A Detailed Theoretical Study of the Anomalies of a Sinusoidal Diffraction Grating

Abstract

Theoretical counterparts are presented for the experimental efficiency curves obtained by Hutley and Bird in the visible region for a holographic grating covered consecutively with films of silver, aluminium and gold. It is thus shown that the recently developed formulation of Maystre, which takes into account the finite conductivity of the grating surface, gives results in quantitative agreement with experiment . This not only validates the theory, but also demonstrates that the difficulties associated with profile determination and oxide films, which have in the past led some experimenters to renounce the visible region and perform measurements on millimetre-wave gratings, are not in fact insuperable . It is also shown that only a theoretical model which takes into account groove depth effects can hope to predict accurately the locations of regions of enhanced energy absorption by gratings .

On Rayleigh's Theory of Sinusoidal Diffraction Gratings

“…The experiments of Hutley and Bird [115] [116] and Neviere et al . [117] have convincingly demonstrated that there are important differences in the way infinite conductivity and finite conductivity gratings scatter .…”

Localized surface plate modes via flexural Mie resonances

“…Consequently, it can be shown that the corrugated metal structure is equivalent to a uniform structure with material properties, which can be approximated by the Drude metal with a plasma frequency that depends only on the shape and dimensions of the corrugations. This is the analog of surface plasmons in diffraction gratings and their inner relation to Wood's anomaly [18][19][20]. Pendry's work was almost immediately followed by the experimental demonstration of spoof plasmons at microwave frequencies * mfarhat@hbku.edu.qa [21] and several other studies focusing on various structures capable of supporting spoof plasmons [22][23][24][25][26].…”

“…The scattering coefficients A l associated with this structure are deduced from Eqs. (18)- (20) and σ scat is again computed using Eq. (11).…”

Extinction-theorem analysis of diffraction anomalies in overcoated gratings

“…forTM (35 ) and multiplication of Y I with the characteristic matrix of the multilayer results in a real A and imaginary B value in Equation (21).…”