A simple method for study of effect of Kerr nonlinearity on effective core area, index of refraction and fractional modal power through the core of monomode graded index fibre

2020 ◽  
Vol 12 (1/2) ◽  
pp. 136
Author(s):  
Mithun Maity ◽  
Anup Kumar Maiti ◽  
Himadri Mandal ◽  
Sankar Gangopadhyay
2014 ◽  
Vol 35 (4) ◽  
Author(s):  
Angshuman Majumdar ◽  
Satabdi Das ◽  
Sankar Gangopadhyay

AbstractBased on the simple power series formulation of fundamental mode developed by Chebyshev formalism in the low V region, we prescribe analytical expression for effective core area of graded index fiber. Taking step and parabolic index fibers as examples, we estimate the effective core areas as well as effective refractive index for different normalized frequencies (V number) having low values. We also show that our estimations match excellently with the available exact results. The concerned predictions by our method require little computation. Thus, this simple but accurate formalism will be user friendly for the system engineers.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jayanta Aich ◽  
Angshuman Majumdar ◽  
Sankar Gangopadhyay

Abstract A new technique is presented for computing very useful propagation parameters like effective core area and effective index of refraction of mono-mode dispersion shifted and dispersion flattened fibers both in the presence and in the absence of Kerr nonlinearity. The technique involves application of accurate but simple expressions for modal fields developed by Chebyshev formalism. The study of the influence of Kerr nonlinearity on the aforementioned parameters, however, requires the application of the method of iteration. For the purpose of such investigation, in linear as well as nonlinear region, we take some typically used dispersion shifted and dispersion flattened fibers and we show that the results found by our simple formalism are in excellent agreement with those obtained by using complex finite element method. Further, the necessary evaluation by our simple method needs very less computations. Thus, our formalism generates ample opportunity for applications in many areas in the field of nonlinear optics.


1986 ◽  
Vol 23 (3) ◽  
pp. 197-210
Author(s):  
A. Owens

An undergraduate experiment, of approximately six hours duration, is presented, in which the refractive index profile of a graded index fibre is measured using the near-field scanning method. The numerical aperture is obtained from far-field measurements and the core and cladding diameters are measured directly using an optical bench microscope and stage micrometer.


Author(s):  
Sonny Tasidjawa ◽  
Stephanus V Mandagi ◽  
Ridwan Lasabuda

Bahoi village is located in West Likupang District of North Minahasa Regency. It is one of the villages that is included in the conservation network of North Sulawesi Province. A marine sanctuary has been established in this village in 2003 and it has been managed by local community, known as community-based marine sanctuary management, since then, this sanctuary has been in operation. As a small community-based marine protected area with lots of users, it requires an appropriate method to determine the Core Zone that allows an effective preservation of the marine biota. This is the driving factor of this study.  The purpose of this study is to examine the processes and output of determining the core zone of a Marine Sanctuary using a conventional method and Marxan Method. The conventional method is a simple method in determining a core zone such as using manta tow technique. While Marxan, it only requires input of data such as spatial and figures to generate information for determining the core zone. After comparing the processes of these two methods in the study site, it was found that Marxan method was more effective and more accurate with lower costs than the conventional one. In addition, the final decision of the core zone depended on the outcome of the village meetings when the conventional method was applied. This long process could be avoided when Marxan method was used. Therefore, it is highly recommended to use Marxan in determining core zones© Desa Bahoi terletak di Kecamatan Likupang Barat Kabupaten Minahasa Utara. Desa ini merupakan salah satu desa yang masuk dalam jejaringan kawasan konservasi di Provinsi Sulawesi Utara. Sebuah Daerah Perlindungan Laut telah didirikan di desa ini pada tahun 2003 dan dikelolah oleh masyarakat setempat, yang dikenal sebagai pengelolaan Daerah Perlindungan Laut Berbasis Masyarakat, sejak saat itu Daerah Perlindungan Laut ini telah beroperasi. Sebagai Daerah Perlindungan Laut Berbasis Masyarakat yang kecil namun memiliki banyak pengguna, diperlukan metode tepat yang akan menentukan Zona Inti yang memungkinkan pelestarian biota laut menjadi sangat efektif. Ini adalah faktor pendorong dari penelitian. Selanjutnya, tujuan dari penelitian ini adalah untuk mengkaji proses dan hasil penentuan zona inti Daerah Perlindungan Laut dengan menggunakan metode konvensional seperti survei manta tow dan marxan. Metode konvensional adalah metode sederhana dalam menentukan zona inti seperti teknik manta tow. Sedangkan marxan, hanya perlu memasukan data seperti spasial dan angka untuk menghasilkan informasi penentuan zona inti. Setelah membandingkan proses dari dua metode di lokasi penelitian, ditemukan bahwa metode marxan jauh lebih baik dari pada metode konvensional, karena lebih efektif, lebih akurat dengan biaya yang lebih rendah. Selain itu, keputusan akhir dari zona inti tergantung pada hasil rapat desa ketika metode konvensional diterapkan, proses panjang ini dapat dihindari jika metode marxan digunakan©


2011 ◽  
Vol 71-78 ◽  
pp. 1411-1420
Author(s):  
Cheng Zhang ◽  
Si Wei Wang

Nowadays, Underground space exploitation is one of the directions of the main focus in the construction of Hangzhou. This paper comprehensively introduces the schematic design of the underground space exploitation of Hangzhou east station, combined with the underground space development project of the core area in Hangzhou eastern new city zone. Firstly, the background of the surrounding area is discussed to illuminate the important status of the core area of eastern new city zone in Hangzhou’s future construction. Then, the holistic design concept and construction goal of the underground space exploitation of the core area are presented, and its functions and layout are clarified focusing on the railway construction and circumjacent exploitation project of Hangzhou east station. Lastly, the executive plan about the underground space exploitation of the core area of Hangzhou eastern new city zone is expatiated comprehensively.


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