National Institute of Standards and Technology (NIST) Achieves Record Quantum Teleportation Distance

Researchers at the National Institute of Standards and Technology (NIST) have "teleported" or transferred quantum information carried in light particles over 100 kilometers (km) of optical fiber, four times farther than the previous record.

The experiment confirmed that quantum communication is feasible over long distances in fiber. Other research groups have teleported quantum information over longer distances in free space, but the ability to do so over conventional fiber-optic lines offers more flexibility for network design. The experiment used photons to transfer the information.

A photon is a single particle of light. It is an elementary particle that exhibits both particle and wave properties; wave–particle duality. The study of photons usually falls under but not limited to quantum mechanics.

Photons have many real world applications. Solar energy cells use photons to convert sunlight to energy. Some systems like the Single Photon Emission Computed Tomography (SPECT) use it to generate images. The mass of photons was one of the factors that lead researchers at CERN in the Large Hadron Collider to help discover the Higgs Particle. Even in science fiction, the photon torpedo or photon gun is part of a spaceship's arsenal.

New Signal Amplification, Cycling Excitation Process (CEP), Opens Up New Generation of Electronic Systems

Researchers from the University of California, San Diego has discovered a new signal amplification process called CEP or Cycling Excitation Process.

CEP can amplify photocurrents at a much lower voltage and noise than current existing methods.

Current semiconductor devices use photodetectors and low-noise electronic amplifiers to convert optical signals into electronic signals with amplification to enable information detection and processing. The UC San Diego team found a more efficient method by modifying the p/n junction, a boundary or interface between two types of semiconductor material inside a single crystal of semiconductor.

CEP can be used in devices and semiconductors which opens up a myriad of possibilities in the semiconductor industry; communication and imaging devices with superior sensitivity can be produced at a low cost.

New types of transistors and circuits can also be produced that furthers the scope of applications past optical detection.

Blue Liquid Laser Light Discovered

A new inorganic material using boron hydrides or boranes in a solution that emits laser light in the blue spectral region has been discovered. The discovery was done by researchers at the Spanish National Research Council (CSIC), Spain's largest public institution dedicated to research and the third largest in Europe.

The newly discovered laser material has a higher degrading resistance making it last longer. Because of this. the borane solution is superior compared to other laser materials commercially available in the blue laser range.

The high resistance to degradation also addresses occupational and environmental impact of these solvents since they are replaced less in the commercial setting.

Liquid laser materials emit laser light similar to its organic rare earth materials like rubies. The light emitted by these have very high energy and are coherent.

Coherent light travels in a straight line without scattering. In comparison, sunlight is incoherent light is it is scattered and not focused on one area or region. A flashlight is also incoherent light and travels in a "cone".

The team of researchers plan to synthesize the boranes solution to emit at other wavelengths (colors), as this would lead to practical applications in dermatology such as tattoo, scar or acne removal, as well as treatments of vascular lesions.

The work is published in Nature Communications

Low Cost, High Definition Transparent Display Developed Through Nanotechnology

Researchers from MIT and Harvard departments of Physics, and the US Army Edgewood Chemical Biological Center have teamed up to develop a low cost, scalable, and high resolution display system using nanoparticles that can be displayed on transparent glass.

The system works by applying silver nanoparticles on a transparent glass screen. Like a filter, this allows other colors to pass through leaving the color used by the laser projector to show up on the display. The nanoparticles interact with a single color and lets others go through just like regular glass.

As an example, the transparent display in the picture above shows the blue MIT logo on the glass screen but not on the three cups behind it. (Image credit: Chia Wei Hsu and Bo Zhen)

Applications for this technology are varied from flexible and scrollable displays, 3D transparent screens, and even peel-and-stick projection foils. Windows of buildings can be used for advertising as it only entails applying the nanoparticle layer on it.

The transparent display is scalable allowing high definition images to come up even on large displays. It is even inexpensive. The demo unit only cost less than ten dollars to develop.

Linac Coherent Light Source Experiments On Chemical Reactions Lead To Clean Energy Development

New experiments at the Linac Coherent Light Source, an X-ray free-electron laser, took an unprecedented look at the way carbon monoxide molecules react with the surface of a catalyst in real time.
Credit: Greg Stewart / SLAC National Accelerator Laboratory

Ongoing experiments at the Linac Coherent Light Source Facility aimed at observing chemical reactions within catalysts may lead into better and more efficient clean energy technologies.

The Linac Coherent Light Source (LCLS) is a free electron laser facility located at the Stanford Linear Accelerator Center (SLAC). A free electron laser (FEL) is a laser that has the same optical properties of a conventional laser but uses a different principle in forming the laser beam. Free electron lasers use an electron beam which moves freely through a magnetic structure. Conventional lasers use electrons in an excited bound atomic or molecular state.

The LCLS uses ultra-fast x-ray pulses 10⁹ times brighter than traditional synchotron (a type of particle accelerator) x-rays. The x-rays are used to image objects at an atomic level. The wavelength generated by the LCLS is close to the width of an atom which allows a very detailed image at a level thought to be impossible.

The X-ray pulses are used much like flashes from a high-speed strobe light, enabling scientists to take stop-motion pictures of atoms and molecules in motion, shedding light on the fundamental processes of chemistry, technology, and life itself.

Overcoming Heisenberg's Uncertainty Principle In Polarization of Light Through The Direct Measurement Technique

Weak measurement: as light goes through a birefringent crystal the horizontally and vertically polarized components of light spread out in space, but an overlap between the two components remains when they emerge. In a “strong” measurement the two components would be fully separated.
Credit: Credit: Jonathan Leach

Researchers have developed a new technique that overcomes Heisenberg's Uncertainty Principle in measuring the polarization states of light.

The Uncertainty Principle was developed by a German theoretical physicist, Werner Karl Heisenberg. Known also as Heisenberg's Principle, the Uncertainty Principle states that the position and velocity cannot both be accurately known or measured at the same time. One may know the exact position but not the velocity and vice-versa.

This principle is one of the most famous underlying principle of quantum mechanics. In classical physics, it is easy to determine the exact momentum and position of a passing car at a specific time. But in quantum mechanics, where objects studied are at atomic and sub-atomic sizes, measuring both of these variables accurately at the same time becomes a problem.

This can be observed through the embedded video which shows MIT Professor Walter Lewin demonstrating the uncertainty principle with laser light. In it, he shows that as the position of the photons in the laser becomes more and more accurate, the direction of the laser light becomes wider and wider making it impossible to gauge its direction.

Recently, researchers believe they have a developed a technique that works around this bizarre behavior. This could lead to using light to encode information that can be read by quantum computers.

Graphene Shows Potential To Be Efficient Photovoltaic Material In Light Detection and Energy Harvest

Graphene research has shown that the material can be used in the development of efficient solar photovoltaic cells.

Much has been written and discussed about graphene. It has opened up a whole litany of advanced applications that it has been described as "The Wonder Material".

One particular property of graphene that many scientists have been focusing on is how electrons behave and interact with graphene. Graphene, being only one atom thick, allows electron to move much more freely along its surface. The electrons travel through the graphene sheet as if they carry no mass, as fast as just one hundredth that of the speed of light. This makes graphene a great conductor, better than even copper.

Also, since graphene is just one atom thick, diodes, transistors, and other electronic components can be developed on a single-layered device architecture. By using nano-scale electronic channels and tailoring the geometrical symmetry, devices can be operated on at very high speeds of up to 1.5 Terahertz (1,500 GHz). This allows for the development of high speed electronics for various applications and devices.

Researchers have discovered a new property of graphene that allows it to convert a single absorbed photon into multiple electrons. This could open up research into the development of efficient solar cells.

Photon Detector Reads In Four States With An Error Rate Four Times Lower Than Previous Devices

Researchers at the The Joint Quantum Institute (JQI) established a new standard for reading quantum information in detecting photons with a minimum of uncertainty. By using a network of photon detectors with feedback instead of a single passive detector, the JQI photodetector beats the quantum limit by a factor of 4.

They reported their findings in the journal, Nature Photonics.

PHOTONS

A photon is a single particle of light. It is an elementary particle that exhibits both particle and wave properties; wave–particle duality. The study of photons usually falls under but not limited to quantum mechanics.

Photons have many real world applications. Solar energy cells use photons to convert sunlight to energy. Some systems like the Single Photon Emission Computed Tomography (SPECT) use it to generate images. The mass of photons was one of the factors that lead researchers at CERN in the Large Hadron Collider to help discover the Higgs Particle. Even in science fiction, the photon torpedo or photon gun is part of a spaceship's arsenal.

It is even being studied as a data carrier in quantum computer processors.

PHOTON DETECTORS

The most basic device used in studying photons is the photon detector. It is used to count how many photon particles there are in a beam of light. A photon detector has some surface that absorbs photons and produces some effect (current, voltage) proportional to the number of photons absorbed.

But as with most detectors, there will be "noise" or factors that affect its reading of the data. Especially in quantum mechanics where some fundamental principles are still unclear (like wave-particle duality).

Silicon Based Photovoltaic (Solar Cell) Fiber Leads To Electricity Generating Fabrics

Optical fiber, thinner than human hair, has been developed with photovoltaic properties which may give rise to fabric that can generate electricity. The fiber which is silicon based acts on the principle of solar cells that convert sunlight into electrical energy.

According to Neils Bohr, using the model of a hydrogen atom, an electron (-) orbits a stationary proton (+) in certain fixed orbits held by an electric force . When an electron jumps to a higher or lower orbit (called a quantum leap), it expends or absorbs energy (in the form of light).

Energy is needed for the electron to jump to a higher orbit where it has higher energy levels. When the electron moves to an orbit closer to the proton, energy is released.

Using this principle, a simplified explanation of how a silicon solar cell works would be that when a silicon solar cell absorbs light from the sun, the electron jumps from a higher orbit to a lower orbit which in turn gives off electrical energy.

A more detailed explanation is featured in the embedded video.

For years, the solar cell has been used to harness the suns energy to produce electrical energy. As technology evolves, solar cells have become much more efficient and cost effective in the alternative-energy industry. In 2011, solar power accounted for a total US$147 billion in investments and generated around 69.7 Gigawatts of energy globally.

Physicists Devise A Way Using Squeezed Light In Measuring Distance

Non-classical light is light that has characteristics described through quantum mechanics and not using real world or classical properties. One type of non-classical light is squeezed light.

Squeezed light put simply is light that is manipulated in the quantum level through the generation of photons. Since the number of photons in a beam of light is random, squeezed light is generated with a steady number of photons in the beam. It can be said that the number of photons travelling in the light beam from squeezed light is a constant.

The result of using squeezed light is that quantum noise (random fluctuations in the wavelength) is reduced significantly. This makes measuring distance and targets more precise. Also with less noise, transmitted signals are clearer.

Since the photons are constant in squeezed light with minimal quantum noise, any fluctuations recorded are from outside source and not a result of that noise.

Applications for squeezed light range from using it for communication (fiber optics), measuring distance, and detecting gravitational waves. It is also being used in quantum cryptography where code keys are transmitted via squeezed light.

Light squeezed on a quantum scale

An international team of physicists has pushed the boundaries on ultra-precise measurement by harnessing quantum light waves in a new way.

It is one thing to be able to measure spectacularly small distances using "squeezed" light, but it is now possible to do this even while the target is moving around.

An Australian-Japanese research collaboration made the breakthrough in an experiment conducted at the University of Tokyo, the results of which have been published in an article, "Quantum-enhanced optical phase tracking" in the prestigious journal, Science.

Advances in MASER Technology Aligns It With LASER Technology

In each frame, a molecule in the upper level of the MASER transition (that is, in the high energy, excited state) is indicated by a large red circle, while one in the lower level (low energy state) is indicated by a small blue circle. (a) All of the molecules are in the upper state and a photon of wavelength l (shown in green) is incident from the left. (b) The photon l stimulates emission from the first molecule, so there are now two photons of wavelength l, in phase. (c) These photons stimulate emission from the next two molecules, resulting in four photons of wavelength l. (d) The process continues with another doubling of the number of photons.
Credit: Stanford University/M. L. Kutner, "Astronomy: A Physical Perspective", John Wiley & Sons, Inc. 1987

MASER is an acronym for Microwave Amplification by Stimulation Emission of Radiation. It is a device that produces coherent electromagnetic waves through amplification by stimulated emission. Coherent waves are two or more waves that generate waves at the same time, having the same frequency, amplitude, and phase.

During the development of the MASER, it was found that masers emit EM waves which are in the microwave and radio frequencies across a broader band of the electromagnetic spectrum. To maintain the accuracy of the acronym, it was suggested that the letter "M" stand for molecular rather than microwave.

A LASER is a type of MASER that works with photons at a higher frequency in the ultraviolet or visible light spectrum. In 1957, with the development of the optical coherent oscillator, the LASER was first called an optical maser. It eventually was called a LASER (Light Amplification by Stimulated Emission of Radiation), the name coined by Gordon Gould in 1957.

It was Albert Einstein who proposed the principle of stimulated emission in which the MASER was based. Einstein proposed that when atoms are induced into an excited energy state, these can amplify radiation at the proper frequency. By putting such an amplifying medium in a resonant cavity, feedback is created that can produce coherent radiation.

MASER power comes out of the cold

Scientists demonstrate, for the time, a solid-state "MASER" capable of operating at room temperature, paving the way for its widespread adoption – as reported today in the journal Nature.

MASER stands for Microwave Amplification by Stimulated Emission of Radiation. Devices based on this process (and known by the same acronym) were developed by scientists more than 50 years ago, before the first LASERs were invented. Instead of creating intense beams of light, as in the case of LASERs, MASERs deliver a concentrated beam of microwaves.

Conventional MASER technology works by amplifying microwaves using hard inorganic crystals such as ruby, this process is known as "masing". However, the MASER has had little technological impact compared to the LASER because getting it to work has always required extreme conditions that are difficult to produce; either extremely low pressures, supplied by special vacuum chambers and pumps, or freezing conditions at temperatures close to absolute zero ( -273.15°C), supplied by special refrigerators. To make matters worse, the application of strong magnetic fields has often also been necessary, requiring large magnets.

Now, the team from the National Physical Laboratory (NPL) and Imperial College London have demonstrated masing in a solid-state device working in air at room temperature with no applied magnetic field. Today's breakthrough means that the cost to manufacture and operate MASERs could be dramatically reduced, which could lead to them becoming as widely used as LASER technology.

The researchers suggest that room-temperature MASERs could be used to make more sensitive medical instruments for scanning patients, improved chemical sensors for remotely detecting explosives; lower-noise read-out mechanisms for quantum computers and better radio telescopes for potentially detecting life on other planets.

Linac Coherent Light Source (LCLS) - World's Most Powerful Laser That Can Be Controlled With Nanoscale Precision

To create a precise X-ray band and make the Linac Coherent Light Source even more “laser-like,” researchers installed this chamber with a slice of diamond crystal. The new hardware sits halfway down the 130-meter bank of magnets where the X-rays are generated.
Credit: Photo by Matt Beardsley, SLAC National Accelerator Laboratory

Light waves that are in phase with each other is called coherent light. Two waves are called coherent when the crests (highest part) and the troughs (lowest part) of each wave are aligned with each other.

An example of coherent light are light emitted by lasers. The light is focused and as can be observed with a laser pointer, travel in a straight line without any scattering.

Sunlight is an example of incoherent light. It is scattered and not focused on one area or region as a laser can. Light from a regular flashlight since it travels in a "cone" is also incoherent light.

World's most powerful X-ray laser beam refined to scalpel precision

With a thin sliver of diamond, scientists at the U.S. Department of Energy's (DOE) SLAC National Accelerator Laboratory have transformed the Linac Coherent Light Source (LCLS) into an even more precise tool for exploring the nanoworld. The improvements yield laser pulses focused to higher intensity in a much narrower band of X-ray wavelengths, and may enable experiments that have never before been possible.

In a process called "self-seeding," the diamond filters the laser beam to a single X-ray color, which is then amplified. Like trading a hatchet for a scalpel, the advance will give researchers more control in studying and manipulating matter at the atomic level and will deliver sharper images of materials, molecules and chemical reactions.

Part of the SLAC team who worked on self-seeding is shown alongside the hardware in the LCLS Undulator Hall. They are (from left to right) John Amann, Henrik Loos, Jerry Hastings and Jim Welch.
Credit: Photo by Matt Beardsley, SLAC National Accelerator Laboratory

"The more control you have, the finer the details you can see," said Jerry Hastings, a SLAC scientist and co-author on the research, published this week in Nature Photonics. "People have been talking about self-seeding for nearly 15 years. The method we incorporated at SLAC was proposed in 2010 by Gianluca Geloni, Vitali Kocharyan and Evgeni Saldin of the European XFEL and DESY research centers in Germany. When our team from SLAC and Argonne National Laboratory built it, we were surprised by how simple, robust and cost-effective the engineering turned out to be." Hastings added that laboratories around the world are already planning to incorporate this important advance into their own X-ray laser facilities.

Self-seeding has the potential to produce X-ray pulses with significantly higher intensity than the current LCLS performance. The increased intensity in each pulse could be used to probe deep into complex materials to help answer questions about exotic substances like high-temperature superconductors or intricate electronic states like those found in topological insulators.

World Smallest Semiconductor Laser - Breakthrough in Photonic Technology

Semiconductor lasers are eyed to be the next generation in laser technology. These lasters are compact, can be mass produced, easily integrated into applications, their properties are being improved constantly, they are becoming more and more powerful and efficient and they have found a widespread use as pumps for solid–state lasers.

The active medium of the laser is a semiconductor. This is similar to the ones found in an LED. The most common of this is formed from a p-n junction and powered by injected electric current. The former devices are sometimes referred to as injection laser diodes to distinguish them from optically pumped laser diodes.

The majority of the materials used by the semiconductor are based on a combination of elements in the third group of the Periodic Table (Aluminum (Al), Gallium (Ga), Indium (In)) and the fifth group (Nitrogen (N), Phosphorus (P), Arsenic (As), Antimony (Sb)). This group of elements are referred to as the III-V compounds. Examples include GaAs, AlGaAs, InGaAs and InGaAsP alloys. The cw laser emission wavelengths are normally within 630~1600 nm, but recently InGaN semiconductor lasers were found to generate cw 410 nm blue light at room temperature. The semiconductor lasers that can generate blue-green light uses materials which are the combination of elements of the second group (Cadmium (Cd) and Zinc (Zn)) and the sixth group (Sulfur (S), Selenium (SE)).

This is an illustration of the nanoscale semiconductor structure used for demonstrating the ultra-low-threshold nanolaser. A single nanorod is placed on a thin silver film (28 nm thick). The resonant electromagnetic field is concentrated at the 5-nm-thick silicon dioxide gap layer sandwiched by the semiconductor nanorod and the atomically smooth silver film.
Credit: (c)Science

World's smallest semiconductor laser created by University of Texas scientists

Physicists at The University of Texas at Austin, in collaboration with colleagues in Taiwan, have developed the world's smallest semiconductor laser, a breakthrough for emerging photonic technology with applications from computing to medicine.

The scientists report their efforts in this week's Science.

Miniaturization of semiconductor lasers is key for the development of faster, smaller and lower energy photon-based technologies, such as ultrafast computer chips; highly sensitive biosensors for detecting, treating and studying disease; and next-generation communication technologies.

Such photonic devices could use nanolasers to generate optical signals and transmit information, and have the potential to replace electronic circuits. But the size and performance of photonic devices have been restricted by what's known as the three-dimensional optical diffraction limit.

Graphene Promises New Levels of Technology in Photonic Chips

Graphene comes from graphite. Andre Geim and Konstantin Novoselov used the weak bond between the layers of graphite to isolate the three strong bonded carbon atoms and discovered graphene. Without the layer of weak bonds, graphene is a structure that is only one atom thick. Hence, it is a two dimensional object.

It is one of the thinnest and strongest material ever measured. The structure resembles chicken wire when viewed on the atomic scale.

Geim and Novoselov shared the 2010 the Nobel Prize for Physics for the discovery.

The two scientists in the March 2007 issue of Nature Materials defined graphene as "a flat monolayer of carbon atoms tightly packed into a two-dimensional (2D) honeycomb lattice, and is a basic building block for graphitic materials of all other dimensionalities. It can be wrapped up into 0D fullerenes, rolled into 1D nanotubes or stacked into 3D graphite."

Graphene is a material that has the potential to create foldaway mobile phones, wallpaper-thin lighting panels and the next generation of aircraft.

A graphene circuit can operate at high frequencies of up to 10GHz (10 billion cycles per second), and at temperatures of up to 127°C. It is the most transparent, strongest and most conductive material on Earth.

The unique properties of graphene can lead to a new paradigm for low power telecommunications

New research by Columbia Engineering demonstrates remarkable optical nonlinear behavior of graphene that may lead to broad applications in optical interconnects and low-power photonic integrated circuits. With the placement of a sheet of graphene just one-carbon-atom-thick, the researchers transformed the originally passive device into an active one that generated microwave photonic signals and performed parametric wavelength conversion at telecommunication wavelengths.

"We have been able to demonstrate and explain the strong nonlinear response from graphene, which is the key component in this new hybrid device," says Tingyi Gu, the study's lead author and a Ph.D. candidate in electrical engineering. "Showing the power-efficiency of this graphene-silicon hybrid photonic chip is an important step forward in building all-optical processing elements that are essential to faster, more efficient, modern telecommunications. And it was really exciting to explore the 'magic' of graphene's amazingly conductive properties and see how graphene can boost optical nonlinearity, a property required for the digital on/off two-state switching and memory."

The study, led by Chee Wei Wong, professor of mechanical engineering, director of the Center for Integrated Science and Engineering, and Solid-State Science and Engineering, will be published online in the Advance Online Publication on Nature Photonics's website on July 15 and in print in the August issue. The team of researchers from Columbia Engineering and the Institute of Microelectronics in Singapore are working together to investigate optical physics, material science, and device physics to develop next-generation optoelectronic elements.

Coherent Laser Light With Simultaneous Streams of Ultraviolet Light, X-Ray, and Wavelengths In Between Developed

This art represents an electron being ripped from an atom by a strong laser field, which stretches its quantum wave function over hundreds of atomic sizes. Just as electrons accelerated in an X-ray tube emit bremsstrahlung radiation, electrons accelerated by a laser can emit rainbows of coherent X-rays in a laser-like beam. X-ray light is "invisible to the human eye but is important for being able to 'see' the fine details and fastest motions of the nanoworld."
Credit: Tenio Popmintchev, JILA and University of Colorado at Boulder

Light is what allows the sense of sight. It is what the optic nerve registers to discern an object.

It is electromagnetic radiation (EMR) that comes in different wavelengths. Properties of light are intensity, propagation direction, frequency or wavelength spectrum, and polarization.

Light's speed in a vacuum is constant. It is 299,792,458 meters per second (also commonly known as the speed of light).

Light is emitted and absorbed in tiny "packets" or bundles called photons. Physics explains that photons manifest a duality in terms of properties. It behaves both as a wave and a particle. A particle can be compared to a marble while a wave is like a ripple formed when a pebble is thrown on a still lake. Light has been discovered to act both like a moving marble and a water ripple in various experiments. This property is referred to as the wave–particle duality. The study of light, known as optics, is an important research area in modern physics.

Coherent Light

Light waves that are in phase with each other is called coherent light. Two waves are called coherent when the crests (highest part) and the troughs (lowest part) of each wave are aligned with each other.

An example of coherent light are light emitted by lasers. The light is focused and as can be observed with a laser pointer, travel in a straight line without any scattering.

Sunlight is an example of incoherent light. It is scattered and not focused on one area or region as a laser can. Light from a regular flashlight since it travels in a "cone" is also incoherent light.

All the colors of a high-energy rainbow, in a tightly focused beam

For the first time, researchers have produced a coherent, laser-like, directed beam of light that simultaneously streams ultraviolet light, X-rays, and all wavelengths in between.

One of the few light sources to successfully produce a coherent beam that includes X-rays, this new technology is the first to do so using a setup that fits on a laboratory table.

An international team of researchers, led by engineers from the NSF Engineering Research Center (ERC) for EUV Science and Technology, reports their findings in the June 8, 2012, issue of Science.

New Imaging Technique Photoacoustic Tomography Ready For Clinical Use

The photoacoustic effect is when matter is measured by the effect of absorbed electromagnetic energy through acoustic detection. Based on this, photoacoustic imaging is done when non-ionizing laser pulses are delivered into biological tissues. Some of the delivered energy will be absorbed and converted into heat, leading to transient thermoelastic expansion and thus wideband ultrasonic emission. The generated ultrasonic waves are then detected by ultrasonic transducers to form images.

There are two types of photoacoustic imaging systems:

• Photoacoustic/Thermoacoustic computed tomography (PAT/TAT)
• Photoacoustic microscopy (PAM)

A PAT system usually employs an unfocused ultrasound detector to acquire the photoacoustic signals and generate the image. A PAM system, on the other hand, uses a spherically focused ultrasound detector with 2D point-by-point scanning and requires no reconstruction algorithm.

Photoacoustic Tomography (PAT), allows scientists to virtually peel away the top several inches of flesh to see what lies beneath.

The technique achieves this depth vision by an elegant marriage between light and sound, combining the high contrast due to light absorption by colored molecules such as hemoglobin or melanin with the spatial resolution of ultrasound.

Lihong V. Wang, PhD, the Gene K. Beare Distinguished Professor of Biomedical Engineering in the School of Engineering & Applied Science at Washington University in St. Louis, summarizes the state of the art in photoacoustic imaging in the March 23 issue of Science.

He is already working with physicians at the Washington University School of Medicine to move four applications of photoacoustic tomography into clinical trials. One is to visualize the sentinel lymph nodes that are important in breast cancer staging; a second to monitor early response to chemotherapy; a third to image melanomas; and the fourth to image the gastrointestinal tract.

Among the most exciting advances is the ability of photoacoustic tomography to reveal the use of oxygen by tissues, because excessive oxygen-burning (called hypermetabolism) is a hallmark of cancer.

In the early stages of cancer, there isn't much else to go on, Wang says, and so an early warning diagnostic test that does not require a contrast agent is potentially a game changer.

New Findings in Electron Density Lead to Better Imaging Devices and Applications

PRESS RELEASE: Findings point to advances in transistor and solar cell development

Kyoto, Japan -- Researchers at Kyoto University have announced a breakthrough with broad implications for semiconductor-based devices. The findings, announced in the December 20 issue of the journal Nature Communications, may lead to the development of ultra-high-speed transistors and high-efficiency photovoltaic cells.

Working with standard semiconductor material (gallium arsenide, GaAs), the team observed that exposing the sample to a terahertz (1,000 gigahertz) range electric field pulse caused an avalanche of electron-hole pairs (excitons) to burst forth. This single-cycle pulse, lasting merely a picosecond (10^-12 s), resulted in a 1,000-fold increase in exciton density compared with the initial state of the sample.

"The terahertz pulse exposes the sample to an intense 1 MV/cm^2 electric field," explains Hideki Hirori, team leader and Assistant Professor at Kyoto University's Institute for Integrated Cell-Material Sciences (iCeMS). "The resulting exciton avalanche can be confirmed by a bright, near-infrared luminescence, demonstrating a three-order of magnitude increase in the number of carriers."

Video: How Electron Microscopes Work

Research in Kyoto using terahertz waves is led by Professor Koichiro Tanaka, whose lab at the iCeMS pursues numerous applications including the development of new biological imaging technologies.

"Since terahertz waves are sensitive to water, our goal is to create a microscope that will allow us to look inside living cells in real time," says Prof. Tanaka. "These just-released results using semiconductors are an entirely different field of science, but they demonstrate the rich potential that lies in the study of terahertz waves

The Institute for Integrated Cell-Material Sciences (iCeMS) at Kyoto University in Japan aims to advance the integration of cell and material sciences -- both traditionally strong fields for the university -- in a uniquely innovative global research environment. The iCeMS combines the biosciences, chemistry, materials science, and physics to capture the potential power of stem cells (e.g., ES/iPS cells) and of mesoscopic sciences (e.g., porous coordination polymers). Such developments hold the promise of significant advances in medicine, pharmaceutical studies, the environment, and industry.

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Fabric Cleans Itself When Exposed to Sunlight

Scientists in China have developed a fabric that cleans itself of stains and bacteria when exposed to ordinary sunlight.

The scientists, Deyong Wu and Mingce Long, note that there are other self cleaning products already being developed but those use ultraviolet rays to self clean (see video). Their fabric uses ordinary sunlight.

Wu is from the School of Chemical and Environmental Engineering, Hubei University for Nationalities and Long is from the School of Environmental Science and Engineering, Shanghai Jiao Tong University.

The material uses a coating from a compound of titanium dioxide (TiO2). It is a cheap, nontoxic, highly efficient, stable, and ecologically friendly photocatalyst. This compound has been proved to be an excellent catalyst in the degradation of organic pollutants.

It won't be long until jeans, socks and other forms of clothing will be available that cleans and de-odorizes themselves when hung on a clothesline in the sun or draped on a balcony railing.

In chemical terms, photocatalysis is the acceleration of a photoreaction in the presence of a catalyst. In this case, sunlight triggers the self cleaning process of the fabric.

Video: UC Davis scientists compound that breaks down toxins and bacteria when exposed to light

TiO2 is already being used in self-cleaning windows, kitchen and bathroom tiles, odor-free socks and other products. It has also various uses in white paint, food, and sunscreen lotions. The compound breaks down dirt and kills microbes when exposed to some types of light.

Their science report describes cotton fabric coated with nanoparticles made from a compound of titanium dioxide and nitrogen. They show that fabric coated with the material removes an orange dye stain when exposed to sunlight. Further dispersing nanoparticles composed of silver and iodine accelerates the discoloration process. The coating remains intact after washing and drying.

The authors acknowledge funding from Donghua University and the National Natural Science Foundation of China.

The American Chemical Society is a non-profit organization chartered by the U.S. Congress. With more than 163,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

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Medical Treatments Through Photonics

The science of photonics includes investigation of the emission, transmission, amplification, detection, and modulation of light.

Just recently, scientists have developed a reconfigurable quantum photonic chip that can lead to the development of the quantum computer.

In the medical field, photonics (bio-medical optics or biophotonics) is used in the correction of poor eyesight, laser surgery, surgical endoscopy, and even tattoo removal. Photodynamic Therapy (PDT) is a form of photonics that is used to treat cancer. Other advanced applications for this technology involves facial plastic surgery, vascular birthmarks and malformations, breast cancer and treatment for a wide range of skin conditions, including acne, rosacea, psoriasis, birthmarks and skin cancers.

Imaging is also an important component of photonics. It can reconstruct an internal anomaly inside an organ or tissue by studying the light collected. The procedure involves scanning a sample with a light source while collecting light that exits the boundaries. The collected light is then matched with a model to find out the differences in light data.

Photonics is an ideal medium for treatment since light is non-invasive and non toxic. The limiting factor of photonics is that the light used for treatment cannot penetrate deeply. Current technology has light wavelengths usually reaching to about 1cm deep into the tissue. To achieve greater light penetration, hollow needles are used to get light into deeper tissues. Another way is using new high powered LED technology.

Video: Applying photonics to develop new medical treatments

The Beckman Laser Institute & Medical Clinic (BLI) at the University of California, Irvine (UCI), is one of the first dedicated center for research and treatment using lasers and light. The institute was founded in 1986 by Michael Berns and Arnold O. Beckman, to use lasers to study the basic biology of cells, and to apply the knowledge gained from those studies to understanding, diagnosing and treating disease.

BLI technologies and discoveries have had a major impact on cutaneous disease and treatment, cellular micromanipulation, intraluminal endoscopic imaging, functional imaging of cells and thick tissues, targeted phototherapies, and multi-modality imaging.