Considerations for single-mode fiber systems

The intrinsic low-dispersion and low-attenuation properties of single-mode fibers between 1.3 and 1.6 μm make them attractive for use in high-capacity, long-haul digital systems. In this paper we discuss some fundamental performance limitations — such as attenuation, bandwidth, mode-partition noise, burst-type error, and receiver sensitivities — for systems with bit rates above 274 Mb/s. Also, we discuss the maximum capacity achievable by either using a single channel at the minimum-dispersion wavelength, or multiple wavelength-multiplexed channels with equal, but necessarily lower, bit rates. We conclude that the characteristics of present laser diodes limit repeater spacing to lengths far less than the potential capacity expected from single-mode fibers. For total capacity of bit rates less than 1 Gb/s, wavelength multiplexing is found to offer longer repeater spacings than single-wavelength systems.