Abstract

Wavelength-division multiplexing techniques are gaining acceptance for both point-to-point links and broadcast networks. Spectral slicing of a broadband source such as an LED (light emitting diode) or SLD (superluminescent diode) has been useful in providing wavelength-distinct sources for multiplexing¹ especially with amplifiers to increase source power.² The noise analysis is identical to the standard one for direct detection of an amplified signal except that there is an additional signal-signal beat term, often termed excess beat noise,³ which limits the signal-to-noise ratio (SNR) even if there is adequate power from sufficient amplifier gain. As the per-channel optical bandwidth decreases, the noise spectral density increases relative to the signal. At some point, further spectral slicing results in a signal with inherently unusable SNR. This work estimates the number of usable channels for both point-to-point links and broadcast wavelength-division multiaccess networks.

© 1992 Optical Society of America