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Université de Fribourg

Transition from light diffusion to localization in three-dimensional amorphous dielectric networks near the band edge

Haberko, Jakub ; Froufe-Pérez, Luis S. ; Scheffold, Frank

In: Nature Communications, 2020, vol. 11, no. 1, p. 4867

AbstractLocalization of light is the photon analog of electron localization in disordered lattices, for whose discovery Anderson received the Nobel prize in 1977. The question about its existence in open three-dimensional materials has eluded an experimental and full theoretical verification for decades. Here we study numerically electromagnetic vector wave transmittance through realistic...

Université de Fribourg

Photonic hyperuniform networks obtained by silicon double inversion of polymer templates

Muller, Nicolas ; Haberko, Jakub ; Marichy, Catherine ; Scheffold, Frank

In: Optica, 2017, vol. 4, no. 3, p. 361–366

Hyperuniform disordered networks belong to a peculiar class of structured materials predicted to display isotropic complete photonic bandgaps for a refractive index contrast larger than 3. The practical realization of such photonic designer materials is challenging, however, as it requires control over a multi-step fabrication process on optical length scales. Here we report the direct-laser...

Université de Fribourg

Role of short-range order and hyperuniformity in the formation of band gaps in disordered photonic materials

Froufe-Pérez, Luis S. ; Engel, Michael ; Damasceno, Pablo F. ; Muller, Nicolas ; Haberko, Jakub ; Glotzer, Sharon C. ; Scheffold, Frank

In: Physical Review Letters, 2016, vol. 117, no. 5, p. 053902

We study photonic band gap formation in two-dimensional high-refractive-index disordered materials where the dielectric structure is derived from packing disks in real and reciprocal space. Numerical calculations of the photonic density of states demonstrate the presence of a band gap for all polarizations in both cases. We find that the band gap width is controlled by the increase in...

Université de Fribourg

The jamming elasticity of emulsions stabilized by ionic surfactants

Scheffold, Frank ; Wilking, James N. ; Haberko, Jakub ; Cardinaux, Frédéric ; Mason, Thomas G.

In: Soft Matter, 2014, vol. 10, no. 28, p. 5040–5044

Oil-in-water emulsions composed of colloidal-scale droplets are often stabilized using ionic surfactants that provide a repulsive interaction between neighboring droplet interfaces, thereby inhibiting coalescence. If the droplet volume fraction is raised rapidly by applying an osmotic pressure, the droplets remain disordered, undergo an ergodic–nonergodic transition, and jam. If the applied...

Université de Fribourg

Direct laser writing of three-dimensional network structures as templates for disordered photonic materials

Haberko, Jakub ; Muller, Nicolas ; Scheffold, Frank

In: Physical Review A, 2014, vol. 88, no. 4, p. 043822

In the present article we substantially expand on our recent study about the fabrication of mesoscale polymeric templates of disordered photonic network materials [Haberko and Scheffold, Opt. Expr. 21, 1057 (2013)]. We present a detailed analysis and discussion of important technical aspects related to the fabrication and characterization of these fascinating materials. Compared to our initial...

Université de Fribourg

Silicon hyperuniform disordered photonic materials with a pronounced gap in the shortwave infrared

Muller, Nicolas ; Haberko, Jakub ; Marichy, Catherine ; Scheffold, Frank

In: Advanced Optical Materials, 2014, vol. 2, no. 2, p. 115-119

The mesoscale fabrication of silicon hyperuniform disordered materials with a broad and pronounced photonic gap in the shortwave infrared is reported. Due to their unique structure and their high refractive index, these fascinating materials are predicted to possess a complete photonic bandgap in the absence of any long-range order.