This study investigates the Goos–Hänchen (GH) shift in a one-dimensional photonic crystal (1DPC) structure containing a single Weyl semimetal (WSM) layer as a defect. The proposed configuration, represented as , functions as a symmetric Fabry–Perot (s-FP) interferometer. The reflection coefficient for a TM-polarized incident wave is calculated using the transfer matrix method, and the GH shift is extracted from the phase variation of the reflected wave. By analyzing the real part of the WSM’s permittivity, the reflection spectrum, phase response, and GH shift are systematically examined. The results reveal that both the Fermi energy and the number of Weyl nodes ( ) significantly influence the magnitude of the GH shift and can be tuned to control the incident angle at which the maximum displacement occurs. Specifically, as the Fermi energy increases, the magnitude of the GH shift increases; conversely, as the parameter increases, the GH shift magnitude decreases. These findings offer a promising route for the development of tunable optical devices based on the GH effect.
