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 Temperature-controlled fiber-optic light source with liquid core
20.06.2018 | Leibniz-Institut für Photonische Technologien e. V.

nachricht New material for splitting water
19.06.2018 | American Institute of Physics

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: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

What are the effects of coral reef marine protected areas?

21.06.2018 | Life Sciences

The Janus head of the South Asian monsoon

21.06.2018 | Earth Sciences

The world's tiniest first responders

21.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>