Quantum Dots To Increase Optic Fiber Bandwidth By 7 to 10 Times
- Quantum Dot Light Source
Quantum dots are tiny particles made of semiconductor crystals, and they are being used by the Photonic Network Research Institute of NICT to increase the bandwidth of optical communication systems by approximately 7-10 times, allowing for building a high capacity and a high flexibility data transmission system using a wide optical frequency range that combines a light source and a photonic crystal fiber.
The high quality quantum dots NICT have created are very stable, have a high optical frequency, and by using them as the light source or amplifier in optical systems, they can be tuned to operate in optical frequency bands about 70 Thz wide, approximately seven times wider than the 10 Thz of frequency bands currently in use.
"We've been conducting R&D on quantum dots itself for quite a long time. But we've now created a new technology called "Sandwiched sub-nano separator structure", which is unique to NICT. And by using that, we've finally completed this light source technology. Usually when you fabricate quantum dots, you grow crystalline quantum dot particles, in nanometer size, on the semiconductor surface. But this time, we've formed a very thin layer, less than one nanometer thick, between the surface and the dots. By adding just this nanometer layer, we've be able to form high-quality quantum dots, without aggregation structures, at very high density."
The development and construction of this prototype was undertaken by NICT in collaboration with university students and optics companies Koshin Kogaku and Sevensix.
As well as for use in optical communication systems, this new wavelength band effectively permeates human skin, so these quantum dots are expected to be used in bioimaging and medical sensing, such as high resolution imaging and measurement of new molecules in cells.
"We're currently working with Koshin Kogaku Co., Ltd. and Sevensix Inc., which collaborated in developing the quantum dot light source, to consider market development, through samples and preliminary products. We intend to loan demonstration equipment, for experimental purposes, to universities and research institutes. Japan has extremely strong capabilities in nanotechnology and we'd like to bring those capabilities together in a way that boosts Japan's economy."