Strain Effect Study on Mode Field Diameter and Effective Area of WII Type Single Mode Optical Fiber

Abstract

In this article, the effect of strain on mode field diameter (MFD) and effective area (A eff ) in a modern multilayer WII type single mode optical fiber is investigated. The modal analysis of the fiber structure is based on linear polarized (LP) approximation method. The simulation results depict that both mode field diameter and effective area grow as a result of increment in tensile strain. The overall effect is observed in a slight rise in quality factor (Q f ) of the fiber. Likewise, enlargement in amplitude of compressive strain leads to decrement in MFD and A eff . However, among the optical and geometrical parameters of the fiber structure, Δ has the most considerable impact on both MFD and A eff variation whilst R 1 shows the least effect. In other words, any shift in the value allocated to Δ results in substantial change in the MFD and A eff alteration due to strain. To eliminate this effect, the higher amounts for Δ are preferable which is related to the layering structure of the WII type optical fiber.

Strain and Curvature Stability Enhanced SMF Introduction

“…The strain sensitivities of the MFD and A eff at 1.55µm are 1.8 pmµɛ -1 and 6.3 × 10 -6 µm 2 µɛ -1 respectively. Noting the results reported in [18,[22][23][24] the transmission characteristics of the proposed structure exhibit high stability to external strain application. The effective area of the designed optical fiber is about 58µm 2 which is large for bend insensitive single-mode optical fibers.…”

“…10 application of tensile and compressive strains result respectively in reduction and increment in the refractive index and thus the effective refractive index experiences same trends, either. It is useful to mention that the n eff sensitivity to strain is smaller than the results presented in [18,[22][23][24]. It is due to using of special cost function which enhanced the stability of the structure to strain.…”

“…Moreover, there is a boost in n eff sensitivity to strain which is calculated to be -6.7 × 10 -8 µɛ -1 . This sensitivity is still of better stability compared to the results exhibited in [18,[22][23][24]. Despite the noticeable difference in the refractive index profiles of the two structures, the fibers designed according to Figure 1 and Figure 6, exhibit almost the equal MFDs.…”

Multicore fibers for sensing applications

“…(2.3) equals to the unit. The refractive index change of the pure silica caused by photo-elastic effect can be described by [40][41][42]: Due to the thermal-optic effect and thermal expansion effect, the temperature change will also result in the Bragg wavelength shift, which can be described as [47]:…”