Design of Air-Trenches/Holes Assisted Depressed-Core 12-Mode Fiber for Less MIMO Space Division Multiplexing

An air-trenches/holes assisted depressed-core few-mode fiber (AT-AH-DC-FMF) that features some asymmetrical air trenches, air holes and a depressed step-index core is proposed in this paper. The AT and DC can produce great contribution in separating the non-degenerated LP modes and spatial modes, thus suppressing the crosstalk efficiently. Based on AT and AH, the bending loss values of AT-AH-DC-FMF can be satisfied with the ITU-T recommendations of G. 654. The simulation results indicate that our proposed fiber can support 12 spatial modes with the effective index difference between adjacent LP modes (Delta n(eff)) larger than 1.03 x 10(-3) and the effective index difference between adjacent spatial modes (delta n(eff)) larger than 1.24 x 10(-4) The broadband characteristics such as Delta n(eff), delta n(eff), chromatic dispersion and effective mode field area (A(eff)) over the whole C and L band are comprehensively investigated. Moreover, fabrication methods and birefringence are detailed discussed. Our proposed AT-AH-DC-FMF possesses great potential to be applied to less multiple-input multiple-output (MIMO-less) space-division multiplexing (SDM), thus enlarging optical communication capacity and simplifying the system complexity.

Automated summary

This paper proposes a new type of optical fiber structure with air trenches, air holes, and a depressed step-index core for efficient mode separation. Simulation results show that the fiber can support up to 12 spatial modes with broadband characteristics.