/ News
Researchers observe and control light wakes for the first time
This is an artistic rendition of the superluminal running wave of charge that excites the surface plasmon wakes. Credit: Daniel Wintz, Patrice Genevet, and Antonio Ambrosio.
When a duck paddles across a pond or a supersonic plane flies through the sky, it leaves a wake in its path. Wakes occur whenever something is traveling through a medium faster than the waves it creates -- in the duck's case water waves, in the plane's case shock waves, otherwise known as sonic booms.
Wakes can exist wherever there are waves, even if those waves are light. While nothing travels faster than the speed of light in a vacuum, light isn't always in a vacuum. It is possible for something to move faster than the phase velocity of light in a medium or material and generate a wake. The most famous example of this is Cherenkov radiation, wakes produced as electrical charges travel through liquids faster than the phase velocity of light, emitting a glowing blue wake.
For the first time, Harvard researchers have created similar wakes of light-like waves moving on a metallic surface, called surface plasmons, and demonstrated that they can be controlled and steered. The discovery, published today in the journal Nature Nanotechnology, was made in the lab of Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at the Harvard John A. Paulson School of Engineering and Applied Science (SEAS).
"The ability to control light is a powerful one," said Capasso. "Our understanding of optics on the macroscale has led to holograms, Google Glass and LEDs, just to name a few technologies. Nano-optics is a major part of the future of nanotechnology and this research furthers our ability to control and harness the power of light on the nanoscale."
The creation and control of surface plasmon wakes could lead to new types of plasmonic couplers and lenses that could create two-dimensional holograms or focus light at the nanoscale.
Surface plasmons are confined to the surface of a metal. In order to create wakes through them, Capasso's team designed a faster-than-light running wave of charge along a one-dimensional metamaterial -- like a powerboat speeding across a lake.
The metamaterial, a nanostructure of rotated slits etched into a gold film, changes the phase of the surface plasmons generated at each slit relative to each other, increasing the velocity of the running wave. The nanostructure also acts like the boat's rudder, allowing the wakes to be steered by controlling the speed of the running wave.
The team discovered that the angle of incidence of the light shining onto the metamaterial provides an additional measure of control and using polarized light can even reverse the direction of the wake relative to the running wave -- like a wake traveling in the opposite direction of a boat.
"Being able to control and manipulate light at scales much smaller than the wavelength of the light is very difficult," said Daniel Wintz, a lead author of the paper and graduate student in the Capasso lab. "It's important that we not only observed these wakes but found multiple ways to control and steer them."
The observation itself was challenging, as "surface plasmons are not visible to the eye or cameras," said co-lead author Antonio Ambrosio of SEAS and the Italian Research Council (CNR). "In order to view the wakes, we used an experimental technique that forces plasmons from the surface, collects them via fiber optics and records the image."
This work could represent a new testbed for wake physics across a variety of disciplines. "This research addresses a particularly elegant and innovative problem in physics which connects different physical phenomena, from water wakes to sonic booms, and Cherenkov radiation," said Patrice Genevet, a lead author, formerly of SEAS, currently affiliated with the Singapore Institute of Manufacturing Technology.
This paper was co-authored by Alan She, of SEAS and Romain Blanchard, of SEAS and Eos Photonics.
This research was supported by the National Science Foundation and the Air Force Office of Scientific Research.
Story Source:
The above post is reprinted from materials provided by Harvard University. Note: Materials may be edited for content and length.
Journal Reference:
- Patrice Genevet, Daniel Wintz, Antonio Ambrosio, Alan She, Romain Blanchard & Federico Capasso. Controlled steering of Cherenkov surface plasmon wakes with a one-dimensional metamaterial. Nature Nanotechnology, 2015 DOI: 10.1038/nnano.2015.137
Source: http://www.sciencedaily.com/releases/2015/07/150706123733.htm
/ About us
Founded by Russian entrepreneur Dmitry Itskov in February 2011 with the participation of leading Russian specialists in the field of neural interfaces, robotics, artificial organs and systems.
The main goals of the 2045 Initiative: the creation and realization of a new strategy for the development of humanity which meets global civilization challenges; the creation of optimale conditions promoting the spiritual enlightenment of humanity; and the realization of a new futuristic reality based on 5 principles: high spirituality, high culture, high ethics, high science and high technologies.
The main science mega-project of the 2045 Initiative aims to create technologies enabling the transfer of a individual’s personality to a more advanced non-biological carrier, and extending life, including to the point of immortality. We devote particular attention to enabling the fullest possible dialogue between the world’s major spiritual traditions, science and society.
A large-scale transformation of humanity, comparable to some of the major spiritual and sci-tech revolutions in history, will require a new strategy. We believe this to be necessary to overcome existing crises, which threaten our planetary habitat and the continued existence of humanity as a species. With the 2045 Initiative, we hope to realize a new strategy for humanity's development, and in so doing, create a more productive, fulfilling, and satisfying future.
The "2045" team is working towards creating an international research center where leading scientists will be engaged in research and development in the fields of anthropomorphic robotics, living systems modeling and brain and consciousness modeling with the goal of transferring one’s individual consciousness to an artificial carrier and achieving cybernetic immortality.
An annual congress "The Global Future 2045" is organized by the Initiative to give platform for discussing mankind's evolutionary strategy based on technologies of cybernetic immortality as well as the possible impact of such technologies on global society, politics and economies of the future.
Future prospects of "2045" Initiative for society
2015-2020
The emergence and widespread use of affordable android "avatars" controlled by a "brain-computer" interface. Coupled with related technologies “avatars’ will give people a number of new features: ability to work in dangerous environments, perform rescue operations, travel in extreme situations etc.
Avatar components will be used in medicine for the rehabilitation of fully or partially disabled patients giving them prosthetic limbs or recover lost senses.
2020-2025
Creation of an autonomous life-support system for the human brain linked to a robot, ‘avatar’, will save people whose body is completely worn out or irreversibly damaged. Any patient with an intact brain will be able to return to a fully functioning bodily life. Such technologies will greatly enlarge the possibility of hybrid bio-electronic devices, thus creating a new IT revolution and will make all kinds of superimpositions of electronic and biological systems possible.
2030-2035
Creation of a computer model of the brain and human consciousness with the subsequent development of means to transfer individual consciousness onto an artificial carrier. This development will profoundly change the world, it will not only give everyone the possibility of cybernetic immortality but will also create a friendly artificial intelligence, expand human capabilities and provide opportunities for ordinary people to restore or modify their own brain multiple times. The final result at this stage can be a real revolution in the understanding of human nature that will completely change the human and technical prospects for humanity.
2045
This is the time when substance-independent minds will receive new bodies with capacities far exceeding those of ordinary humans. A new era for humanity will arrive! Changes will occur in all spheres of human activity – energy generation, transportation, politics, medicine, psychology, sciences, and so on.
Today it is hard to imagine a future when bodies consisting of nanorobots will become affordable and capable of taking any form. It is also hard to imagine body holograms featuring controlled matter. One thing is clear however: humanity, for the first time in its history, will make a fully managed evolutionary transition and eventually become a new species. Moreover, prerequisites for a large-scale expansion into outer space will be created as well.
Key elements of the project in the future
• International social movement
• social network immortal.me
• charitable foundation "Global Future 2045" (Foundation 2045)
• scientific research centre "Immortality"
• business incubator
• University of "Immortality"
• annual award for contribution to the realization of the project of "Immortality”.
/ Follow us at:
/ Contact:
For additional information, partnerships and sponsorship, contact:
info@2045.com
Media requesting information and interviews, contact PR@2045.com
LinkedIn
LiveJournal
Google
Twitter
Facebook
Я.ру
ВКонтакте
Mail.ru