Quantum dot semiconductor laser technology wins Green IT Award
About the Green IT Award The Green IT Award was established to honor contributions to the development, expansion, and application of IT equipment, services, and solutions that reduce society's energy consumption, with the aim of increasing the prevalence of green IT and bringing about a society that both preserves the environment and achieves economic growth. Product Recognized Quantum dot (QD) lasers are state-of-the-art semiconductor lasers which are formed using quantum dots(1) on the surface of a semiconductor substrate and which fully leverage the so-called quantum effect(2). QD lasers feature revolutionary advantages over other types of semiconductor lasers, including lower power consumption, superior temperature stability, and higher temperature tolerance. The lasers will make it possible to conserve energy as energy usage increases with the expansion of the Internet and improvements in the capabilities of ICT equipment. The technology was proposed in 1982 by Professor Yasuhiko Arakawa, Director of the Institute for Nano Quantum Information Electronics, The University of Tokyo(3), and was subsequently developed through an industrial-academic collaboration between Fujitsu and the University of Tokyo. QD Laser, Inc. was established to commercialize the technology and the company has begun the world's first mass production of QD lasers for use in optical communications. The Green IT Award recognized the advanced capabilities of this device technology, as well as its wide range of potential medium- to long-term applications. At the same time, it also praised the creative thinking that led researchers to bring about innovation by leveraging the principles underlying the device, as well as the achievements resulting from this innovation and the 15-year-long industrial-academic collaboration. Notes 1 Quantum dot:A grain-like structure measuring between a few nanometers to several tens of nanometers in size. 2 Quantum effect:Atoms that are confined to a narrow region (on the scale of a few nanometers to several tens of nanometers, 1 nanometer = 1.0 × 10-9 meters) can only assume discrete energy levels. The quantum dot laser technology leverages this property to prevent the flow of excess electrical current, allowing only the minimal necessary current, thereby making it possible to decrease the laser's energy loss and enhance its temperature stability. 3 Y. Arakawa et al.:Multidimensional quantum well laser and temperature dependence of its threshold current. Appl. Phys. Lett., Vol.40, p.939-941(1982)
