Measurement of the nonlinear index of silica-core and dispersion-shifted fibers

Abstract

We have accurately measured the nonlinear refractive index, n₂, of the glass found in silica-core and dispersion-shifted optical fibers. We find that at 1.319 µm the n₂ of silica-core and dispersion-shifted fibers is 2.36 × 10⁻¹⁶ and 2.52 × 10⁻¹⁶ cm²/W (±5%), respectively. We also estimate that the n₂ of germania is three times the n₂ of pure silica. Because the wavelength dependence of n₂ between 1.3 and 1.5 µm is known to be small, our measured values should also be valid at 1.55 µm.