High-Q enhancement of all-dielectric guided-mode resonance using 3D printing

All-dielectric guided-mode resonance (GMR) structures offer a promising route to achieving high-quality-factor (high-Q) resonances in the terahertz frequency range owing to their intrinsically low loss and strong spectral selectivity. Nevertheless, practical realization of high-Q GMR devices remains challenging because resonance performance is highly sensitive to fabrication imperfections. In this work, we present a 3D printing–based approach for enhancing the Q-factor of all-dielectric GMR structures while maintaining fabrication robustness. The proposed design strategy employs a quasi-bound-state-in-the-continuum–inspired configuration combined with multilayer dielectric stacking to suppress radiation leakage without requiring sub-micron fabrication accuracy. Fused deposition modeling (FDM) 3D printing is utilized to realize periodic dielectric structures using printable thermoplastic materials. The influence of material refractive index and absorption loss on resonance sharpening is systematically investigated. Terahertz time-domain transmission measurements reveal pronounced and narrow resonance features, confirming effective high-Q enhancement in the additively manufactured structures. These results demonstrate that 3D printing can be leveraged not only as a low-cost fabrication technique but also as an effective platform for engineering high-Q terahertz resonators. The presented approach provides a scalable and practical pathway for the development of all-dielectric GMR-based terahertz filters and sensing devices.