Papers by Keyword: Mid-Infrared

Abstract: The material of doping transition metal (TM) in chalcogenide compound such as ZnS and ZnSe can be used in sensors, nonlinear optics, optical thin-films and mid-infrared area because of their faster optical response time, wider transparency range of mid-infrared and higher mid-infrared transmittance, low optical loss and phonon energy. In this paper, the ceramic targets of (ZnS/Se)_0.4(Co)_x(Ga₂O₃)_0.6-x (x=0.1, 0.3 and 0.5) were prepared by high temperature solid state reaction. The mass loss rate, shrinkage rate and molar ration were calculated. XRD, absorption spectrum and AFM&OM were investigated. All of the results are shown that the optimum doping concentration is (ZnS/Se)_0.4(Co)_0.5(Ga₂O₃)_0.1 (namely x=0.5), and the optimum intering temperature are in the range 1000~1200°C. Besides, the zinc-blende structure on ceramics targets was confirmed by XRD. A broad application range from VIS to Mid-infrared was suggested by absorption spectra. The optimal base material ZnSe was proved by AFM and OM. All these results indicate that bulks of (ZnS/Se)_0.4(Co)_x(Ga₂O₃)_0.6-x are most promising materials in future

Abstract: In this paper, we present two metamaterial absorbers (MMA) at mid-infrared using multi-resonant structures. The dual band MMAs employ the typical metal/dielectric/metal structure with 80 nm gold ground plane at the bottom, 190 nm SiO₂ dielectric spacer in the middle and periodic gold patterns on top. The top resonant structure in MMA1 consists of a gold cross resonator ringed by four gold split-ring resonators (SRR) at the ends of the cross, while in the unit cell of MMA2, gold SRRs are placed at the four quadrants of the cross resonator. MMA1 shows two absorption peaks of 90.3% and 88.4% at 4.17μm and 4.86μm respectively, and the absorption peaks of MMA2 are observed to be 72.4% at 3.90μm and 48.0% at 5.66μm.

Abstract: This paper reports the enhancement of the electrochromic properties in the infrared, IR, region of radio frequency sputtered WO3 thin films thanks to a careful optimization of the deposition conditions. From the combination of various techniques of characterization, the optical performances, in particular, the contrast in reflectance between the inserted state and the deinserted one, upon cycling in H3PO4 liquid electrolyte, are correlated to the film morphology and composition. Films, grown in higher chamber pressure, exhibiting a lower density and a O/W ratio higher than 3, show the most promising behavior. Finally, first trends on the incorporation of the WO3 single layer in full electrochromic devices are discussed.