Laboratory Equipment

Nanostructured Metamaterial Changes Properties of Light

Researchers are edging toward the creation of new optical technologies using “nanostructured metamaterials” capable of ultra-efficient transmission of light, with potential applications including advanced solar cells and quantum computing.

The metamaterial - layers of silver and titanium oxide and tiny components called quantum dots - dramatically changes the properties of light. The light becomes “hyperbolic,” which increases the output of light from the quantum dots. Such materials could find applications in solar cells, light emitting diodes and quantum information processing far more powerful than today’s computers.

Read more: http://www.laboratoryequipment.com/news-Nanostructured-Metamaterial-Changes-Properties-of-Light-052512.aspx

Scientists Uncover a Photosynthetic Puzzle

Quantum physics and plant biology seem like two branches of science that could not be more different, but surprisingly they may in fact be intimately tied. Researchers at the Argonne National Laboratory and the Notre Dame Radiation Laboratory at the Univ. of Notre Dame used ultrafast spectroscopy to see what happens at the subatomic level during the very first stage of photosynthesis.

“If you think of photosynthesis as a marathon, we’re getting a snapshot of what a runner looks like just as he leaves the blocks,” says Argonne biochemist David Tiede. “We’re seeing the potential for a much more fundamental interaction than a lot of people previously considered.”

Read more: http://www.laboratoryequipment.com/news-scientists-uncover-a-photosynthetic-puzzle-052312.aspx

Microscope Sees Blood Cells Through the Skin

Blood tests convey vital medical information, but the sight of a needle often causes anxiety and results take time. A new device developed by a team of researchers in Israel, however, can reveal much the same information as traditional blood test in real-time, simply by shining a light through the skin. This optical instrument, no bigger than a breadbox, is able to provide high-resolution images of blood coursing through our veins without the need for harsh and short-lived fluorescent dyes.

Read more: http://www.laboratoryequipment.com/news-Rainbow-Light-Enables-New-Microscope-to-Look-Through-Skin-052212.aspx

Reflective Coating Makes Device Invisible

It may not be intuitive, but a coating of reflective metal can actually make something less visible, engineers at Stanford and UPenn have shown. They have created an invisible, light-detecting device that can “see without being seen.”

At the heart of the device are silicon nanowires covered by a thin cap of gold. By adjusting the ratio of metal to silicon – a technique the engineers refer to as tuning the geometries – they capitalize on favorable nanoscale physics in which the reflected light from the two materials cancel each other to make the device invisible.

Read more: http://www.laboratoryequipment.com/news-Researchers-Use-Plasmonics-to-Make-an-Invisible-Photodetector-052212.aspx

Light Improves Moods, Cognitive Abilities

EPFL scientists have proven that light intensity influences people’s cognitive performance and how alert they feel, and that these positive effects last until early evening.

Tests conducted in EPFL’s Solar Energy and Building Physics Laboratory (LESO) have confirmed the hypothesis that light influences people’s subjective feeling of sleepiness. The research team, led by Mirjam Münch, also showed that the effects of light exposure last until the early evening, and that light intensity has an impact on cognitive mechanisms. The results of this research were recently published in the journal Behavioral Neuroscience.

Read more: http://www.laboratoryequipment.com/news-Light-Improves-Moods-Cognitive-Abilities-051512.aspx

Quantum Dots Brighten the Future of Lighting

With the age of the incandescent light bulb fading rapidly, the holy grail of the lighting industry is to develop a highly efficient form of solid-state lighting that produces high quality white light.

One of the few alternative technologies that produce pure white light is white-light quantum dots. These are ultra-small fluorescent beads of cadmium selenide that can convert the blue light produced by an LED into a warm white light with a spectrum similar to that of incandescent light. (By contrast, compact fluorescent tubes and most white-light LEDs emit a combination of monochromatic colors that simulate white light).

Read more: http://www.laboratoryequipment.com/news-Improved-Quantum-Dots-May-Be-Lighting-the-Future-050912.aspx

Butterflies Inspire Low-Energy Light Displays

The bright colors of a rainbow or a peacock are produced by the reflection and interference of light in transparent periodic structures, producing what is called a structural color. These colors are very bright and change according to the viewing angle. On the other hand, the wings of a morpho-butterfly also have structural colors but are predominantly blue over a wide range of angles. This is because the unique structure of the morpho-butterfly’s wings contains both order and chaos.

Prof. Shin Jung Hoon’s team from the Department of Physics and the Graduate School of Nanoscience and Technology at KAIST produced a display that mimics the structure of the morpho-butterfly’s wings using glass beads.

Read more: http://www.laboratoryequipment.com/news-Butterflies-Inspire-Low-Energy-Light-Displays-050812.aspx

Green, Blue LEDs Provide Higher Efficiency

Like a coffee enthusiast who struggles to get a buzz from that third cup of morning joe, light-emitting diodes (LEDs) seem to reach a point where more electricity no longer imparts the same kick and productivity levels-off. Now a team of researchers from California and Japan has devised a new design for green and blue LEDs that avoids much of this vexing efficiency droop. The findings will be presented at the Conference on Lasers and Electro-Optics (CLEO: 2012), taking place May 6-11 in San Jose, Calif.

By changing the orientation of the crystal structure in semiconductor films, the team created LEDs with high efficiency and extremely low droop. Droop, which is a dramatic drop in efficiency at high currents, is one of the main problems limiting the growth of the solid-state lighting market.

Read more: http://www.laboratoryequipment.com/news-Efficient-LEDs-Could-Lead-to-Affordable-Lighting-050112.aspx

Device Rids Buses of Dangerous Pathogens

The best place to enjoy a breath of fresh air may be a city bus, if Rice Univ. students have their way. A team of graduating seniors has created a system for public transit that would continually clear the air of pathogens that can lead to tuberculosis (TB), flu and pneumonia.

The CityBusters – Joseph Spinella, Jerry Lue, Sundeep Mandava, Grace Ching and Shidong Chen, all seniors – have installed a $500 device on a METRO bus in Houston that has proven effective at killing 99.8 percent of the pathogens that circulate through the air-filtering system. The device, called FluProof, incorporates high-powered ultraviolet lamps that sterilize the air on the fly.

Read more: http://www.laboratoryequipment.com/news-Device-Rids-Busses-of-Dangerous-Pathogens-043012.aspx

Coupled Lasers Can Switch Each Other Off

Two lamps are brighter than one. This simple truism does not necessarily apply to lasers, as a team of scientists, led by the Vienna Univ. of Technology found out. When one laser is shining and next to it another laser is turned on gradually, complex interactions between the two lasers can lead to a total shutdown and no light is emitted anymore. For technologies connecting the fields of electronics and photonics, this result may be very important. The new findings have now been published in the journal Physical Review Letters.

Read more: http://www.laboratoryequipment.com/news-Coupled-Lasers-Can-Switch-Each-Other-Off-042612.aspx

LED-Like Solar Cells Break Efficiency Record

To produce the maximum amount of energy, solar cells are designed to absorb as much light from the Sun as possible. Now researchers from the Univ. of California, Berkeley, have suggested — and demonstrated — a counterintuitive concept: solar cells should be designed to be more like LEDs, able to emit light as well as absorb it. The Berkeley team will present its findings at the Conference on Lasers and Electro Optics (CLEO: 2012), to be held May 6-11 in San Jose, Calif.

“What we demonstrated is that the better a solar cell is at emitting photons, the higher its voltage and the greater the efficiency it can produce,” says Eli Yablonovitch, principal researcher and UC Berkeley professor of electrical engineering.

Read more: http://www.laboratoryequipment.com/news-LED-Like-Solar-Cells-Break-Efficiency-Record-042012.aspx