In a development that brings space-based power generation systems a step closer to reality, researchers from the Japan Aerospace Exploration Agency (JAXA) and the Osaka University Institute of Laser Engineering have developed groundbreaking new technology for converting sunlight into laser beams.

Relying on plates made from a special ceramic material containing chromium (which absorbs the sunlight) and neodymium (which efficiently converts sunlight to laser light), the newly developed lasers demonstrated an impressive 42% solar-to-laser energy conversion efficiency, outperforming previous technology by a factor of four.

The researchers say the new laser technology will play a key role in JAXA’s “Space Solar Power Systems” (SSPS) project, which aims to put space-based power systems in orbit by the year 2030. By mounting the system on a satellite in stationary orbit 36,000 km (22,400 mi.) above the equator, sunlight would be collected and converted into a powerful laser beam, which would then be aimed at a terrestrial power station and used to generate electricity or produce hydrogen.

Unlike earthbound solar power stations, which are subject to night-time darkness and cloudy conditions, JAXA’s SSPS will be able to make use of solar energy 24 hours a day. With slight improvements in the solar-to-laser conversion efficiency and by incorporating solar collectors measuring 100 to 200 meters long, a single satellite will be able to match the output of a 1-gigawatt nuclear power plant, the researchers say. One can only hope these lasers never fall into the wrong hands.

The results of the research were announced at a meeting of the Japan Society of Applied Physics that began on September 4 in Sapporo.

[Source: Asahi]

In 1926, Kenjiro Takayanagi, known as the “father of Japanese television,” transmitted the image of a katakana character (?) to a TV receiver built with a cathode ray tube, signaling the birth of the world’s first all-electronic television. Last week, in a symbolic gesture over 80 years later, researchers from Japan’s National Institute of Advanced Industrial Science and Technology (AIST), Burton Inc. and Hamamatsu Photonics K.K. displayed the same katakana character using a 3D projector that generates moving images in mid-air.

The 3D projector, which was first unveiled in February 2006 but has seen some recent improvements, uses focused laser beams to create flashpoint “pixels” in mid-air. The pixels are generated as the focused lasers heat the oxygen and nitrogen molecules floating in the air, causing them to spark in a phenomenon known as plasma emission. By rapidly moving these flashpoints in a controlled fashion, the projector creates a three-dimensional image that appears to float in empty space.

The projector’s recent upgrades include an improved 3D scanning system that boosts laser accuracy, as well as a system of high-intensity solid-state femtosecond lasers recently developed by Hamamatsu Photonics. The new lasers, which unleash 100-billion-watt pulses (0.1-terawatt peak output) of light every 10-trillionths of a second (100 femtoseconds), improve image smoothness and boost the resolution to 1,000 pixels per second. In addition, image brightness and contrast can be controlled by regulating the number of pulses fired at each point in space.

The researchers say these improvements bring us one step closer to realizing the dream of 3DTV, but considering it took eight decades for Takayanagi’s primitive 40-scan-line television to evolve into our present-day HDTV, we might have a while to wait.

[Source: AIST press release]

For people looking to liven up the formal rigamarole surrounding the exchange of business cards in Japan, Arigatou Co., Ltd., a company specializing in the sale of laser-etched food products, offers “Taberu Me” edible business cards printed on peanuts.

Taberu Me cards are created using Arigatou’s high-grade CO2 laser engraver nicknamed “Shiawase-kun,” which can etch up to 700 characters per second on hard organic materials like beans, nuts, rice and pasta and which has been optimized to print clean-looking logos, names and telephone numbers on the irregular surfaces of peanut shells.

As for the product name, Taberu means “eat” and Me could either be an abbreviation of meishi (”business card”) or “me” in English, in which case Taberu Me would be saying “Eat me” — a message you probably don’t want to convey to your new business partner at the first meeting. Regardless, a set of 150 Taberu Me cards costs 5,800 yen (around $50), which is mere peanuts considering the lasting impression you will make on your new counterparts.

[Link: Taberu Me via Gizmodo Japan]

Hitachi has successfully trial manufactured a lightweight, portable brain scanner that enables users to keep tabs on their mental activity during the course of their daily lives. The system, which consists of a 400 gram (14 oz) headset and a 630 gram (1 lb 6 oz) controller worn on the waist, is the result of Hitachi’s efforts to transform the brain scanner into a familiar everyday item that anyone can use.

The rechargeable battery-operated mind reader relies on Hitachi’s so-called “optical topography” technology, which interprets mental activity based on subtle changes in the brain’s blood flow. Because blood flow increases to areas of the brain where neurons are firing (to supply glucose and oxygen to the tissue), changes in hemoglobin concentrations are an important index by which to measure brain activity. To measure these hemoglobin concentrations in real time, eight small surface-emitting lasers embedded in the headset fire harmless near-infrared rays into the brain and the headset’s photodiode sensors convert the reflected light into electrical signals, which are relayed to the controller.

The real-time brain data can either be stored in Flash memory or sent via wifi to a computer for instant analysis and display. A single computer can support up to 24 mind readers at a time, allowing multiple users to monitor brain activity while communicating or engaging in group activities.

In addition to health and medical applications, Hitachi foresees uses for the personal mind reader in fields such as psychology, education and marketing. Although it is unclear what neuromarketing applications the company has in mind, it is pretty clear that access to real-time customer brain data would provide marketers with a better understanding of how and why shoppers make their purchasing decisions. One can also imagine interactive campaigns that, for example, ask customers to think positive thoughts about a certain product in exchange for discount coupons or the chance to win a prize.

The technology could also be used in new forms of entertainment such as “mind gaming,” where the player’s physical brain activity becomes a part of game play. It is also feasible to integrate the brain scanner with a remote control brain-machine interface that would allow users to operate electronic devices with their minds.

Hitachi has yet to determine when the personal mind reader will be made commercially available.

[Source: Tech-On!]

Digital Information Development (DID) has developed a highly portable virtual piano that is played with a keyboard consisting of projected laser beams.

The box-shaped device measures about 10 x 3 x 3 cm (4 x 1 x 1 in.) and weighs about 100 grams (3.5 oz.). Using a red semiconductor laser module and holographic optical element, the device projects a 25-key 2-octave keyboard onto the surface in front of it (black surfaces don’t work because they absorb the light). A CMOS camera module and infrared (invisible) red semiconductor laser module detect which keys are touched, and the corresponding notes are emitted from speakers built into the device. Chords can also be played, and DID claims it is technically possible to reproduce weighted notes (but presumably not with this version).

The keyboard has 3 other voices in addition to piano — organ, pipe organ and harpsichord. It is scheduled for release in Japan in November 2006 and is expected to cost around 15,000 yen (US$130).

DID says that a virtual 88-key grand piano can be created by increasing the size of the device.

[Source: Yomiuri Shimbun]

Researchers at Kyoto University have developed new semiconductor laser technology that allows the shape of beams to be tailored freely and that can output beams up to 10 times more compact than existing beams – a development that could lead to a tenfold increase in the storage capacity of optical discs. Research results were published in the June 22 edition of British science journal Nature.

The Kyoto University group, led by professor Susumu Noda, worked with Kyoto-based Rohm Co., Ltd. and the Japan Science and Technology Agency (JST) to engineer layers of photonic crystals consisting of tens of thousands of small holes, which were incorporated into 0.5 mm x 0.5 mm semiconductor chips. The photonic crystal layer works as an optical resonator, with each individual hole functioning as a tiny mirror that causes the light to resonate in the semiconductor until it is emitted as laser light. The result is a laser beam with a diameter up to 10 times smaller and with properties different from those of conventional semiconductor lasers.

According to the researchers, these new semiconductor lasers were able to produce a range of beam patterns while maintaining stable single-mode oscillation. The ability to control the oscillation direction of light in this way could lead to the development of compact lasers capable of producing diverse beam patterns on demand, such as hollow beams (with cross-sections that look like donuts), concentric hollow beams (donuts within donuts), and other shapes that have heretofore been impossible to form.

Controlling the oscillation direction of light also means that lasers can be focused into ultra-thin beams, enabling a tenfold increase in the density of data storage on discs without changing the wavelength of the laser. Using blue lasers such as those used in Blu-ray disc technology could lead to DVDs with hundreds of gigabytes of capacity.

Potential applications are not limited to ultra-high density storage media. Ultra-thin, hollow beams could be used as “tweezers” for trapping and moving microscopic particles, which could bring a new level of precision to molecular-level processing and fabrication. Hidemi Takasu, Rohm’s research director, says, “In addition to seeing our research applied to next-generation DVD technology, we hope it can be applied to imaging technology that uses lasers to project precise images directly onto the human retina.”

[Sources: Yomiuri Shimbun, Kyoto Shimbun, JST press release]

In an annual rite of spring, scientists in Japan carefully monitor the atmosphere for yellow dust. Also known as Asian dust, yellow sand or yellow wind, yellow dust is a phenomenon in which strong seasonal winds kick up giant clouds of fine Gobi desert sand. The dust clouds travel eastward, affecting air quality in China, Korea and Japan, and occasionally the continental US.

Japan’s Meteorological Research Institute uses a remote sensing technique known as aerosol LIDAR (light detection and ranging) to monitor the status of the atmosphere and measure phenomena such as yellow dust. When weather conditions permit, a green laser beam is shot into the night sky from a small prefab structure belonging to the institute. The laser light is partly backscattered as it strikes particles floating as high as 40 km (25 miles) in the atmosphere, and the strength and timing of the reflected signals allows observers on the ground to analyze the particle content of the air.

On the night of April 17, the Omaezaki weather station in Shizuoka prefecture confirmed the presence of yellow dust in the atmosphere.

[Source: Yomiuri Shimbun]

Scientists using special laser technology have crafted a pair of mini-spectacles (2 mm) and placed them on the head of a housefly.

This photograph is part of a science photo exhibit being held in Munich, Germany from March 20 to 25.

[Source: Jiji via Yahoo! Japan]

UPDATE 29/Mar/2006: Needcoffee.com posted a nice story about the origins of this photo.

UPDATE 31/Mar/2006: An old Micreon press release explains the rest.

An unmanned aircraft powered by a ground-based laser was demonstrated at Osaka Dome on March 7. The aircraft is the work of a Kinki University research team led by Professor Nobuki Kawashima (aeronautical engineering). The researchers expect the aircraft to be used for gathering information in the event of a disaster.

The aircraft measures 78 cm (30 in.) long, weighs 800 grams (1.8 lbs.), and has wings like a kite. A disc-shaped solar panel attached underneath powers the propeller when struck by a ground-based laser.

A battery powered the aircraft’s propeller at takeoff, but once it reached an altitude of about 50 meters (165 feet) — near the ceiling of the dome — the aircraft switched to laser-powered flight. The laser remained on target (error less than 1 cm) throughout the 20-minute flight around the dome. Observers say the aircraft looked like a kite flying on a string of light.

Flight time with this technology is unlimited as long as the laser can reach the aircraft, as opposed to a 5-minute flight time when powered by battery. Researchers envision this type of aircraft being used to get an understanding of areas devastated by earthquake or flood, or to serve as flying communication relay stations. Leisure-related applications are also possible.

“We would like to extend the tracking distance and increase the size of the aircraft,” says Kawashima. “Hopefully we can make it commercially available in about 2 or 3 years.”

[Source: Asahi Shimbun]

Japan’s National Institute of Advanced Industrial Science and Technology (AIST) has developed a device that uses lasers to project real three-dimensional images in mid-air. The institute unveiled the device on February 7 in a demonstration that showed off the device’s ability to project three-dimensional shapes of white light.

AIST developed the projector with the cooperation of Keio University and Burton Inc. (Kawasaki, Japan). Until now, projected three-dimensional imagery has been “artificial” — optical illusions that appear 3D due to the parallax difference between the eyes of the observer. Prolonged viewing of this conventional sort of 3D imagery can cause physical discomfort.

The newly developed device, however, creates “real” 3D images by using laser light, which is focused through a lens at points in space above the device, to create plasma emissions from the nitrogen and oxygen in the air at the point of focus. Because plasma emission continues for a short period of time, the device is able to create 3D images by moving the point of focus.

At the demonstration, bursts of laser light were emitted 100 times per second to form shapes in the air up to 50 cm above the device. Heat from the laser caused the air to expand, producing a crackling sound that resembled a series of tiny explosions.

At the moment, the distance at which the device can project images is limited to between 2 and 3 meters. Improved laser technology will enable images to be projected at greater distances and with more color, so we may soon see 3D images floating above our city skylines.

The chief scientist at AIST’s Photonics Research Institute says, “We believe this technology may eventually be used in applications ranging from pyrotechnics to outdoor advertising.”

[Sources: Mainichi Shimbun, AIST press release, Burton Inc.]

UPDATE 1: The English translation of the press release is here.

UPDATE 2 (Aug 16, 2007): New and improved 3D projector