Diffraction of an obliquely incident TE-polarized Gaussian beams by equally spaced slits (finite lamellar grating)
with conducting substrate is treated. The substrate can be either vacuum or conductor. The diffracted and scattered
patterns, the transmission and reflection coefficients, and the normally diffracted energy are analyzed as a function of
several optogeometrical parameters. Particularly, the coupling between slits and the influence of the substrate is
considered. We have found that, when the substrate is a conductor the grating equation in reflection predicts with good
precision the angular positions of the orders of a finite grating; the angular positions of these orders are independents of
the beam width, the spot position on the finite grating, and the conductivity of the substrate. Besides, the envelope of the
reflected energy is conserved constant when the position of the spot is changed.
A rigorous numerical analysis of the diffraction of finite-size Hermite-Gaussian beams by two slits is presented. The case
of TM (Transversal Magnetic) polarization and oblique incidence is considered. We assume the double slit is ruled onto
a metallic screen of non-zero thickness h, width ℓ and separation d. Far-field spectra and transmission coefficients are
analyzed as a function of several opto-geometrical parameters, i.e. the wavelength λ, slit width ℓ and separation d.
Particular emphasis is put on the description of the energy diffracted along the incident direction Ei because of its
applications on optical-metrology. Finally, the validity of a well known scalar property Ei=2τ/λis studied within the vectorial regime.
Diffraction of an obliquely incident -polarized Gaussian beams by equally spaced slits (finite lamellar grating)
with conducting substrate is treated. The substrate can be either vacuum or conductor. The diffracted (transmitted)
patterns, the transmission coefficient, and the normally diffracted energy are analyzed as a function of several
optogeometrical parameters. Particularly, the coupling between slits and the influence of the substrate is considered. We
have found that, when the substrate is a conductor the grating equation in transmission predicts with good precision the
positions of the orders of diffraction of a finite grating; the angular positions of these orders are independents of the
beam width, the spot position on the finite grating, and the conductivity of the substrate.
We present FDTD calculations for transmission of electromagnetic waves through periodic arrays of slits in a
metallic screen. The results show resonant, frequency dependent, transmittance peaks for subwavelength
widths of the slits which can be up to a factor of ten with respect to those out of resonance. Although our
conclusions agree with previous work by Lezec and Thio as regards both the magnitude of the enhancement
and the lack of contribution of surface plasmon polaritons of the metal surface to this effect, we derive an
interpretation from a theory that deals with emerging beam-Rayleigh anomalies of the grating, and with Fabry-
Perot resonances of the perforated screen considered as an effective medium.
Proceedings Volume Editor (1)
This will count as one of your downloads.
You will have access to both the presentation and article (if available).
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.