All-metallic three-dimensional photonic crystals with a large infrared bandgap

Abstract

Three-dimensional (3D) metallic crystals are promising photonic bandgap structures: they can possess a large bandgap, new electromagnetic phenomena can be explored, and high-temperature (above 1,000 degrees C) applications may be possible. However, investigation of their photonic bandgap properties is challenging, especially in the infrared and visible spectrum, as metals are dispersive and absorbing in these regions. Studies of metallic photonic crystals have therefore mainly concentrated on microwave and millimetre wavelengths. Difficulties in fabricating 3D metallic crystals present another challenge, although emerging techniques such as self-assembly may help to resolve these problems. Here we report measurements and simulations of a 3D tungsten crystal that has a large photonic bandgap at infrared wavelengths (from about 8 to 20 microm). A very strong attenuation exists in the bandgap, approximately 30 dB per unit cell at 12 microm. These structures also possess other interesting optical properties; a sharp absorption peak is present at the photonic band edge, and a surprisingly large transmission is observed in the allowed band, below 6 microm. We propose that these 3D metallic photonic crystals can be used to integrate various photonic transport phenomena, allowing applications in thermophotovoltaics and blackbody emission.

Thermal emission from three-dimensional arrays of gold nanoparticles

“…thermally driven spontaneous emission, promising applications in imaging, sensing and most importantly, in thermophotovoltaics (TPV). 1,2,3,4,5,6,7,8,9 Control of thermal emission can also be achieved by means of microstructured engineering on silicon 10,11,12,13 or metal surfaces. 14 Depending on the type of application, photonic crystals and structured surfaces can act as narrow-or wide-band, directional or isotropic thermal emitters.…”

Simulating photons and plasmons in a three-dimensional lattice

“…Such a geometry has recently attracted interest as a possible means to fabricate media with negative permittivity [8]. Each conductor of cross-section a 3 × a 3 is aligned to the principal axes of the a×a×a cell.…”

Radiative Cooling: Principles, Progress, and Potentials

“…However, it may be highly challenging to satisfy this condition with the intrinsic IR absorptions in bulk materials and engineered IR absorption within planar photonic devices. Alternatively, highly selective emission can be achieved in artificially designed metallic nano/microstructures, such as, plasmonic structures,64, 65, 66, 67, 68, 69, 70, 71 metallic photonic crystals,72, 73, 74, 75 and metamaterials 76, 77, 78, 79, 80. However, tuning the emission of these microstructures to achieve selective IR emission covering the entire 8–13 μm wavelengths range can still be a significant challenge.…”