Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Optics: Nanotechnology’s benefits brought into focus

16.08.2013
Mathematical modeling confirms that a nanometer-scale device that can concentrate light into a tiny spot improves optical sensing

Conventional lenses, made of shaped glass, are limited in how precisely they can redirect beams of incoming light and make them meet at a point. Now, a team led by Zhengtong Liu at the A*STAR Institute of High Performance Computing, Singapore, has proposed a novel approach to ‘superlens’ systems that can surpass this classical limit of focusing light.

The team used numerical modeling to develop the design. Concentrating radiation into a smaller volume in this way enhances the interaction between light and matter, and thus the concept could prove useful in highly sensitive sensors of the future.

Light is a type of wave. Unlike the rise and fall in sea water at a beach, however, a light wave consists of oscillating electric and magnetic fields. The wavelength — the distance a wave travels in one oscillation cycle — imposes a limit on the minimum size to which light can be focused. However, this limit does not apply over small distances that are comparable to the wavelength, which is known as the near-field regime.

The researchers designed a silver nanostructure embedded in glass. Their device combined two separate elements. One component was a nanoantenna — similar to the radio-frequency antennas used to detect television-carrying signals, but reduced in size to match the wavelength of optical radiation. The other component was a superlens made of a thin slab of silver. The purpose of the superlens was to move the light detected by the nanoantenna into an imaging plane. “Using nanoantennas to concentrate light is not a new idea,” says Liu. “But by adding a superlens to translate the concentrated spot of light, we can overcome limitations imposed by the optical properties of the material.”

Liu and co-workers mathematically modeled the optical response of this device to an incoming beam of red light. They then altered the dimensions of the structure to maximize the enhancement in electric field. In this way, they were able to show that a 20-nanometer-thick superlens, separated by 34 nanometers from an antenna made of two silver ellipses, could increase the electric field of light by a factor of 250 (see image).

Confining light into these super intense ‘hot-spots’ could prove a boon for optical detection systems. “Our concept is targeted at biomedical and chemical sensing applications,” explains Liu. “The next step is to seek collaboration opportunities to actually make the sensor and test it in the field.”

The A*STAR-affiliated researchers contributing to this research are from the Institute of High Performance Computing

Journal information

Liu, Z., Li, E., Shalaev, V. M. & Kildishev, A. V. Near field enhancement in silver nanoantenna-superlens systems. Applied Physics Letters 101, 021109 (2012).

ResearchSEA Account for A*STAR | Research asia research news
Further information:
http://www.a-star.edu.sg
http://www.researchsea.com

More articles from Physics and Astronomy:

nachricht Water without windows: Capturing water vapor inside an electron microscope
13.12.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University

nachricht Columbia engineers create artificial graphene in a nanofabricated semiconductor structure
13.12.2017 | Columbia University School of Engineering and Applied Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

A whole-body approach to understanding chemosensory cells

13.12.2017 | Health and Medicine

Water without windows: Capturing water vapor inside an electron microscope

13.12.2017 | Physics and Astronomy

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>