Polarization-maintaining few mode fiber composed of a central circular-hole and an elliptical-ring core

Abstract

We propose a novel waveguide design of polarization-maintaining few mode fiber (PM-FMF) supporting ≥10 non-degenerate modes, utilizing a central circular air hole and a circumjacent elliptical-ring core. The structure endows a new degree of freedom to adjust the birefringence of all the guided modes, including the fundamental polarization mode. Numerical simulations demonstrate that, by optimizing the air hole and elliptical-ring core, a PM-FMF supporting 10 distinctive polarization modes has been achieved, and the effective index difference Δn eff between the adjacent guided modes could be kept larger than 1.32 × 10 −4 over the whole C L band. The proposed fiber structure can flexibly tailored to support an even larger number of modes in PM-FMF (14-mode PM-FMF has been demonstrated as an example), which can be readily applicable to a scalable mode division multiplexing system.

Bragg Grating Assisted Sagnac Interferometer in SiO2-Al2O3-La2O3 Polarization-Maintaining Fiber for Strain–Temperature Discrimination

“…Since the birefringence in the SAL PMF is induced by the asymmetric thermal stress through elasto-optical effect, the internal thermal stress of the fiber and the consequent phase birefringence were numerically analyzed by using the solid mechanics and wave optics modules in COMSOL Multiphysics [ 26 , 27 ]. The detailed parameters of the fiber’s structure and materials are listed in Table 1 .…”

Mode Division Multiplexing Based on Ring Core Optical Fibers

“…L. Wang et al [47] proposed an elliptical RCF design that could support up to 10 guided vector modes over the entire C band and eight higher-order vector modes were all separated from their adjacent modes by Δneff >10 −4 , except for the two fundamental modes, as its schematic diagram of the fibre cross section shown in Fig.5(a). In order to further separate the two fundamental modes, J. Zhao et al proposed a design of elliptical RCF utilizing a central circular air hole which could support 14 distinctive polarization modes including the two fundamental modes with adjacent modal Δneff > 1.2×10 −4 (including the fundamental modes) over the whole C+L band [48].…”

Fiber transmission demonstrations in vector mode space division multiplexing

“…Consequently, we accept that the fundamental mode would not be polarization maintaining. Subsequently, introducing a central air hole has been proposed to lift this degeneracy [13]; to our knowledge, no experimental demonstration has yet been reported.…”