Most materials from which on-chip lasers can be built are not compatible with silicon substrates, but these researchers has high hopes for their atomically thin (just 0.7 nanometers thick) laser can be integrated onto standard silicon chips.
"Today we are using a tungsten photonics cavity sandwiched between layers of selenium, but we hope to achieve the same results with silicon nitride in the future," said EE professor Arka Majumdar, who did the work with fellow professor Xiaodong Xum and his doctoral candidate assistant, Sanfeng Wu.
Caption: An ultra-thin semiconductor using just three atom thick material stretches across a photonic cavity to emit light. (Source: U of Washington)
As the thinnest semiconductor today, according to Majumdar and Wu, it is super energy efficient and can be electro-modulated with a signal of only 27 nanowatts, making it ideal for on-chip communications. The new material has also excited other groups who are busy building light-emitting diodes (LEDs), solar cells and even transistors using this new semiconductor.
Creating a nano laser out from it required building an optical-confinement cavity to intensify the light, fashioned from a single layer of the tungsten-based material. The gain of the material can be carefully tuned and it uses the standard frequencies for on-chip, between chip and between board communications. Next the group will carefully characterize the material as well as experiment possibly improving it further by using silicon nitride.
Other researchers contributing to the work include John Schaibley of the University of Washington and Liefeng Feng of the University of Washington and Tianjin University in China, Sonia Buckley and Jelena Vuckovic of Stanford, Jiaqiang Yan and David G. Mandrus of Oak Ridge National Laboratory and the University of Tennessee, Fariba Hatami of Humboldt University in Berlin and Wang Yao of the University of Hong Kong.
Funding was provided by the Air Force Office of Scientific Research, the National Science Foundation, the state of Washington’s Clean Energy Institute, the Presidential Early Award for Scientists and Engineers administered through the Office of Naval Research, the U.S. Department of Energy, and the European Commission.
— R. Colin Johnson, Advanced Technology Editor, EE Times