EVALUATION OF MATERIAL DISPERSION USING A NANOSECOND OPTICAL PULSE RADIATOR

To study the material dispersion effects on graded-index fibers, a method for measuring the material dispersion in optical glass fibers has been developed. Nanosecond pulses in the 0.5-1.7-μm region are generated by a nanosecond optical pulse radiator and grating monochromator. These pulses are injected into a GeO2-P2O5-doped silica graded-index fiber. Relative time delay changes between different wavelengths are used to determine material dispersion, core glass refractive index, material group index, and optimum profile parameter of the graded-index fiber. From the measured data, the optimum profile parameter on the GeO2-P2O5-doped silica graded-index fiber could be estimated to be 1.88 at 1.27 μm of the material dispersion free wavelength region and 1.82 at 1.55 μm of the lowest-loss wavelength region in silica-based optical fiber wave guides. © 1979 Optical Society of America.