ORCID Profile
0000-0001-8264-3250
Current Organisations
Jinan University
,
National Centre for Atmospheric Science
,
University of Reading
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Publisher: MDPI AG
Date: 25-12-2021
DOI: 10.3390/NANO12010055
Abstract: The advanced direct laser printing of functional devices with tunable effective index is a key research topic in numerous emerging fields, especially in micro-/nano-optics, nanophotonics, and electronics. Photosensitized nanocomposites, consisting of high-index materials (e.g., titanium dioxide, TiO2) embedded in polymer matrix, are emerging as attractive platforms for advanced additive manufacturing. Unfortunately, in the currently applied techniques, the preparation of optically functionalized structures based on these photosensitized nanocomposites is still h ered by many issues like hydrolysis reaction, high-temperature calcinations, and, especially, the complexity of experimental procedures. In this study, we demonstrate a feasible strategy for fabricating micro-/nanostructures with a flexibly manipulated effective refractive index by incorporating TiO2 nanoparticles in the matrix of acrylate resin, i.e., TiO2-based photosensitized nanocomposites. It was found that the effective refractive index of nanocomposite can be easily tuned by altering the concentration of titanium dioxide nanoparticles in the monomer matrix. For TiO2 nanoparticle concentrations up to 30 wt%, the refractive index can be increased over 11.3% (i.e., altering from 1.50 of pure monomer to 1.67 at 532 nm). Based on such a photosensitized nanocomposite, the grating structures defined by femtosecond laser nanoprinting can offer vivid colors, ranging from crimson to magenta, as observed in the dark-field images. The minimum printing width and printing resolution are estimated at around 70 nm and 225 nm, indicating that the proposed strategy may pave the way for the production of versatile, scalable, and functionalized opto-devices with controllable refractive indices.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0TC05578F
Abstract: Unprecedented data manipulation employed using a pH-stimuli responsive hydrogel was developed to achieve reversible data encryption–decryption.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0MH01207F
Abstract: A 3D laser printing technique for realizing unprecedented stereo-chiral-luminescent silver nanostructures was developed to achieve a record-high fluorescent anisotropic factor.
Publisher: IOP Publishing
Date: 16-11-2021
Abstract: Recent demonstrations of metasurfaces present their great potential to implement flat and multifunctional optical elements, which are accomplished with the designs of planar optics and micro-/nano- fabrications. Integrating metasurfaces in three dimensions has manifested drastically increasing advantages in manipulating light fields by extending design freedom. However, fabricating three-dimensional metasurfaces remain a tough challenge due to the lack of stereo printing protocols. Herein, we demonstrate laser nanoprinting of floated silver nanoparticle array in transparent hydrogel films for 3D metasurface to achieve color patterning. It is found that spatially resolved nanoparticles can be produced through laser induced photoreduction of silver ions and robustly anchored to the gel backbones by a focused femtosecond laser beam within a pH-responsive smart hydrogel matrix. With the aid of expansion properties of the pH-responsive hydrogel, repetitive coloration of the patterned plasmonic nanoparticle array over a wide spectrum range is achieved via reversible regulation of nanoparticle spacing from 550 to 350 nm and vice versa. This approach allows broadband 3D color-regulation in nanoscale for applications in active spectral filtering, information encryption, security tagging and biological colorimetric sensing, etc.
Publisher: Springer Science and Business Media LLC
Date: 18-10-2023
Publisher: Optica Publishing Group
Date: 11-01-2021
DOI: 10.1364/OL.413302
Abstract: Here, we demonstrate a flat nanofocalizer for converging light field into a uniform subwavelength light spot array based on the fractional Talbot effect by developing a direct laser writing technique with 3D fabrication precision. The fractional Talbot effect endows the device with the merits of high compression ratio and modular design capability for transforming a plane wave into arrayed light focal spots. By combining a synergistic laser printing technique, we introduce a buffer layer for improving the fabrication precision of structural height in favor of accurately manipulating the phase delay. For a given light wavelength at 750 nm, by precisely producing a nanofocalizer consisting of periodic unit elements with the dimensions of 300 ( w i d t h ) × 600 ( l e n g t h ) × 585 ( h e i g h t ) n m , we have achieved 5 × 6 light spot array with modular design, while the full width at half-maximum of a single focused light spot can be reduced to ∼ 0.82 λ . Our research may pave the way for realizing subwavelength optical devices capable of being readily integrated to existing optical systems.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Giorgio Graffino.