Profile structure of single-mode fibers with low nonlinear properties for long-haul communication lines

Abstract

Special W-core ring (WCR) fiber profile structures with low nonlinear properties for long-haul communication lines are proposed. A single-mode dispersion-flattened fiber (DFF) design with effective core area larger than 55 μm 2 and low bending loss is presented. It is shown that based on this structure and small variation of outer diameter along the fiber length, it is possible to fabricate a continuous dispersion varying fiber (DVF) with average zero dispersion (less than 0.012 ps nm −1 km −1) in the spectral range 1.53–1.56 μm. Besides, a single-mode dispersion-shifted (DSF) fiber design with large effective core area over 75 μm 2 and low bending loss is proposed. By varying only the refractive index profile (RIP) of this fiber, a DSF with negative chromatic dispersion slope in the 1.55-μm range can be produced. It is shown that in this case an average chromatic dispersion of DVF, based on this DSF, does not exceed ±0.4 ps nm −1 km −1 in the spectral range 1.53–1.56 μm.