Flexible photonic devices based on dielectric antennas

Abstract

Flexible and stretchable photonics are emerging fields aiming to develop novel applications where the devices need to conform to uneven surfaces or whenever lightness and reduced thickness are major requirements. However, owing to the relatively small refractive index of transparent soft matter including most polymers, these materials are not well adapted for light management at visible and near-infrared frequencies.Here we demonstrate simple, low cost and efficient protocols for fabricating Si 1−x Ge x -based, sub-micrometric dielectric antennas over record scales (50 mm wafers) with ensuing hybrid integration into different plastic supports. The transfer process has a near-unity yield: up to 99.94% for disordered structures and 99.5% for the ordered counterpart. Finally, we benchmark the optical quality of the dielectric antennas with light scattering measurements, demonstrating the control of the islands structural color and the onset of sharp Mie modes after encapsulation in plastic. Thanks to the ease of implementation of our fabrication methods, these results are relevant for the integration of SiGe-based dielectric Mie resonators in flexible substrates over large surfaces.

Solid-State Dewetting Dynamics of Amorphous Ge Thin Films on Silicon Dioxide Substrates

“…The nano-islands formed are crystalline. The a-Ge film dewetting dynamics, while resulting in a similar array of isolated nano-islands as in the c-Ge case [ 1 , 3 , 5 ], is subjected to an additional driving force: the energy gain due to the crystallization process. The crystalline seeds act as effective collectors of diffusing Ge atoms, evolving into nanometer-size islands.…”

“…Germanium continuous thin films are in a metastable state of equilibrium. As such, they can be transformed into isolated nano-islands or more complex architec-tures by annealing at high temperature [ 1 , 2 , 3 ]. The metamorphosis of the crystalline thin film into nanocrystals is kinetically controlled by surface diffusion [ 4 ].…”

Scalable Disordered Hyperuniform Architectures via Nanoimprint Lithography of Metal Oxides

“…Very recently, spinodal-like solid-state dewetting of SiGe alloys on SiO2 was demonstrated as an alternative, self-assembly method for the fabrication of high-dielectric constant, effectively dHU metasurfaces 31 . The advantage of this approach is the lack of constraints in the extension of the dewetted wafers 32 that, in principle, can be extended up to 8 inches using state-of-the-art molecular beam epitaxy reactors. Nevertheless, the implementation of dHU architectures made of such hard materials and having a typical size that can be tuned at will from tens of nm up to tens of m can be conveniently exploited as masters for nano-imprint lithography 33 .…”

“…Very recently, spinodal-like solid-state dewetting of SiGe alloys on SiO 2 was demonstrated as an alternative, self-assembly method for the fabrication of high-dielectric constant, effectively dHU metasurfaces . The advantage of this approach is the lack of constraints in the extension of the dewetted wafers that, in principle, can be extended up to 8 in. using state-of-the-art molecular beam epitaxy reactors.…”

Third-harmonic light polarization control in magnetically-resonant silicon metasurfaces

“…Thanks to the improved accuracy of nanofabrication techniques, it is nowadays possible to obtain high quality nano-objects consisting of metals or dielectric materials to manipulate light in the visible and near-infrared regimes [8]. The applications of metasurfaces include beam steering [9,10], light focusing [11,12], holography [13], and sensing [14].…”