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: Straining After Quantum Dots
Semiconductor Physics

Synopsis: Straining After Quantum Dots

The positions of quantum dots inside a microstructure can be determined by monitoring how an applied strain affects the dots’ photoluminescence.   Read More »

Viewpoint: A New Twist on Relativistic Electron Vortices
Nanophysics

Viewpoint: A New Twist on Relativistic Electron Vortices

Two studies explore the properties of vortices formed by electrons that travel at relativistic speeds. Read More »

Synopsis: A Neat Way to Slow Down Light
Optics

Synopsis: A Neat Way to Slow Down Light

A new technique slows down light in a crystal by simply shining a laser on it and varying an applied voltage. Read More »

More Articles