Transfer-Matrix Approach Based on Modal Analysis for Modeling Corrugated Long-Period Fiber Gratings
Journal
Applied Optics
Journal Volume
40
Journal Issue
25
Pages
4476-4486
Date Issued
2001-09
Author(s)
Abstract
A transfer-matrix method is developed for modeling a corrugated long-period fiber grating. Claddingmode resonance in such a corrugated structure can be controlled by the applied tensile stress based on the photoelastic effect. A first-order vectorial perturbation expansion is used to derive the mode fields of the two basic regions under the strain-induced index perturbation. Because the etched cladding radius is much smaller than the unetched radius, the effect of the corrugated structure on cladding modes cannot be treated as a small perturbation. Thus the conventional coupled-mode theory is inadequate for the modeling of such a structure. Based on a self-consistent mode-matching technique, mode coupling within the corrugated structure can be described by a set of transfer matrices. We apply the formulation to the calculation of the transmission spectra of a corrugated long-period grating and compare the calculated with the experimental results. The transfer-matrix approach is found to account well for the features of the transmission spectra of the corrugated long-period gratings. © 2001 Optical Society of America.
SDGs
Other Subjects
Cladding (coating); Light transmission; Matrix algebra; Maxwell equations; Modal analysis; Photoelasticity; Tensile stress; Long-period fiber gratings (LPFG); Fiber Bragg gratings
Type
journal article