Modeling transmittance through submicron silver slit arrays

Abstract

Mid-infrared transmittance of submicron silver slit arrays was numerically studied with the finite difference time domain method. The slit width varies from 50 nm to 300 nm and a square feature may attach at either or both slit sides. Although the side length of features is one or two orders of magnitude shorter than the wavelength, the attached nanoscale features can modify the transmittance significantly. The transmittance was also further investigated in detail by looking into the electromagnetic fields and Poynting vectors of selected slit geometries. The investigation results show that such change can be attributed to the cavity resonance effect inside the slit arrays. The work is of great importance to the wavelength-selective devices design in optical devices and thermal application fields.

Keywords

finite difference time domain method / transmittance / silver slit array / cavity resonance effect

References

[1] ZhangZ. M.Nano/microscale heat transfer [M], 2007New YorkMcGraw-Hill32-47

[2] ChenY. B., LeeB. J., ZhangZ. M.. Infrared radiative properties of submicron metallic slits [J]. Journal of Heat Transfer, 2008, 130(8): 082404-082411

[3] CrouseD., KeshavareddyP.. Polarization independent enhanced optical transmission in one-dimensional gratings and device applications [J]. Optical Express, 2007, 15(4): 1415-1427

[4] LeeB. J., ChenY. B., ZhangZ. M.. Confinement of infrared radiation to nanometer scales through metallic slit arrays [J]. Journal of Quantitative Spectroscopy and Radiative Transfer, 2008, 109(4): 608-619

[5] PendryJ. B.. Radiative exchange of heat between nanostructures [J]. Journal of Physics: Condensed Matter, 1999, 11(35): 6621-6628

[6] MoreauA., LafargeC., LaurentN., EdeeK., GranetG.. Enhanced transmission of slit arrays in an extremely thin metallic film [J]. Journal of Optics A: Pure and Applied Optics, 2007, 9: 165-169

[7] CrouseD., KeshavareddyP.. Role of optical and surface plasmon modes in enhanced transmission and applications [J]. Optics Express, 2005, 13(20): 7760-7771

[8] MinC. J., JiaoX. J., WangP., MinH.. Investigation of enhanced and suppressed optical transmission through a cupped surface metallic grating structure [J]. Optics Express, 2006, 14(12): 5657-5663

[9] DiSi.The study of extraordinary transmission behavior in sub-wavelength metallic slit [D], 2006BeijingBeijing Jiaotong University

[10] LiZ.-bin.Optical transmission behavior in periodically sub-wavelength structures [D], 2008TianjinNankai University

[11] KongX.-t., LiZ.-b., TianJ.-guo.. Interaction of light and cavity structures in metal film [J]. China Science Paper Online, 2010, 7: 1-7

[12] LeeB. J., ChenY. B., ZhangZ. M.. Transmission enhancement through nanoscale metallic slit arrays from the visible to mid-infrared [J]. Journal of Computational and Theoretical Nanoscience, 2008, 5(2): 201-213

[13] BarbaraA., QuemeraisP., BustarretE., Lopez-RiosT.. Optical transmission through subwavelength metallic gratings [J]. Physics Review B, 2002, 66(16): 161403-161412

[14] OrdalM. A., LongL. L., BellR. J., AlexanderR. W., WardC. A.. Optical properties of the metals Al, Co, Cu, Au, Fe, Pb, Ni, Pd, Pt, Ag, Ti, and W in the infrared and far infrared [J]. Applied Optics, 1983, 22(7): 1099-1119

[15] PalikE. D.Handbook of optical constants of solids [M], 1998San DiegoAcademic Press436-441

[16] YehP.Optical waves in layered media [M], 1988New YorkWiley154-162

[17] TaflovA., HagnessS. C.Computational electrodynamics: The finite-difference time-domain method [M], 20053rd ed.BostonArtech House75-110

[18] KunzK. S., LubbersR. J.The finite difference time domain method for electromagnetics [M], 1993Boca RatonCRC Press214-220

[19] WangA. H., CaiJ. J.. Modeling radiative properties of nanoscale patterned wafers [J]. China Science: Technological Sciences, 2010, 53(2): 352-359

[20] WangA. H., CaiJ. J.. Pattern scaling effect on the radiative properties of Wafer’s surface [J]. China Science: Technological Sciences, 2010, 53(7): 1886-1892

[21] WangA. H., HsuP. F., ChenY. B., CaiJ. J.. Effect of nanoscale features on infrared radiative properties of heavily doped silicon complex gratings [J]. China Science: Technological Sciences, 2010, 53(8): 2207-2214