Transmission Studies of a Long Single-Mode Fiber-Measurements and Considerations for Bandwidth Optimization

Abstract
Loss and bandwidth spectra were measured in the longest length of single-mode MCVD fiber drawn to date. The 21.7-km-long fiber guide has a 0.5 percent index difference between its 7-μm-diameter core and cladding. Chromatic dispersion effects resulted in a minimum dispersion at a wavelength near 1.35 μm. At 1.30 μm, the fiber loss and bandwidth were measured at 1 dB/km and 21 GHz km (source linewidth = 4 nm), respectively. Potential system performance was estimated from calculations of dispersion power penalties and chromatic-dispersion-limited repeater spacings for 274- and 548-Mb/s data transmission rates. A new numerical parametric study was used to show how the bandwidth of a fiber can be optimized by properly choosing its core diameter and core-to-cladding index difference.