Photonic hyperuniform networks obtained by silicon double inversion of polymer templates

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 writing of three-dimensional hyperuniform polymeric templates followed by a silicon double inversion procedure leading to high-quality network structures made of polycrystalline silicon. We observe a pronounced gap in the shortwave infrared centered at a wavelength of lambda(Gap) similar or equal to 2.5 mu m, in good agreement with numerical simulations. In the experiments the typical structural length scale can be varied between 2 and 1.54 mu m, leading to a blueshift of the gap accompanied by an increase of the silicon filling fraction. (C) 2017 Optical Society of America