Design of Bend-Limited Large-Mode Area Dispersion Shifted Few-Mode Fiber for Fast Communication

We propose the novel design of ring core dispersion-shifted fiber (RC-DSF) for a few-mode operation. The design claims to support four linearly-polarized (LP) modes such as LP
₀₁
, Lp
₁₁
, LP
₀₂
, and LP
₃₁
over C+L-band with large-mode-area and low bending-loss. We numerically exhibit the design principles of RC-DSF and compare the results with the triangular profile DSF that supports only the fundamental LP
₀₁
mode with the lesser effective area. The modal properties of the proposed fiber have been investigated by using a finite difference method based solver. The proposed RC-DSF attains an effective area 250 μm
²
and bending-loss 0.002dB/km for LP
₀₁
mode witha bending radius of 20 mm at 1550 nm. The dispersion parameter is nearly zero at 1550 nm and the differential-mode group-delay(DMGD) between the guided modes is less than 0.04 ps/m. With this modal properties, the proposed few-mode fiber (FMF) can be chosen as a suitable agent for mode-division multiplexing (MDM).