Nanoplasmonic Bubble Lens Controls Focus and Direction of Light

Credit: Tony Jun Huang, Penn State

Scientists have developed a reconfigurable plasmofluidic lens using nanoplasmonics that can control light waves at the nanoscale. The nanoscale light beam is modulated by surface plasmon polaritons (SPP) which are short electromagnetic waves. The light wave is controlled by the bubble lens which can control the focus and direction of light.

Nanoplasmonics is a new field of science that deals with the behavior of metal particles at the nanoscale and its optical properties. At the nanoscale, light or electromagnetic waves approaches half the size of its wavelength. At this level, the electrical field of light displaces the metal's electrons producing an oscillating field or what is called a surface plasmon. By using certain metal nanoparticles such as gold or silver and manipulating its size and shape, the surface plasmons can be modulated.

Ancient stained glass windows (which contains gold and silver particles) use nanoplasmonic properties to attain its deep vibrant colors when light passes through it.

Currently, manipulating and reconfiguring the focus and direction of these light waves have been difficult. But with the development of reconfigurable plasmofluidic lens, which are essentially tiny bubbles, scientists have found a way to control, switch, and modulate light.

Applications for nanoplasmonics can be found in photovoltaics and optical plasmonic systems. In photovoltaic systems, plasmons can be used to modify the opto-electronic properties for fast photo-detectors and effective photocells. With optical plasmonic systems, devices can be developed that manipulate the optical properties which may lead to the development of inexpensive, fast and small active optical elements.

ESO Installs Supercomputer At ALMA Facility - The ALMA Correlator

The ALMA correlator

One of the fastest supercomuter, the ALMA correlator, has been fully installed and tested at the ALMA astronomical facility in Chile. With over 134 million processors and performance up to 17 quadrillion operations per second, the ALMA correlator is one of the fastest supercomputers in existence today.

The Atacama Large Millimeter /submillimeter Array (ALMA) is a space telescope located on the Chajnantor plateau in the Chilean Andes. It has 66 high-precision antennas, spread over distances of up to 16 kilometres. The facility is partially operational and will be fully completed by March 2013.

ALMA studies light emitted by some of the coldest objects in space. Since these objects emit light that is hardly detected, the ALMA looks at wavelengths between infrared light and radio waves. This is known as millimeter and submillimeter radiation. The telescope can detect light emitted by objects that are a few degrees above absolute zero.

The space telescope can help astronomers study the chemical and physical conditions in molecular clouds where stars are produced. These clouds are made up of dense gas and dust which are dark and obscured in visible light, much like clouds in the sky are. By detecting the light emitted in near infrared, ALMA can detect and collect data from these objects.

With the installation of the ALMA correlator, it will increase the sensitivity and image quality of its observation of outer space.

Transformational Optics Metamaterial Leads To Development Of Improved Invisibility Cloak

A new metamaterial based on transformational optics has been engineered that can successfully split light waves around an object. This can lead to advancements in fiber optics as well as in the development of a more advanced cloaking device or as it is popularly known, an invisibility cloak.

Nanophotonics Allow Color Manipulation A Few Atoms Wide With Opaque Objects

Nanophotonics is the study that has anything to do with light at the nanoscale level. The nanoscale level is usually around 1-100 nanometers (nm); a nanometer is one billionth of a meter.

Using nanophotonics, researchers at Harvard have discovered that color can be manipulated at the nanoscale even with opaque objects. These kind of objects are impenetrable by light and are believed cannot exhibit thin-film interference effects.

Thin film interference effects happen when light waves interfere with each other as they pass through a medium and are reflected back out. As they are reflected back, some colors come out brighter while others are lost. An example of this would be rainbow like colors reflected back from an oily puddle on the street.

MIT News: Bending Light To Cloak Objects Lead To Better Electron Transfer For Thermoelectric Devices

A new approach that allows objects to become “invisible” has now been applied to an entirely different area: letting particles “hide” from passing electrons, which could lead to more efficient thermoelectric devices and new kinds of electronics.

Diagram shows the 'probability flux' of electrons, a representation of the paths of electrons as they pass through an 'invisible' nanoparticle. While the paths are bent as they enter the particle, they are subsequently bent back so that they re-emerge from the other side on the same trajectory they started with — just as if the particle wasn't there.
Image courtesy Bolin Liao et al.

The concept — developed by MIT graduate student Bolin Liao, former postdoc Mona Zebarjadi (now an assistant professor at Rutgers University), research scientist Keivan Esfarjani, and mechanical engineering professor Gang Chen — is described in a paper in the journal Physical Review Letters.