Hybrid thermal Yagi-Uda nanoantennas for directional and narrow band long-wavelength IR radiation sources

Abstract

We investigate the possibility of spatially and spectrally controlling the thermal infrared emission by exploitation of the Yagi-Uda antenna design. Hybrid antennas composed of both SiC and Au rods are considered and the contributions of emission from all the elements, at a given equilibrium temperature, are taken into account. We show that the detrimental effect due to thermal emission from the not ideal parasitic elements drastically affect the performances of conventional thermal Au antennas in the 12 µm wavelength range. Nevertheless, our results show that the hybrid approach allows the development of efficient narrow-band and high directivity sources. The possibility of exploiting the Yagi-Uda design both in transmission and in reception modes, may open the way to the realization of miniaturized, efficient, robust and cheap sensor devices for mass-market applications.

Directional thermal emission and display using pixelated non-imaging micro-optics

“…1a ), by directional thermal emission, may open the door to enhanced radiative cooling 11 – 14 , thermal sensing 15 , 16 , thermophotovoltaics 17 , 18 , and incandescent infrared lighting 19 . Thus, directional thermal radiation was highly sought after 12 , 16 , 19 , 20 and has been realised over narrow spectral ranges with nanoscale structures such as phonon polariton gratings 20 – 22 , plasmonic metasurfaces 19 , 23 , 24 , nanoantenna 25 , 26 , and bull’s eye structures 27 , 28 . However, controlling narrowband thermal emission disregards much of the ideal blackbody thermal emission spectrum, severely reducing radiative efficiency (Fig.…”

Nondestructive Characterization at Nanoscopic Scale by Photoacoustic and Photothermal Techniques -INVITED

“…Photothermal radiometry and thermography can be also used to measure the emissivity of nanostructured materials, nanoantennas and metasurfaces which can be designed so to have specific directional thermal emittance properties [16,17].…”