2D Optical Gratings Based on Hexagonal Voids on Transparent Elastomeric Substrate

Piccolo, Valentina; Chiappini, Andrea; Armellini, Cristina; Barozzi, M.; Łukowiak, Anna; Sazio, Pier-John A.; Vaccari, Alessandro; Ferrari, Maurizio; Zonta, Daniele

doi:10.3390/mi9070345

Cited by 14 publications

(8 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This pattern was attributed to diffraction from the outer (111) layer in well-ordered CCAs . Discrete spots arranged in a hexagonally symmetric pattern have also been observed for close-packed FCC PS PhCs, 2D optical gratings, and 2D photonic crystals with a hexagonal lattice. , …”

Section: Results and Discussionmentioning

confidence: 69%

“…This pattern was attributed to diffraction from the outer (111) layer in well-ordered CCAs. 23 Discrete spots arranged in a hexagonally symmetric pattern have also been observed for close-packed FCC PS PhCs, 68 2D optical gratings, 69 and 2D photonic crystals with a hexagonal lattice. 18,70 Thus, we posit that the hexagonal symmetry of the 213 nm laser diffraction from our IO arises from the 2D hexagonal symmetry of the outer (111) planes.…”

Section: Acs Applied Nano Materialsmentioning

confidence: 78%

See 1 more Smart Citation

Colloidal Self-Assembly of Highly-Ordered Silica Inverse Opals for Deep Ultraviolet Diffraction

Pallares

Rout

Deering

et al. 2020

ACS Appl. Nano Mater.

View full text Add to dashboard Cite

The fabrication of highly ordered ∼2 μm thick silica inverse opal (IO) photonic crystal (PhC) films is reported. These IO films diffract deep ultraviolet light (UV, <250 nm) and are prepared using the inward-growing self-assembly of ∼143 nm diameter monodisperse polystyrene nanoparticles (PSNPs) suspended within a hydrolyzed silicate sol–gel precursor solution. Removal of the PSNPs results in solid, robust IOs that attenuate >70% of light meeting the Bragg condition at normal incidence. Structural and optical characterization of these silica IO films indicate that noncoherent scattering losses are low at deep UV wavelengths, even though substantial crack-type defects occur. The IO films exhibit a diffraction fwhm of ∼12 nm with diffraction efficiencies of >30% for 213 nm laser light and possess nanoscale porosities of ∼20 nm. Relative to reported silica IOs that diffract deep UV light, these new PhC materials show at least 28% narrower spectral bandwidths and 5-fold increased diffraction efficiencies. We postulate that increased ordering of the silica network is the principal factor that improves the optical performance. Furthermore, the relatively flat, homogeneous IO film surfaces produce narrow, symmetric diffraction beams suitable for optical imaging applications. Strategies to further improve the diffraction efficiencies of these silica IO materials and the implications for novel technological applications are discussed.

show abstract

Section: Results and Discussionmentioning

confidence: 69%

Section: Acs Applied Nano Materialsmentioning

confidence: 78%

Colloidal Self-Assembly of Highly-Ordered Silica Inverse Opals for Deep Ultraviolet Diffraction

Pallares

Rout

Deering

et al. 2020

ACS Appl. Nano Mater.

View full text Add to dashboard Cite

show abstract

“…Another example of chromatic 2D system, obtained by colloidal crystal lithography, was proposed recently by Piccolo et al [108,109], who developed a strain/stress vectorial sensor based on quasi-hemispherical voids in a hexagonal arrangement on a transparent flexible PDMS substrate, as shown in Figure 12. In this case, too, it is possible to acquire the vectorial strain-stress information in the two directions by means of the analysis of the displacement of two different diffraction spots.…”

Section: Mechanochromic Sensors Based On Photonic Crystalsmentioning

confidence: 99%

Photonic Crystal Stimuli-Responsive Chromatic Sensors: A Short Review

et al. 2020

Self Cite

View full text Add to dashboard Cite

Photonic crystals (PhC) are spatially ordered structures with lattice parameters comparable to the wavelength of propagating light. Their geometrical and refractive index features lead to an energy band structure for photons, which may allow or forbid the propagation of electromagnetic waves in a limited frequency range. These unique properties have attracted much attention for both theoretical and applied research. Devices such as high-reflection omnidirectional mirrors, low-loss waveguides, and high- and low-reflection coatings have been demonstrated, and several application areas have been explored, from optical communications and color displays to energy harvest and sensors. In this latter area, photonic crystal fibers (PCF) have proven to be very suitable for the development of highly performing sensors, but one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) PhCs have been successfully employed, too. The working principle of most PhC sensors is based on the fact that any physical phenomenon which affects the periodicity and the refractive index of the PhC structure induces changes in the intensity and spectral characteristics of the reflected, transmitted or diffracted light; thus, optical measurements allow one to sense, for instance, temperature, pressure, strain, chemical parameters, like pH and ionic strength, and the presence of chemical or biological elements. In the present article, after a brief general introduction, we present a review of the state of the art of PhC sensors, with particular reference to our own results in the field of mechanochromic sensors. We believe that PhC sensors based on changes of structural color and mechanochromic effect are able to provide a promising, technologically simple, low-cost platform for further developing devices and functionalities.

show abstract

“…This is used in diffraction experiments. In diffraction studies by other groups, air-filled hemispherical voids in a periodic lattice have been prepared using silanization and etching [9,10]. However, neither the quality of diffraction from 2D metasurfaces containing air-filled pockets nor the conditions for their wide-angle far-field diffraction has been studied earlier, to the best of our knowledge.…”

Section: Introductionmentioning

confidence: 99%

Light Diffraction From a Flexible Patterned Layer With Periodically Arranged Dimples

Haldar

Vijaya

2020

IEEE Photonics J.

View full text Add to dashboard Cite

Patterns with periodically arranged dimples are fabricated by an inexpensive soft-imprint lithography technique on a flexible transparent polymer substrate. Excellent diffraction characteristics, with highly intense and fine features, are seen from these polymer layers in transmission, even though the effective refractive index variation across their thickness is very small. The diffraction is studied at two different feature sizes and at multiple wavelengths. The results from the experiment emphasize that the diffraction is a 2-D spatial Fourier transform of the object but with some important limitations. Numerical calculation based on rigorous coupled-wave analysis exactly reproduces the results and supports the features of the experiment such as unequal intensity distribution in the diffraction pattern.

show abstract

2D Optical Gratings Based on Hexagonal Voids on Transparent Elastomeric Substrate

Cited by 14 publications

References 23 publications

Colloidal Self-Assembly of Highly-Ordered Silica Inverse Opals for Deep Ultraviolet Diffraction

Colloidal Self-Assembly of Highly-Ordered Silica Inverse Opals for Deep Ultraviolet Diffraction

Photonic Crystal Stimuli-Responsive Chromatic Sensors: A Short Review

Light Diffraction From a Flexible Patterned Layer With Periodically Arranged Dimples

Contact Info

Product

Resources

About