TiS2 nanosheet-based nanofibers as superior low-threshold broadband optical limiters in the spectral range of 532 and 1064 nm
Optics and Laser Technology, cilt.204, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 204
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.optlastec.2026.116837
- Dergi Adı: Optics and Laser Technology
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Applied Science & Technology Source, Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: 2D materials, Nanofibers, Nonlinear absorption, Optical limiting, TiS2 nanosheets
- Ankara Üniversitesi Adresli: Evet
Özet
The development of materials with superior optical limiting capabilities is crucial for the protection of sensitive optical components from laser-induced damage. Two-dimensional (2D) transition metal dichalcogenides (TMDs) have been reported to exhibit optical limiting effects compared to benchmark materials such as fullerene and graphene owing to their unique properties. Until recently, their optical limiting performance has remainedlow and limited to a narrow spectral range. This study reports the optical limiting activity of the titanium disulfide (TiS2) nanosheet-based nanofibers using the Z-scan technique at 532 and 1064 nm. Nanofibers containingvarying concentrations of TiS2 nanosheets in a polyvinylpyrrolidone (PVP) matrix were fabricated by electrospinning . The incorporation of TiS2 nanosheets enhanced and broadened the linear absorption. Nonlinear absorption (NA) was observed over a broad spectral range from the visible to the near-infrared region (532–1064 nm), with the NA response becaming stronger as the TiS2 nanosheet concentration increased. Owingto the large bandgap of PVP (5.47 eV), the excitation wavelengths used were insufficient to induce direct valence band to conduction band transitions. At 532 nm, the NA response mainly arose from the combined effects of two photon absorption (TPA) and excited state absorption (ESA) . At 1064 nm, it was predominantly governed by higher-order multiphoton absorption processes. The NA enhancement provided by TiS2 mainly originated from its interband related states at 2.06 and 3.37 eV, which enabled efficient carrier excitation through wavelength-dependent interband and multiphoton absorption processes. Among the excitation wavelengths investigated, the NA response was stronger at 532 nm than at 1064 nm under ns excitation . Lowest optical limiting threshold values (OLT) of the TiS2 nanosheet-based nanofibers were determined to be 0.0028 J/cm2 at 532 nm and 0.010 J/cm2 at 1064 nm. Under fs excitation, the lowest OLT values were obtained at 700 nm and were found to be 0.0040J/cm2 for PVP/TiS2_1, 0.0032J/cm2 for PVP/TiS2_2, and 0.0025J/cm2 for PVP/TiS2_3 nanofibers. Their strong optical limiting response and low limiting thresholds make these TiS2 nanosheet-based nanofibers promising candidates for broadband optical limiting applications in both visible and near-infrared spectral regions.