Long Wavelength Glass Fiber System Considerations and Single Mode Waveguide Design.

System aspects of ultra low loss fluoride fibers, such as optical nonlinearities, dispersion characteristics, and source and detector capabilities, were analyzed to determine the ultimate performance limits. Repeater spacings of 3600 km at = 1 Gbit/sec may be possible. Waveguide propagation characteristics have been calculated for step and triangular refractive index profiles for three representative halide glasses between 2 and 10microns. Small relative index differences can be used to offset material dispersion. Microdeformation losses are calculated with a coupled mode and a spotsize theory. Very low microdeformation losses can be achieved with the small index differences. For long deformation correlation lengths it may be difficult to achieve very low losses at wavelength >= 3microns.