We have experimentally and theoretically developed a unique thermally stimulated midinfrared source that emits radiation within a narrow range of wavelengths (δλ/λ⩽0.2). The emission wavelengths are defined by the periodicity of a metal coated silicon–air photonic crystal etched into the emitter surface. The lattice of the holes in the metal mediate the coupling of light into discrete surface plasmon states. This yields surfaces with spectrally nonuniform infrared reflection properties where over much of the IR 90+% of photons are reflected yet, in a narrow spectral region, 90% absorption is observed. Transfer matrix calculations simulate well the position and strength of the absorption features. This technology will afford tunable infrared emitters with high power in a narrow spectral band that are critical for sensing, spectroscopy, and thermophotovoltaic applications.

We demonstrate the continuous fabrication of large-area flexible metamaterial films via roll-to-roll (R2R) nanoimprint lithography (NIL) technique that can be conducted in an ambient environment at high speed. The plasmonic metal-insulator-metal structure is successfully fabricated by R2R NIL to continuously pattern the sub-wavelength scale metal disk array on flexible substrates. The patterned metal disks having varying diameters and sub-micron spacing with few defects lead to the desired broadband IR filtering performance at the designed dual-band, which correlates well with simulation analysis. Our method realizes a simple and high-throughput fabrication of plasmonic metamaterials for scalable and flexible optoelectronic and photonic applications.

No abstract

A metallodielectric architecture is employed to readily tailor the spectral properties of a bulk material for application to infrared sources and spectroscopic sensors. We exploit the interaction between surface plasmons at a metal interface with a photonic crystal in silicon to control the spectral response of the surface in reflection, absorption, and emission. The design uses Si-based thermally isolated suspended bridge structures fabricated using conventional photolithography techniques. The tunable narrow spectral response is defined by the symmetry and periodicity of the metallodielectric photonic crystal. Individual subresonances are recognized within this bandwidth. We model their origin through calculations of surface-plasmon modes in the metallic grating overlayer. Periodic arrays of holes in thin metal layers lead to coupled plasmons at the two metal–dielectric interfaces that, in turn, couple to modes in the underlying silicon–air photonic crystal. The model provides crucial physical insight into the interaction between surface plasmons and photonic crystals, with good agreement with the experimental results.

No abstract