Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Northeastern University physicists become first to demonstrate flat lens imaging

02.12.2003


Researchers at Northeastern University today announced that they have been able to demonstrate the unique feature of imaging through a flat lens. Using the phenomenon of negative refraction through a novel photonic crystal, Northeastern physicists observed that a flat slab of such material behaves as a lens and focuses electromagnetic waves at microwave frequencies to produce a real image.



The research, published in tomorrow’s edition of the journal Nature, represents an important advance in the field of imaging. The lead author on the article, “Imaging by Flat Lens Using Negative Refraction,” is Srinivas Sridhar, Ph.D., from the department of physics and the Electronic Materials Institute at Northeastern. Contributors also include NU researchers Patanjali Parimi, Ph.D., Wentao Lu, Ph.D., and Plarenta Vodo.

"The significance of this research is that, for the first time, we have been able to image using a flat surface by employing a special material fabricated from a photonic crystal, which possesses a negative index of refraction,” said Sridhar. “Conventional materials, like glass or Teflon, possess positive indices of refraction and, in order to focus light or microwaves with them, you need to have a curved surface. When the concept of negative refraction emerged about 30 years ago, its most striking proposal was the notion that you could form an image using flat rather than curved surfaces. This research not only demonstrated this to be true but is a significant achievement toward the realization of several applications in imaging such as the concept of a ‘superlens’ with vastly improved power of resolution. ”


In the study, the researchers sought to expand upon a recent observation that in certain composite metamaterials, electromagnetic waves bend negatively. The key advance of the new research lies in the design of a new photonic crystal which is an artificial structure usually made out of dielectric or metal designed to control photons in a manner similar to the way a solid crystal controls electrons. Using a photonic crystal with suitable dispersion characteristics, in this case, an array of alumina rods, the researchers were able to achieve negative refraction at microwave frequencies.

This ability to demonstrate negative bending is significant because it allows considerable control over electromagnetic wave propagation, which could lead to new approaches to a variety of applications from microwave and optical frequencies. Some of the immediate applications of these negative index materials (also known as left-handed materials) are: sub-wavelength imaging by flat lenses, scanning photon tunneling microscopy, ultra high sensitive phase shifters, leaky wave antennas and optical switches based on negative refraction. Negative index materials could eventually be used to build new components for optical and microwave telecommunications equipment.

"The advantages of focusing by flat lenses are many,” said Sridhar. “Conventional optical systems have a single optical axis and limited aperture, both due to curved surfaces, and cannot focus light onto an area smaller than a square wavelength. In contrast, the present flat lens does not have a unique optical axis and is not restricted by the aperture size. One of the challenges of this knowledge will be trying to apply it to optical frequencies, which will require fabricating material using nanotechnology. We could potentially see a more immediate impact in the development of microwave antennas and other communications devices.”

Further information regarding negative refractive index materials and flat lens imaging can be found at the group website: sagar.physics.neu.edu. For a complete copy of the report, please call 617-373-7274.

Northeastern University, located in the heart of Boston, Massachusetts, is a world leader in cooperative education and recognized for its expert faculty and first-rate academic and research facilities. Through co-op, Northeastern undergraduates alternate semesters of full-time study with semesters of paid work in fields relevant to their professional interests and major, giving them nearly two years of professional experience upon graduation. The majority of Northeastern graduates receive a job offer from a co-op employer. Cited for excellence two years running by U.S. News & World Report, Northeastern was named a top college in the northeast by the Princeton Review 2003/04. In addition, Northeastern’s career services was awarded top honors by Kaplan Newsweek’s “Unofficial Insiders Guide to the 320 Most Interesting Colleges and Universities,” 2003 edition. For more information, please visit www.northeastern.edu.

Steve Sylven | Northeastern University
Further information:
http://www.nupr.neu.edu/11-03/nature.html

More articles from Physics and Astronomy:

nachricht NASA spacecraft investigate clues in radiation belts
28.03.2017 | NASA/Goddard Space Flight Center

nachricht Researchers create artificial materials atom-by-atom
28.03.2017 | Aalto University

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: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

NASA spacecraft investigate clues in radiation belts

28.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>