Numerical investigation of a tunable trilayer metalens on flexible all-dielectric metasurfaces via virtual bending at near-infrared wavelengths
Optics Communications, cilt.620, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 620
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.optcom.2026.133655
- Dergi Adı: Optics Communications
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: Flexible metasurface, Focusing efficiency, PDMS, Transformation optics, Tunable metalens, Virtual bending
- Kayseri Üniversitesi Adresli: Evet
Özet
Mechanically tunable metalenses on flexible substrates enable focal-length control, but physical deformation displaces meta-atoms from their designed phase-sampling positions and degrades wavefront fidelity. Here, we encode each target bending scenario at the design stage into an independent planar phase mask that preserves perfect meta-atom lattice integrity—an approach we term Virtual Bending-enabling full-wave analysis of the flexed response without curvilinear modeling. The designed TiO2/SiO2/TiO2 trilayer metalens achieves 88.92% static focusing efficiency with a Strehl ratio of 0.94 and a 0.035% focal-positioning error—among the highest numerically reported for flexible all-dielectric metalenses. Emulating convex bending from 10% to 50% of the aperture diameter spans a ∼201μm focal-tuning envelope while preserving lattice integrity; a phase-gradient analysis identifies Nyquist-limit sampling breakdown as the efficiency-limiting mechanism and establishes |∇Φ|max<4.0 rad/μm as a transferable design boundary. Furthermore, the architecture’s practical viability is corroborated by off-axis characterization up to ±15° and a rigorous three-pronged fabrication tolerance analysis. The static design maintains >77% efficiency across the 800–900 nm window, confirming chromatic robustness for VCSEL-integrated near-infrared systems such as time-of-flight depth sensing and adaptive micro-endoscopy.