This paper discusses how the damping at wavelength 1.55 µm depends on various factors for anisotropic single-mode lightguides with boron germanosilicate elliptical cladding. It is shown that the refractive index of this cladding in the preform has a substantial effect on the optical losses of the lightguides. The thickness of the cladding that isolates the core from the boron-containing glass of the elliptical cladding is optimized. The optical losses to Rayleigh scattering are reduced by doping the core with small additives of moisture. For a lightguide with a glass-fiber diameter of 125 µm in a two-layer polymeric coating, an optical loss level equal to 0.5 dB/km is achieved, with a polarization maintenance of 5×10<sup>-6</sup>m<sup>-1</sup>.
© 2012 OSA
Original Manuscript: November 18, 2011
Published: July 31, 2012
K. V. Dukel’skiĭ, S. V. Bureev, M. A. Bisyarin, I. K. Meshkovskiĭ, M. A. Eron’yan, A. V. Komarov, E. Yu. Utkin, E. I. Romashova, and M. M. Serkov, "Minimizing the optical losses in anisotropic single-mode lightguides with elliptical boron germanosilicate cladding," J. Opt. Technol. 79, 433-436 (2012)