Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Focusing of electromagnetic waves through a dielectric interface

Not Accessible

Your library or personal account may give you access

Abstract

Given a time-harmonic electric-current distribution over a finite planar aperture situated in front of a dielectric half-space, the transmitted field in the dielectric half-space is calculated by the plane-wave-spectrum technique. We concentrate on the current distribution that focuses the electromagnetic energy into a small spot in the dielectric medium, such as in hyperthermia applications. Numerical results are given to illustrate the variation of spot size and of focal-point electric-field intensity as functions of polarization, scanning, and the permittivity of the half-space. We find that (1) the maximum electric-field intensity is not at the focal point but rather at a point closer to the aperture; for a small aperture, this focal shift may be more than one wavelength; (2) when the dielectric half-space is introduced, the 3-dB spot size changes according to the ratio of the wavelength in the half-space to that in the original aperture medium; and (3) the electric-field intensity at the focal point is greatest when the permittivity of the half-space is less than that of the aperture medium, not when the two media are electrically matched.

© 1984 Optical Society of America

Full Article  |  PDF Article
More Like This
Comparison of exact and asymptotic results for the focusing of electromagnetic waves through a plane interface

Velauthapillai Dhayalan and Jakob J. Stamnes
Appl. Opt. 39(34) 6332-6340 (2000)

Electromagnetic wave propagation through a dielectric–chiral interface and through a chiral slab

S. Bassiri, C. H. Papas, and N. Engheta
J. Opt. Soc. Am. A 5(9) 1450-1459 (1988)

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (14)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Equations (54)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved