Vanadium dioxide (VO2), with its well-known insulator-to-metal transition, offers a powerful mechanism for dynamically tuning optical responses. Leveraging this phase-change behavior, we theoretically propose and analyze a thermally tunable one-dimensional topological photonic crystal composed of a thin VO2 front layer integrated with alternating Al2O3 and Si dielectric layers. In this structure, topological behavior arises from distinct Zak-phase configurations and the associated bulk–boundary correspondence, enabling the formation of protected edge states through inversion- symmetry breaking between two photonic crystal sequences,( )ABBA N and( )BAAB N . Using the transfer-matrix method, we demonstrate that the VO2 phase transition induces pronounced temperature-dependent modulation in transmission, reflection, and absorption spectra. This transition enables dynamic control of the interface-localized topological mode, producing strong field confinement, spectral asymmetry, and real-time tunability of the edge state. The proposed configuration maintains robust optical performance under moderate thickness and polarization variations, highlighting its numerical stability despite the lack of experimental realization. Importantly, introducing VO2 as a front-layer element allows modulation of pre-existing topological edge states without altering the bulk Zak phase. This design achieves a transmission modulation depth of 56% and an absorption variation from 14% to 70% at ∼149 THz, while also outperforming non-topological VO2 structures in spectral stability (<0.1 THz shift) and resilience to ±5% structural disorder. Compared to earlier VO2-integrated photonic crystals that lack topological protection, the proposed platform enables reconfigurable operation suitable for thermal switching, adaptive NIR filtering, and optical memory, with prospects for sub-microsecond modulation using integrated heaters. Overall, these results establish VO2-based topological photonic crystals as promising, tunable, and robust candidates for next-generation adaptive photonic devices with thermally controlled spectral functionalities.
