Bistable absorption in a 1D photonic crystal with a nanocomposite defect layer

Transmittance properties of one-dimensional metamaterial nanocomposite photonic crystal in GHz range

We have theoretically demonstrated and explored the transmittance characteristics of a one-dimensional binary photonic crystal composed of metamaterial (MM) and nanocomposite (NC) layers. The NC layer was designed from silver nanoparticles (Ag-NPs) in a host material as Yttrium oxide (Y2O3). Using the transfer matrix approach (TMM), the optical properties of a one-dimensional binary periodic structure having MM and NC layers in the Giga Hertz (GHz) range were examined. The filling fractions of nanoparticles have been explored to see their effect on the effective permittivity of NC materials. Furthermore, the transmittance properties of the suggested structure were investigated at various incident angles for the transverse electric (TE) polarization. In addition to that, different parameters, such as the thickness of the MM layer, the permittivity of the host dielectric material, the filling fraction, and the thickness of the NC layer are also taken into account. We also discussed the effect of these parameters on the width of the photonic bandgap (PBG). With the optimum values of the optical parameters of NC layer, this research could open the way for better photonic crystal circuits, splitters, switches and others.

Nonlinear control of switchable wavelength-selective absorption in a one-dimensional photonic crystal including ultrathin phase transition material-vanadium dioxide

Based on the transfer matrix theory, I realize a nearly perfect wavelength-selective absorption of near-IR waves in a one-dimensional defective photonic crystal, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(AB)^ND(BA)^M$$\end{document}(AB)ND(BA)M, containing a vanadium dioxide (VO\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_2$$\end{document}2) phase transition layer as a defect. Firstly, the effect of the period numbers, N and M, on the absorption spectrum is studied to achieve a perfect absorption peak. It is shown that optimal period numbers of the structure to maximize the absorption peak are N = 7 and M = 16. Our results also indicate that a narrow-band, almost perfect absorption is achieved due to the symmetry of the structure with respect to VO\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_2$$\end{document}2. Also, the absorption amount of the considered structure is about 50 times larger than that of a free-standing VO\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_2$$\end{document}2. Furthermore, the absorption peak value and resonant wavelength can be continuously tuned while VO\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_2$$\end{document}2 transits from semiconductor to metal phase at 340 K temperature. In addition, how different parameters such as the polarization and incident angle affect the absorption spectra is discussed. Finally, the nonlinear absorption spectra of the structure are graphically demonstrated beside the linear case. The current system can be applied in designing practical tunable optical devices such as IR sensors, limiters, and switches.