Fundamental mode size and bend sensitivity of graded and step-index single-mode fibers with zero-dispersion near 1.55 µm

Abstract

Single-mode fibers, for near 1.55-μm operating system wavelength with triangular ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\alpha = 1</tex> ), parabolic ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\alpha = 2</tex> ), and step-index ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\alpha=\infty</tex> ) profiles were fabricated by the modified chemical vapor deposition (MCVD) technique. Optical transmission losses under zero-tension and with the basket weave under 10, 40, and 70 gm tensions were measured, respectively. Fundamental mode size was obtained as a function of wavelength by using the transverse offset technique. The triangular-profile fiber shows lower loss (≃0.25 dB/km at 1.55μm) under zero-tension and a larger spot size than the other fibers. However, the basket weave test showed the triangular-profile fiber incurred higher loss with tension than the other profiles.