Azimuthal Fourier Decomposition for Loss Analysis of Hollow-Core Tube Lattice Fibers Part II: Tube Thickness Variation Effects

Abstract

<p>This is the pre-review draft of the second of two papers submitted to Journal of Lightwave Technology, where the effect on confinement loss of thickness variations along the perimeter of the tubes composing the cladding of inhibited-coupling guiding Tubular Lattice hollow-core fibers is investigated by using the Azimuthal Fourier Decomposition technique (developed in Part I) for the description of the cladding modal dynamics and their interaction with fundamental core mode. The results show that the thickness inhomogeneity affects the confinement loss spectrum through confinement loss increase and frequency red- and blue-shift of the high loss spectral regions. The magnitudes of the confinement loss increase and the high-loss region frequency shift strongly depend on the spatial distribution of the thickness inhomogeneity. The study provides insight into the loss mechanism of non-ideal tube lattice fibers, it allows quantifying the impact of such kind of structural deformations, identifying the route to make fibers more resilient to such fabrication imperfections, and highlighting once again the importance played in inhibited-coupling fibers by the interaction between core modes and the intricate set of cladding modes.</p>

Azimuthal Fourier Decomposition for Loss Analysis of Hollow-Core Tube Lattice Fibers Part I: Ideal Fibers

“…These series of papers (Part I, this paper, and part II following [27]) are motivated by the desire to fill, at least in part, this lack. In this paper we propose and develop an analysis method based on the Azimuthal Fourier Decomposition (AFD) of the fiber's modes.The method, when applied to ideal TLFs shows a good ability in predicting the TLFs loss and provides semianalytical expression for CL.…”

“…In this paper we propose and develop an analysis method based on the Azimuthal Fourier Decomposition (AFD) of the fiber's modes.The method, when applied to ideal TLFs shows a good ability in predicting the TLFs loss and provides semianalytical expression for CL. In the follow up paper [27] we apply the method for the analysis of the mechanisms and the impact of tube thickness variation on the TLFs transmission loss.…”