Back to descriptions of my articles on telecommunications - especially Hybrid Fibre Coax and other broadband systems.
Robin Whittle - First Principles Consulting 29 March 1998
(Slight update to www.techguide.com URL on 17 November 1998.)
Please email me at rw@firstpr.com.au if you would like to suggest any new sites to add to this, or any corrections. In particular, if you know of any sites which are actively being maintained to cover WDM in general, then please let me know, because I am not actively searching for sites to keep this one up-to-date. Alta Vista Advanced had 2,500 hits on "wavelength division multiplexing", most of them for documents less than a year old. The links below are far from a comprehensive survey of the field.
A hard-disk failure claimed the bookmark file with all the sites
I found
when I was researching the article.
For the latest updates in reverse date order, click
here!
http://www.idot.aol.com/mld/production/yiaz1310.html
Canadian company Cambrian Systems http://www.cambriansys.com/ specialises in WDM and photonic switching for LANs and WANs.
Fujitsu http://www.fujitsu.co.jp/hypertext/news/1997/Jan/cable.html announces that it has been awarded the USD$84 million contract for the SEA-ME-WE 3 Cable System - section 3, of 20 Gbps initially, linking Perth, Indonesia and Singapore. Fujitsu also got the contract to build the 40 Gbps China - Japan link. Both systems are planned to be completed in January 1999.
Uniphase Corporation manufactures laser and optical products,
including
Lithium
Niobate optical modulators for 2.5 and 10 Gbps: http://www.uniphase.com/UTP/epd_prod.htm
Monash University Associate Professor Jim Breen, at http://www.dgs.monash.edu.au/~jwb/subjects/dgs6910/ provides some excellent reference material on "Fibre Optics in communications, including photonic switching", including material on fibre manufacture and laser diodes. His site also contains material on telecommunications from the historical technologies, to the very latest
OKI has a glossary of fibre and laser terminology: http://www.okisemi.com/public/nf/LaserGlossary.html
The Information Superhighway Provides an On-Ramp for the
Underwater
Industry An interesting and detailed article by Howie Doyle in
UnderWater
Magazine, on the laying of submarine cables. http://www.diveweb.com/uw/uwarch/uw-su97.02.htm
There are at least two research teams fabricating infra-red laser
diodes
which are infinitely tunable (over a certain range) by application of
an
electrical voltage - which creates an electrostatic field, which moves
a mirror, which changes the resonant wavelength of the lasing
cavity.
Stanford researcher Fred Sugihwo http://www-snow.stanford.edu/~fred/
is on one of the teams researching Micromachined Tunable
Vertical-Cavity
Surface-Emitting Lasers
(Mi-T-VCSELs). See diagrams, electron microscope
images
and performance graphs here
and here.
Hai-Sheng
Wang at Cornell is working in the same field, but there does not seem
to
much on the Net about this project, except this.
Jocelyn Nee has photomicrographs of Surface-Micromachined
Diffraction
Gratings: http://ilpsoft.eecs.berkeley.edu:9636/~ilpsoft/98abstracts/jnee.1.html
This includes a picture of a planar silicon diffraction grating hinged
on
a silicon substrate so its angle of incidence to the light can be
altered
(in some way that is not clear to me) electrically.
This is not complete yet. I have more searching to do! Please check back in early April.
Two articles from the SubOptic 97" conference in San Francisco in
late
1997 - a four yearly conference on submarine cable systems.
Reliable
sources have told me that SubOptic '97 conference proceedings are
available
from David R Sprawls, Deputy Director of Tyco
Submarine Systems Ltd (formerly AT&T SSI) on fax +1 973 326
2609.
Either paper (bound) or CD format are available.
Fiber-Based Optical Components for Submarine Systems A.
Wada, K, Shima, H Sasaki, R Mtsumoto, N. Tanaka, F. Suzuki and R.
Yamauchi.
Fujikura Ltd. Proceedings of the Sub Optic Conference in San
Francisco.
(See
note above.) Pages 688 to 690. Discussion of finer points of
couplers
and Fibre Bragg Gratings, such as polarisation and temperature
stability.
Fiber Bragg Gratings for Dispersion Compensation in Transmission:
Theoretical Model and Design Criteria for Nearly Ideal Pulse
Recompression
Natalia M. Litchenitser, Benjamin J. Eggleton and David B. Patterson.
Journal
of Lightwave Technology, Vol. 15, No 8, August 1997 Pages 1303 to
1313. Deep material on designing FBGs which compensate for the
differing
propagation speeds of differing wavelengths in the hundred or so
kilometres
of fibre which precedes it. "Apodised" is another term for what
is
called "windowing" in Digital Signal Processing - it is a way of
shaping
the overall envelope of the impulse response of the filter to achieve
the
best tradeoff between pass-band performance and the response at other
frequencies
which the designer wishes to ignore.
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