High-quality photonic crystals with a nearly complete band gap obtained by direct inversion of woodpile templates with titanium dioxide

Abstract

Photonic crystal materials are based on a periodic modulation of the dielectric constant on length scales comparable to the wavelength of light. These materials can exhibit photonic band gaps; frequency regions for which the propagation of electromagnetic radiation is forbidden due to the depletion of the density of states. In order to exhibit a full band gap, 3D PCs must present a threshold refractive index contrast that depends on the crystal structure. In the case of the so-called woodpile photonic crystals this threshold is comparably low, approximately 1.9 for the direct structure. Therefore direct or inverted woodpiles made of high refractive index materials like silicon, germanium or titanium dioxide are sought after. Here we show that, by combining multiphoton lithography and atomic layer deposition, we can achieve a direct inversion of polymer templates into TiO${}_2$ based photonic crystals. The obtained structures show remarkable optical properties in the near-infrared region with almost perfect specular reflectance, a transmission dip close to the detection limit and a Bragg length comparable to the lattice constant.

References in corpus (1)

• Signature of a three-dimensional photonic band gap observed on silicon inverse woodpile photonic crystals

Cited by in corpus (9)

• Light in correlated disordered media
• Experimental Tuning of Transport Regimes in Hyperuniform Disordered Photonic Materials
• Photonic hyperuniform networks by silicon double inversion of polymer templates
• Broadband near-infrared antireflection coatings fabricated by three dimensional direct laser writing
• Experimental probe of a complete 3D photonic band gap
• Reflectivity of Finite 3D GaAs Photonic Band Gap Crystals
• Scattering from controlled defects in woodpile photonic crystals
• Localization of light in a three-dimensional disordered crystal of atoms
• Fabrication of optical components with nm- to mm-scale critical features using three-dimensional direct laser writing