ISRJ_FORMA new - Indian Streams Research Journal

Vol 6 Issue 7 August 2016
ISSN No : 2230-7850
ORIGINAL ARTICLE
International Multidisciplinary
Research Journal
Indian Streams
Research Journal
Executive Editor
Ashok Yakkaldevi
Editor-in-Chief
H.N.Jagtap
Welcome to ISRJ
RNI MAHMUL/2011/38595
ISSN No.2230-7850
Indian Streams Research Journal is a multidisciplinary research journal, published monthly in English,
Hindi & Marathi Language. All research papers submitted to the journal will be double - blind peer reviewed
referred by members of the editorial board.Readers will include investigator in universities, research institutes
government and industry with research interest in the general subjects.
Regional Editor
Dr. T. Manichander
Mr. Dikonda Govardhan Krushanahari
Professor and Researcher ,
Rayat shikshan sanstha’s, Rajarshi Chhatrapati Shahu College, Kolhapur.
International Advisory Board
Kamani Perera
Regional Center For Strategic Studies, Sri
Lanka
Mohammad Hailat
Dept. of Mathematical Sciences,
University of South Carolina Aiken
Janaki Sinnasamy
Librarian, University of Malaya
Abdullah Sabbagh
Engineering Studies, Sydney
Romona Mihaila
Spiru Haret University, Romania
Ecaterina Patrascu
Spiru Haret University, Bucharest
Delia Serbescu
Spiru Haret University, Bucharest,
Romania
Loredana Bosca
Spiru Haret University, Romania
Anurag Misra
DBS College, Kanpur
Titus PopPhD, Partium Christian
University, Oradea,Romania
Fabricio Moraes de Almeida
Federal University of Rondonia, Brazil
George - Calin SERITAN
Faculty of Philosophy and Socio-Political
Sciences Al. I. Cuza University, Iasi
Hasan Baktir
English Language and Literature
Department, Kayseri
Ghayoor Abbas Chotana
Dept of Chemistry, Lahore University of
Management Sciences[PK]
Anna Maria Constantinovici
AL. I. Cuza University, Romania
Ilie Pintea,
Spiru Haret University, Romania
Xiaohua Yang
PhD, USA
......More
Editorial Board
Iresh Swami
Pratap Vyamktrao Naikwade
ASP College Devrukh,Ratnagiri,MS India Ex - VC. Solapur University, Solapur
R. R. Patil
Head Geology Department Solapur
University,Solapur
Rama Bhosale
Prin. and Jt. Director Higher Education,
Panvel
Salve R. N.
Department of Sociology, Shivaji
University,Kolhapur
Govind P. Shinde
Bharati Vidyapeeth School of Distance
Education Center, Navi Mumbai
Chakane Sanjay Dnyaneshwar
Arts, Science & Commerce College,
Indapur, Pune
Awadhesh Kumar Shirotriya
Secretary,Play India Play,Meerut(U.P.)
N.S. Dhaygude
Ex. Prin. Dayanand College, Solapur
Narendra Kadu
Jt. Director Higher Education, Pune
K. M. Bhandarkar
Praful Patel College of Education, Gondia
Sonal Singh
Vikram University, Ujjain
Rajendra Shendge
Director, B.C.U.D. Solapur University,
Solapur
R. R. Yalikar
Director Managment Institute, Solapur
Umesh Rajderkar
Head Humanities & Social Science
YCMOU,Nashik
S. R. Pandya
Head Education Dept. Mumbai University,
Mumbai
Alka Darshan Shrivastava
G. P. Patankar
S. D. M. Degree College, Honavar, Karnataka Shaskiya Snatkottar Mahavidyalaya, Dhar
Maj. S. Bakhtiar Choudhary
Director,Hyderabad AP India.
Rahul Shriram Sudke
Devi Ahilya Vishwavidyalaya, Indore
S.Parvathi Devi
Ph.D.-University of Allahabad
S.KANNAN
Annamalai University,TN
Sonal Singh,
Vikram University, Ujjain
Satish Kumar Kalhotra
Maulana Azad National Urdu University
Address:-Ashok Yakkaldevi 258/34, Raviwar Peth, Solapur - 413 005 Maharashtra, India
Cell : 9595 359 435, Ph No: 02172372010 Email: ayisrj@yahoo.in Website: www.isrj.org
ISSN: 2230-7850
Impact Factor : 4.1625(UIF)
Volume - 6 | Issue - 7 | August - 2016
Indian Streams Research Journal
FIBRE-OPTIC COMMUNICATION SYSTEM
Alpana Kumari
Research Scholar , L.N.M.U Darbhanga .
ABSTRACT
n fibre-optic communication, a single-mode optical
fibre (SMF) is an optical fibre designed to carry light only
directly down the fibre - the transverse mode. Modes
are the possible solutions of the Helmholtz equation for
waves, which is obtained by combining Maxwell's
equations and the boundary conditions. These modes
define the way the wave travels through space, i.e. how the
wave is distributed in space.
I
KEYWORDS :fibre-optic communication, combining
Maxwell's equations , boundary conditions.
INTRODUCTION
Waves can have the same mode but have different
frequencies. This is the case in single-mode fibres, where
we can have waves with different frequencies, but of the
same mode, which means that they are distributed in space
in the same way, and that gives us a single ray of light.
Although the ray travels parallel to the length of the fibre, it
is often called transverse mode since its electromagnetic
vibrations occur perpendicular (transverse) to the length of
the fibre. The 2009 Nobel Prize in Physics was awarded to
Charles K. Kao for his theoretical work on the single-mode
optical fibre.[1-4]
Like multi-mode optical fibres, single mode fibres
do exhibit modal dispersion resulting from multiple spatial
modes but with narrower modal dispersion. Single mode
fibres are therefore better at retaining the fidelity of each
light pulse over longer distances than multi-mode fibres.
For these reasons, single-mode fibres can have a higher
bandwidth than multi-mode fibres. Equipment for single
mode fibre is more expensive than equipment for multimode optical fibre, but the single mode fibre itself is usually
cheaper in bulk.
SINGLE MODE OPTICAL FIBRE
A typical single mode optical
fibre has a core diameter between 8 and
10.5 µm and a cladding diameter of 125
µm. There are a number of special types
of single-mode optical fibre which have
been chemically or physically altered to
give special properties, such as
dispersion-shifted fibre and nonzero
dispersion-shifted fibre. Data rates are
limited by polarization mode dispersion
and chromatic dispersion. As of 2005,
data rates of up to 10 gigabits per
second were possible at distances of
over 80 km (50 mi) with commercially
available transceivers (Xenpak). By
using optical amplifiers and dispersioncompensating devices, state-of-the-art
DWDM optical systems can span
thousands of kilometers at 10 Gbit/s,
and several hundred kilometers at 40
Gbit/s.
The lowest-order bounds mode
is ascertained for the wavelength of
Available online at www.lsrj.in
1
Volume - 6 | Issue - 7 | August - 2016
FIBRE-OPTIC COMMUNICATION SYSTEM
interest by solving Maxwell's equations for the boundary conditions imposed by the fibre, which are
determined by the core diameter and the refractive indices of the core and cladding. The solution of
Maxwell's equations for the lowest order bound mode will permit a pair of orthogonally polarized fields
in the fibre, and this is the usual case in a communication fibre.
In step-index guides, single-mode operation occurs when the normalized frequency, V, is less
than or equal to 2.405. Forpower-law profiles, single-mode operation occurs for a normalized
frequency, V, less than approximately
,
where g is the profile parameter.
In practice, the orthogonal polarizations may not be associated with degenerate modes.
Os1 and OS2 are standard single-mode optical fibre used with wavelengths 1310 nm and 1550 nm (size
9/125 µm) with a maximum attenuation of 1 dB/km (OS1) and .4 dB/km (OS2). OS1 is defined in ISO/IEC
11801, and OS2 is defined in ISO/IEC 24702.
Fig.1.1 Single Mode Fibre Optic Cable
Single Mode fibre optic cable has a small diametral core that allows only one mode of light to
propagate. Because of this, the number of light reflections created as the light passes through the core
decreases, lowering attenuation and creating the ability for the signal to travel faster, further. This
application is typically used in long distance, higher bandwidth runs by Telcos, CATV companies, and
Colleges and Universities.
Left: Single Mode fibre is usually 9/125 in construction. This means that the core to cladding
diameter ratio is 9 microns to 125 microns.
Fig.1.2 Multimode Fibre Optic Cable
Available online at www.lsrj.in
2
FIBRE-OPTIC COMMUNICATION SYSTEM
Volume - 6 | Issue - 7 | August - 2016
Multimode fibre optic cable has a large diametral core that allows multiple modes of light to
propagate. Because of this, the number of light reflections created as the light passes through the core
increases, creating the ability for more data to pass through at a given time. Because of the high
dispersion and attenuation rate with this type of fibre, the quality of the signal is reduced over long
distances. This application is typically used for short distance, data and audio/video applications in
LANs. RF broadband signals, such as what cable companies commonly use, cannot be transmitted over
multimode fibre.
Above: Multimode fibre is usually 50/125 and 62.5/125 in construction. This means that the
core to cladding diameter ratio is 50 microns to 125 microns and 62.5 microns to 125 microns.[3-6]
STEP-INDEX MULTIMODE FIBRE
Due to its large core, some of the light rays that make up the digital pulse may travel a direct
route, whereas others zigzag as they bounce off the cladding. These alternate paths cause the different
groups of light rays, referred to as modes, to arrive separately at the receiving point. The pulse, an
aggregate of different modes, begins to spread out, losing its well-defined shape. The need to leave
spacing between pulses to prevent overlapping limits the amount of information that can be sent. This
type of fibre is best suited for transmission over short distances.
GRADED-INDEX MULTIMODE FIBRE
It Contains a core in which the refractive index diminishes gradually from the center axis out
toward the cladding. The higher refractive index at the centre makes the light rays moving down the
axis advance more slowly than those near the cladding. Due to the graded index, light in the core curves
helically rather than zigzag off the cladding, reducing its travel distance. The shortened path and the
higher speed allow light at the periphery to arrive at a receiver at about the same time as the slow but
straight rays in the core axis. The result: digital pulse suffers less dispersion. This type of fibre is best
suited for local-area networks.
The main difference between multi-mode and single-mode optical fibre is that the former has
much larger core diameter, typically 50–100 micrometers; much larger than the wavelength of the light
carried in it. Because of the large core and also the possibility of large numerical aperture, multi-mode
fibre has higher "light-gathering" capacity than single-mode fibre. In practical terms, the larger core
size simplifies connections and also allows the use of lower-cost electronics such as light-emitting
diodes (LEDs) and vertical-cavity surface-emitting lasers (VCSELs) which operate at the 850 nm and
1300 nm wavelength (single-mode fibres used in telecommunications operate at 1310 or 1550 nm and
require more expensive laser sources. Single mode fibres exist for nearly all visible wavelengths of
light). However, compared to single-mode fibres, the multi-mode fibre bandwidth–distance product
limit is lower. Because multi-mode fibre has a larger core-size than single-mode fibre, it supports more
than one propagation mode; hence it is limited by modal dispersion, while single mode is not.
The LED light sources sometimes used with multi-mode fibre produce a range of wavelengths
and these each propagate at different speeds. This chromatic dispersion is another limit to the useful
length for multi-mode fibre optic cable. In contrast, the lasers used to drive single-mode fibres produce
coherent light of a single wavelength. Due to the modal dispersion, multi-mode fibre has higher pulse
spreading rates than single mode fibre, limiting multi-mode fibre’s information transmission capacity.
REFERENCES
1 F. P. Kapron et al., 'Radiation losses in glass optical waveguides', Appl. Phys. Lett., vol. 17, no. 10, pp.
Available online at www.lsrj.in
3
FIBRE-OPTIC COMMUNICATION SYSTEM
Volume - 6 | Issue - 7 | August - 2016
423-425, 1970.
2.IEEE 802.3-2002, ‘Information Technology- Telecommunication & Information Exchange Between
Systems - Local and Metropolitan Area Networks – Specific Requirements, Part 3: Carrier Sense
Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications
2002’.
3.TIA/EIA-455-203 (2001), FOTP-203 - Launched Power Distribution Measurement Procedure for
Graded-Index Multimode Fibre Transmitters
4.TIA/EIA-455-54-B (2001), ‘FOTP-54 - Mode Scrambler Requirements for Overfilled Launching
Conditions to Multimode Fibres’
5.TIA/EIA-455-204 (2000), ‘ FOTP-204 - Measurement of Bandwidth on Multimode Fibre.
6 .J. B. Schlager et al., 'Measurements for Enhanced Bandwidth Performance Over 62.5 um Multimode
Fibre in Short-Wavelength Local Area Networks', IEEE J. Lightwave Technol., vol. 21, no. 5, pp. 12761285, 2003.
Available online at www.lsrj.in
4
Publish Research Article
International Level Multidisciplinary Research Journal
For All Subjects
Dear Sir/Mam,
We invite unpublished Research Paper,Summary of Research
Project,Theses,Books and Book Review for publication,you will be pleased to
know that our journals are
Associated and Indexed,India
¬
International Scientific Journal Consortium
¬
OPEN J-GATE
Associated and Indexed,USA
?
Google Scholar
?
EBSCO
?
DOAJ
?
Index Copernicus
?
Publication Index
?
Academic Journal Database
?
Contemporary Research Index
?
Academic Paper Databse
?
Digital Journals Database
?
Current Index to Scholarly Journals
?
Elite Scientific Journal Archive
?
Directory Of Academic Resources
?
Scholar Journal Index
?
Recent Science Index
?
Scientific Resources Database
?
Directory Of Research Journal Indexing
Indian Streams Research Journal
258/34 Raviwar Peth Solapur-413005,Maharashtra
Contact-9595359435
E-Mail-ayisrj@yahoo.in/ayisrj2011@gmail.com
Website : www.isrj.org
Download PDF
Similar pages