Page 225 - Optical Communications Essentials

Wavelength Division Multiplexing

Wavelength Division Multiplexing 215

of 18 wavelengths defined within the range of 1270 to 1610nm (O- through L-
bands) spaced by 20nm with wavelength drift tolerances of 2nm.
Table 12.2 presents some typical performance parameters for 8-channel
DWDM and CWDM multiplexers based on thin-film-filter technology. Table 12.3
lists some performance characteristics of typical 40-channel arrayed waveguide
gratings. Table 12.4 gives typical performance values for commercially available
interleavers.
The implementation of DWDM using very closely spaced channels is not pos-
sible without having strict wavelength stability control in the transmitter. As
Sec. 12.3 describes, this is the function of commercially available wavelength
lockers.

Further Reading

1. G. E. Keiser, “A review of WDM technology and applications,” Optical Fiber Tech., vol. 5,
pp. 3–39, January 1999.
2. ITU-T Recommendation G.692, Optical Interfaces for Multichannel Systems with Optical
Amplifiers, October 1998.
3. J. Prieur, G. Pandraud, M. Colin, and B. Vida, “High-port-count interleavers provide network
design options,” WDM Solutions, vol. 4, pp. 27–32, September 2002.
4. J.-P. Laude, DWDM Fundamentals, Components, and Applications, Artech House, Boston, 2002.
5. W. T. Boord, T. L. Vanderwert, and R. DeSalvo, “Bulk diffraction gratings play increasing role in
optical networking,” Lightwave, vol. 18, pp. 172–178, March 2001.
6. A. Ashmead, “Electronically switchable Bragg gratings provide versatility,” Lightwave, vol. 18,
pp. 180–184, March 2001.
7. F. Chatain, “Fiber Bragg grating technology passes light to new passive components,” Lightwave,
vol. 18, pp. 186, 190–191, March 2001.
8. H. Shakouri, “Wavelength lockers make fixed and tunable lasers precise,” WDM Solutions, vol. 4,
pp. 23–32, January 2002.

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