A step toward optical transistors?
As demand for computing and communication capacity surges, the global communication infrastructure struggles to keep pace, since the light signals transmitted through fiber-optic lines must still be processed electronically, creating a bottleneck in telecommunications networks.
While the idea of developing an optical transistor to get around this problem is alluring to scientists and engineers, it has also remained an elusive vision, despite years of experiments with various approaches. Now, 缅北强奸 researchers have taken a significant, early step toward this goal by showing a new way to control light in the semiconductor nanocrystals known as 鈥渜uantum dots.鈥�
In results published online recently in the journal听Nano Letters, PhD candidate Jonathan Saari, Prof. Patanjali (Pat) Kambhampati and colleagues in 缅北强奸鈥檚 Department of Chemistry show that all-optical modulation and basic Boolean logic functionality 鈥� key steps in the processing and generation of signals 鈥� can be achieved by using laser-pulse inputs to manipulate the quantum mechanical state of a semiconductor nanocrystal.
鈥淥ur findings show that these nanocrystals can form a completely new platform for optical logic,鈥� says Saari. 鈥淲e鈥檙e still at the nascent stages, but this could mark a significant step toward optical transistors.鈥�
Quantum dots already are used in applications ranging from photovoltaics, to light-emitting diodes and lasers, to biological imaging. The Kambhampati group鈥檚 latest findings point toward an important new area of potential impact, based on the ability of these nanocrystals to modulate light in an optical gating scheme.
鈥淭hese results demonstrate the proof of the concept,鈥� Kambhampati says. 鈥淣ow we are working to extend these results to integrated devices, and to generate more complex gates in hopes of making a true optical transistor.鈥�
The findings build on a 2009 paper by Kambhampati鈥檚 research group in听Physical Review Letters.听That work revealed previously unobserved light-amplification properties unique to quantum dots, which are nanometer-sized spheroids with size-dependent optical properties, such as absorption and photoluminescence.
The research for the听Nano Letters听article was supported by the Canada Foundation for Innovation, the Natural Sciences and Engineering Research Council of Canada, and the Fonds de recherche du Qu茅bec - Nature et technologies.
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