A Microscope that Sees without Looking

Nov 21, 2005

A new type of microscope overcomes some of the limitations of optical imaging techniques by looking at how samples affect a tiny antenna, rather than looking at the sample itself.

Most optical microscopes create images by collecting photons reflected from a surface. But when samples get very small or have tiny features, the limitations of optics kick in and prevent the imaging of objects smaller than a micron or so across.

Instead of shining a light on a sample, a team of Swiss and German researchers have found that they can take pictures of a small sample by illuminating a tiny, gold antenna placed near a surface. The antenna emits different signals depending on the sample structure. It's much like sweeping a metal detector over the ground to map out the location of a buried pipe – the rising and falling pitch of the metal detector results because the hidden metal changes the way the detector circuit reacts.

Conventional optical microscopy, on the other hand, is more like radar, which would locate a buried pipe by bouncing radio waves off of it. The microscope in the new study consists of an antenna made from a single particle of gold, 100 nanometers in diameter or smaller, mounted on the tip of a glass fiber that is scanned over the sample at a height of 5 to 10 nanometers.

The system provides detail of structures as small as a few hundred nanometers across, but the researchers believe the technique has the potential to be refined to image features a hundred times smaller.

Original work:

Optical Microscopy via Spectral Modifications of a Nanoantenna
T. Kalkbrenner et al.
Physical Review Letters 95, 200801 (2005)
link.aps.org/abstract/PRL/v95/e200801

Source: American Physical Society

Explore further: New insights found in black hole collisions

add to favorites email to friend print save as pdf

Related Stories

Shiny quantum dots brighten future of solar cells

Apr 14, 2014

(Phys.org) —A house window that doubles as a solar panel could be on the horizon, thanks to recent quantum-dot work by Los Alamos National Laboratory researchers in collaboration with scientists from University ...

Nanotube coating helps shrink mass spectrometers

Mar 25, 2014

Nanotechnology is advancing tools likened to Star Trek's "tricorder" that perform on-the-spot chemical analysis for a range of applications including medical testing, explosives detection and food safety.

Recommended for you

X-rays probe LHC for cause of short circuit

Mar 27, 2015

The LHC has now transitioned from powering tests to the machine checkout phase. This phase involves the full-scale tests of all systems in preparation for beam. Early last Saturday morning, during the ramp-down, ...

New insights found in black hole collisions

Mar 27, 2015

New research provides revelations about the most energetic event in the universe—the merging of two spinning, orbiting black holes into a much larger black hole.

Swimming algae offer insights into living fluid dynamics

Mar 27, 2015

None of us would be alive if sperm cells didn't know how to swim, or if the cilia in our lungs couldn't prevent fluid buildup. But we know very little about the dynamics of so-called "living fluids," those ...

First glimpse inside a macroscopic quantum state

Mar 27, 2015

In a recent study published in Physical Review Letters, the research group led by ICREA Prof at ICFO Morgan Mitchell has detected, for the first time, entanglement among individual photon pairs in a beam ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.