Low-loss, high-aperture germanium–fluorine-codoped single-mode fibers

10.1007/s10789-008-3012-4

“…A large number of optical fiber devices (e.g., Raman fiber lasers and amplifiers, parametric amplifiers, fiber dispersion compensators, supercontinuum sources, and nonlinear switches) take advantage of nonlinear effects that take place during light propagation along singlemode optical fibers (SMFs) [1][2][3][4][5][6][7]. The efficiency of nonlinear devices is determined by the light power density in the fiber core, which is known to rise with decreasing mode field size.…”

“…Since the drawing temperature has a strong effect on the optical loss in SMFs [1,3,5], all of the fibers were drawn at the same, lowest possible temperature, 1860°C, which prevented disruption due to the strong tension and made it possible to minimize the optical loss. To study the effect of the shape of the RIP across SMFs, several series of preforms with graded (smooth) and step index profiles were prepared by MCVD.…”

“…Optical loss spectra of fibers drawn at the same temperature with (1) unetched,(2,3) etched, and (4) fully removed central index dips. Optical loss spectra of fibers drawn at the same temperature with (1) unetched,(2,3) etched, and (4) fully removed central index dips.…”