Synopsis: A New Window on Nanometer Apertures

Experiment and theory combine to give a more complete picture of a fundamental problem in diffraction optics.
Synopsis figure
J. Yi et al., Phys. Rev. Lett. (2012)

Several precision optical techniques, such as high-resolution near-field scanning microscopy, depend on nanometer-sized holes to guide electromagnetic waves. Scientists have studied diffraction through subwavelength apertures since the 17th century, yet despite extensive effort, theory has not entirely accounted for the electromagnetic behavior of holes in real metals with finite thicknesses and dielectric constants. In a paper in Physical Review Letters, Juemin Yi, at the University of Strasbourg, France, and colleagues wrap up the problem in a complete package of theory and experiment.

Apertures large compared to the wavelength of electromagnetic waves yield their secrets to a rather straightforward theoretical approach, but when the holes become close to or smaller than the wavelength, the calculations become trickier. Moreover, experimental study is complicated by actual physical implementations involving real materials with a finite thickness rather than infinitely thin metal plates. Yi et al. conducted experiments in which they measured the full diffraction patterns of a circular aperture all the way from large holes down to subwavelength openings in realistic structures.

To accurately understand their observations, the authors find that not only do collective electron oscillations—the surface plasmons—need to be dealt with, but the interaction of the plasmons with waveguide modes of the aperture have to be included. Yi et al. derive a set of simple expressions that make it more straightforward to estimate the total transmission of light through a hole from measurements made along a single direction, as opposed to having to integrate over a wide range of angles. – David Voss


Features

More Features »

Announcements

More Announcements »

Subject Areas

OpticsNanophysics

Previous Synopsis

Next Synopsis

Atomic and Molecular Physics

Measuring Many-Body Entanglement

Read More »

Related Articles

Synopsis: Transition to Superlubricity in 2D
Fluid Dynamics

Synopsis: Transition to Superlubricity in 2D

Studying particles sliding over a 2D potential lattice, researchers have observed a phase transition between a frictional regime and a frictionless, “superlubric” regime Read More »

Synopsis: Two-Face Dipole
Optics

Synopsis: Two-Face Dipole

A proposed dipole source of electromagnetic waves can selectively couple its emission into either of two neighboring waveguides. Read More »

Synopsis: X-Ray Absorption Spectroscopy on a Tabletop
Optics

Synopsis: X-Ray Absorption Spectroscopy on a Tabletop

A laser-based setup can be used to perform x-ray spectroscopy with a precision rivaling that of experiments at large-scale synchrotron facilities. Read More »

More Articles