We address the problem of the transmission through subwavelength dielectric gratings. Following Maurel et al. [Phys. Rev. B 88, 115416 (2013)], the problem is reduced to the transmission by an homogeneous slab, either anisotropic (for transverse magnetic waves, TM) or isotropic (for transverse electric waves, TE), and an explicit expression of the transmission coefficient is derived. The optimum angle realizing perfect impedance matching (Brewster angle) is shown to depend on the contrasts of the dielectric layers with respect to the air. Besides, we show that the Fabry–Perot resonances may be dependent on the incident angle, in addition to the dependence on the frequency. These facts depart from the case of metallic gratings usually considered; they are confirmed experimentally both for TE and TM waves in the microwave regime.
© 2014 Optical Society of America
Diffraction and Gratings
Original Manuscript: December 20, 2013
Revised Manuscript: May 13, 2014
Manuscript Accepted: May 18, 2014
Published: June 18, 2014
Ahmed Akarid, Abdelwaheb Ourir, Agnès Maurel, Simon Félix, and Jean-François Mercier, "Extraordinary transmission through subwavelength dielectric gratings in the microwave range," Opt. Lett. 39, 3752-3755 (2014)