Abstract-Tailoring Infrared Refractory Plasmonic Material to Broadband Circularly Polarized Thermal Emitter

Maowen Song, Honglin Yu, Jun Luo, Zuojun Zhang

http://link.springer.com/article/10.1007/s11468-016-0310-6
Circularly polarized (CP) thermal emission possesses huge application value in the fields of infrared detecting and polarimetric thermal imaging; however, the naturally occurring infrared source is incoherent and unpolarized. In this paper, we designed a broadband CP source adaptive for high temperature in consideration of the collision frequency of the electrons increasing with temperature. Compared with the structure proposed before, “I”-shaped resonators based on refractory plasmonic material generate the linearly polarized (LP) emission and the dielectric quarter-wave plate enhances the degree of emitted CP by suppressing the parasitic radiation. More than 80 % right-handed circularly polarized (RCP) emissivity in wavelengths ranging from 3.28 to 4.81 μm within 706 to 884 K is theoretically achieved.

Abstract-Highly efficient wavefront manipulation in terahertz based on plasmonic gradient metasurfaces

Jun Luo, Honglin Yu, Maowen Song, and Zuojun Zhang  »View Author Affiliations

Optics Letters, Vol. 39, Issue 8, pp. 2229-2231 (2014)
http://dx.doi.org/10.1364/OL.39.002229

http://www.opticsinfobase.org/ol/abstract.cfm?uri=ol-39-8-2229

Polarization conversion efficiency is vitally important to highly efficient wavefront manipulation based on phase discontinuities. However, previous single-layer phase gradient metasurfaces have suffered from low polarization conversion efficiency (at most 25%). Here we present a three-layer structure to enhance polarization conversion efficiency. The average efficiency is 76% for circularly polarized incident light converted to its opposite handedness. By arraying metallic antennas with varied optical axes for circularly polarized incident light, the efficiency of anomalous refraction is apparently increased, and the focused intensity of flat lenses can be significantly enhanced in the terahertz regime. It is expected that this scheme has potential applications in detection, focusing, and imaging.

© 2014 Optical Society of America