Pulse dispersion properties of fibers with various material constituents

Intermodal dispersion properties are compared for high silica fibers with borosilicate (B2O3-SiO2) and germania borosilicate (GeO2-B2O3-SiO2) graded-index profiles. Pulse transmission measurements were systematically correlated with profile shapes so that new fibers could be fabricated with closer-to-optimal profile gradients at a wavelength of 907.5 nanometers. Germania borosilicate fibers with power law profile exponents (α ≈ 2.03) lowered intermodal dispersion 50 times from the result expected for comparable step-index fibers with N.A. ≈ 0.19. By contrast, borosilicate fibers with α ≈ 1.78 caused a 100-fold pulse width reduction in fibers with N.A. ≈ 0.14, corresponding to a 2σ = 0.13 ns/km pulse-broadening rate.