams]]></surname>
<given-names><![CDATA[M.J.]]></given-names>
</name>
</person-group>
<source><![CDATA[Opt. Quant. Elec.]]></source>
<year>1977</year>
<numero>9</numero>
<issue>9</issue>
<page-range>223</page-range></nlm-citation>
</ref>
<ref id="B10">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Baker]]></surname>
<given-names><![CDATA[G.A. Jr.]]></given-names>
</name>
<name>
<surname><![CDATA[Graves-Morris]]></surname>
<given-names><![CDATA[P.R.]]></given-names>
</name>
</person-group>
<article-title xml:lang="en"><![CDATA[Pade Approximants: Part I: Basic Theory]]></article-title>
<source><![CDATA[Encyclopedia of Mathematics and its Applications]]></source>
<year>1981</year>
<volume>14</volume>
<publisher-loc><![CDATA[Cambridge ]]></publisher-loc>
<publisher-name><![CDATA[Cambridge University Press]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B11">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
<name>
<surname><![CDATA[Donoso]]></surname>
<given-names><![CDATA[G.]]></given-names>
</name>
<name>
<surname><![CDATA[Zamudio]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Math. Phys.]]></source>
<year>1980</year>
<numero>21</numero>
<issue>21</issue>
<page-range>280</page-range></nlm-citation>
</ref>
<ref id="B12">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Chalbaud]]></surname>
<given-names><![CDATA[E.]]></given-names>
</name>
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Math. Phys.]]></source>
<year>1984</year>
<numero>25</numero>
<issue>25</issue>
<page-range>1268</page-range></nlm-citation>
</ref>
<ref id="B13">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Chalbaud]]></surname>
<given-names><![CDATA[E.]]></given-names>
</name>
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Math. Phys.]]></source>
<year>1986</year>
<numero>27</numero>
<issue>27</issue>
<page-range>699</page-range></nlm-citation>
</ref>
<ref id="B14">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
<name>
<surname><![CDATA[Guerrero]]></surname>
<given-names><![CDATA[L. A.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Math. Phys.]]></source>
<year>1985</year>
<numero>26</numero>
<issue>26</issue>
<page-range>705</page-range></nlm-citation>
</ref>
<ref id="B15">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Visentin]]></surname>
<given-names><![CDATA[K.]]></given-names>
</name>
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Math. Phys.]]></source>
<year>1987</year>
<numero>28</numero>
<issue>28</issue>
<page-range>330</page-range></nlm-citation>
</ref>
<ref id="B16">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Guerrero]]></surname>
<given-names><![CDATA[A.L.]]></given-names>
</name>
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Comput. Phys.]]></source>
<year>1988</year>
<numero>77</numero>
<issue>77</issue>
<page-range>276</page-range></nlm-citation>
</ref>
<ref id="B17">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
<name>
<surname><![CDATA[Guerrero]]></surname>
<given-names><![CDATA[A.L.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Comput. Phys.]]></source>
<year>1989</year>
<numero>85</numero>
<issue>85</issue>
<page-range>487</page-range></nlm-citation>
</ref>
<ref id="B18">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
<name>
<surname><![CDATA[Baker]]></surname>
<given-names><![CDATA[G.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Math. Phys.]]></source>
<year>1991</year>
<numero>32</numero>
<issue>32</issue>
<page-range>1470</page-range></nlm-citation>
</ref>
<ref id="B19">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Chalbaud]]></surname>
<given-names><![CDATA[E.]]></given-names>
</name>
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Math. Phys.]]></source>
<year>1992</year>
<numero>33</numero>
<issue>33</issue>
<page-range>2483</page-range></nlm-citation>
</ref>
<ref id="B20">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
<name>
<surname><![CDATA[Perez]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
<name>
<surname><![CDATA[Guerrero]]></surname>
<given-names><![CDATA[L.A.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Comput. Phys.]]></source>
<year>1992</year>
<numero>99</numero>
<issue>99</issue>
<page-range>337</page-range></nlm-citation>
</ref>
<ref id="B21">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Brualla]]></surname>
<given-names><![CDATA[L.]]></given-names>
</name>
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Phys. A: Math. Gen.]]></source>
<year>2001</year>
<numero>34</numero>
<issue>34</issue>
<page-range>9153</page-range></nlm-citation>
</ref>
<ref id="B22">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
<name>
<surname><![CDATA[Puerta]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
</person-group>
<source><![CDATA[Eur. J. Phys.]]></source>
<year>1991</year>
<numero>12</numero>
<issue>12</issue>
<page-range>1992</page-range></nlm-citation>
</ref>
<ref id="B23">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
<name>
<surname><![CDATA[Rodriguez-Nuñez]]></surname>
<given-names><![CDATA[J.J.]]></given-names>
</name>
<name>
<surname><![CDATA[Márquez]]></surname>
<given-names><![CDATA[J.L.]]></given-names>
</name>
</person-group>
<source><![CDATA[Phys. Rev. B]]></source>
<year>1992</year>
<numero>45</numero>
<issue>45</issue>
<page-range>8359</page-range></nlm-citation>
</ref>
<ref id="B24">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Castro]]></surname>
<given-names><![CDATA[E.]]></given-names>
</name>
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Phys. A: Math. Gen.]]></source>
<year>2000</year>
<numero>33</numero>
<issue>33</issue>
<page-range>5321</page-range></nlm-citation>
</ref>
<ref id="B25">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ladera]]></surname>
<given-names><![CDATA[C.L.]]></given-names>
</name>
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Comput. Phys.]]></source>
<year>1987</year>
<numero>73</numero>
<issue>73</issue>
<page-range>481</page-range></nlm-citation>
</ref>
<ref id="B26">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ladera]]></surname>
<given-names><![CDATA[L.C.]]></given-names>
</name>
<name>
<surname><![CDATA[Martín]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<source><![CDATA[J. Phys. A: Math. Gen.]]></source>
<year>2001</year>
<numero>34</numero>
<issue>34</issue>
<page-range>4571</page-range></nlm-citation>
</ref>
<ref id="B27">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Nakamura]]></surname>
<given-names><![CDATA[S.]]></given-names>
</name>
</person-group>
<source><![CDATA[Applied Numerical Method with Software]]></source>
<year>1992</year>
<publisher-loc><![CDATA[Englewood Cliffs^eN J N J]]></publisher-loc>
<publisher-name><![CDATA[Prentice Hall]]></publisher-name>
</nlm-citation>
</ref>
</ref-list>
</back>
</article>
