Novel semiconductor lasers can be used for space exploration

http://www.goodchinabrand.com/49062400070en.html

According to foreign media reports, the University of California researchers using a new method of manufacturing a semiconductor laser work at terahertz frequencies. The semiconductor laser can be used to analyze the formation of stars and planets atmospheric composition.

In the electromagnetic spectrum, terahertz frequency range lies between microwaves and infrared. Terahertz wave can be detected without damaging the material to be analyzed under the premise of plastic, clothing, semiconductors and art materials, etc., it can also be used to analyze the stars the formation and composition of the planet's atmosphere.

Currently using visible vertical external cavity surface emitting laser (VECSEL) has been widely used to generate high-energy beam, but this technique is not applicable to previously terahertz frequency range. Associate Professor of the University of California, Los Angeles, led by electrical engineering Benjamin Williams ` Development of the first team in the terahertz frequency range of VECSEL. findings recently published in the (Applied Physics Letters) on.

In order to emit high-energy beam VECSEL terahertz frequency range, developed with the Williams team called a 'super-reflective front surface mirror' means VECSEL. This device is so named because it contains a large number of tiny by the array antenna coupled laser cavity consisting of, so that when the terahertz wave passes this array will 'see' not see the laser cavity, it will be reflected back, like being an ordinary mirror reflecting back the same.

'Taking over the material surface and the laser combine for the first time.' Williams said, this method only allows the laser in the THz frequency range of the output more power, but also a high-quality laser beam, and metamaterials It allows researchers to use laser beams to further designed to generate the desired polarization, shape and frequency.

A member of one of the research, first author Xu Luyao (phonetic) further explained: 'by super material surface as part of the outer chamber, we can not only improve the shape of the laser beam, but also through different external cavity design to a laser band to new features such as you can to maximize output power and efficiency of the laser. By using the stand-alone wire polarizer or filter as a second reflecting surface, we simply rotating polarizer. '

Japan tech to explore Jupiter moon

The Yomiuri Shimbun

http://the-japan-news.com/news/article/0002377117


The European Space Agency has decided to adopt for an exploration mission to Jupiter technology developed by a Japanese research institute for observing electromagnetic waves. The technology would be used to analyze the atmosphere and surface ice of Ganymede, one of Jupiter’s moons, and play an important role in searching for signs of life.

The ESA plans to launch the Jupiter Icy Moons Explorer (JUICE) in 2022 and have a probe arrive near the planet in 2030. The probe is to be equipped with technology for observing terahertz radiation (see below) that was developed by Yasuko Kasai, a specialist in Earth and planetary observation and a senior researcher at the National Institute of Information and Communications Technology (NICT), which is under the Internal Affairs and Communications Ministry.

This would be the first time for the technology, which detects faint electromagnetic waves emitted by various substances to determine their type and properties, to be used in planetary exploration.

Scientists from the ESA and NICT are expected to exchange written agreements on the matter this month.

JUICE is scheduled to spend about three years orbiting Jupiter and Ganymede, and will use NICT’s observation equipment and several other devices to investigate their origins and properties.

Ganymede is one of Jupiter’s 60 moons. With a radius of about 2,600 kilometers, it is the largest moon in the solar system. While smaller than Earth, which has a radius about 6,400 kilometers, it is larger than Mercury’s 2,400-kilometer radius.

The mission plans to observe Ganymede using terahertz radiation at altitudes ranging from 200 kilometers to 5,000 kilometers. The technology would be used to search for elements that are essential for life, including nitrogen, oxygen, carbon and phosphorus, as well as nitrous oxide, which indicates the possibility of life.

NICT’s terahertz radiation equipment features an antenna that is about 30 centimeters in diameter and weighs about 13 kilograms. At a cost of several hundred million yen, the technology is both compact and relatively cheap. According to NICT, equipment with similar capabilities but using microwaves and ultraviolet light would weigh about 500 kilograms, making it impossible to load onto the probe.

■ Terahertz radiation

A form of electromagnetic wave with a frequency between that of radio waves and light. Substances emit terahertz radiation at fixed frequencies, so by analyzing differences in the frequencies, the presence of certain substances in the atmosphere or on the ground’s surface can be investigated.Speech