Kanagawa and Tokyo, Japan--Scientists at QD Laser, Fujitsu Laboratories Limited, and the Institute for Nano Quantum Information Electronics, the University of Tokyo have created what they say is the world's first 1.3-µm-emitting semiconductor laser that operates at temperatures over 200°C (previous semiconductor lasers have been limited to temperatures no higher than 175°C). With quantum dots as the active material, these new lasers could find use in oil and gas exploration, where temperatures often far exceed the boiling point of water.
Working high-temperature quantum-dot lasers require a high density and uniformity of quantum dots. Along with acheving this, the researchers also improved quantum-dot manufacturing technology, reducing the degree of quantum-dot dispersion and enhancing uniformity up to a density of 60 billion dots per cm2 (see figure). Eight layers of these high-density and uniform quantum dots were stacked to create the laser. Under rigorous test conditions, the researchers confirmed that these lasers could emit at temperatures of up to 220°C; more than 2 mW of optical output was obtained at 200°C.
QD Laser (Tokyo, Japan) will commercialize these lasers.
QD Laser is exhibiting the new lasers at Laser World of Photonics in Munich, Germany (Booth # B1-310), held May 23–26, 2011. Details of the technology are being presented at the European Conference on Lasers and Electro-Optics and the Quantum Electronics and Laser Science Conference (CLEO/Europe--EQEC 2011), held from May 22, 2011 in Munich.
A portion of this research was funded by the Special Coordination Funds for Promoting Science and Technology MEXT (Ministry of Education, Culture, Sports, Science and Technology).
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