Long-distance communication increasingly relies on networks of fiber-optic cables that carry data encoded in nimble beams of light. Conventional computer circuits, however, still use relatively sluggish electronic circuits to process this data.
Hong Cai of the A*STAR Institute of Microelectronics in Singapore and her co-workers have now developed a device that could help computers reach light speed. Their tiny mechanical system can switch a light signal on or off extremely quickly, potentially enabling all-optical computing and simplifying the interface between electronic and optical networks1. “All-optical devices could enable a large number of components to be housed on a single chip,” says Cai.
Various optical switching technologies already exist, including microelectromechanical systems (MEMS). These switches, however, take microseconds to flip from one state to another, far too slow for a computer application. Cai’s device is a much smaller nanoelectromechanical system (NEMS) that can switch in billionths of a second, with virtually no data loss.
“NEMS optical switches offer the potential for fast switching speed, low optical loss and low power consumption. And, they are easily integrated in large-scale arrays without complex packaging techniques,” says Cai.
The researchers etched their device from a thin sheet of silicon, forming a flexible ring 60 micrometers wide that is connected to a central pillar by four thin spokes. Two channels running through the underlying silicon skim past opposite edges of the ring; they act as waveguides for two beams of light. These channels pass no closer than 200 nanometers from the ring (see image).
When light carrying a signal passes through one of the channels, the light’s electromagnetic field establishes resonant oscillations around the ring. This draws energy from the beam and prevents the data from travelling any further — the switch is effectively ‘off’.
To flip the switch, a low-power beam of 10 milliwatts traveling along the other channel establishes a similar resonance that slightly warps the ring, bending its edges downwards by just a few nanometers. This warping motion changes the resonant frequency of the ring, preventing it from coupling to the signal beam and allowing the data to continue unimpeded. Switching the signal on took just 43.5 nanoseconds, and the researchers observed a large difference in signal light output between the ‘on’ and ‘off’ states.
“As such, a low-power optical signal can be used to modulate a high-power optical signal at high speed,” says Cai. Her team is now working on integrating the devices into circuits.
The A*STAR-affiliated researchers contributing to this research are from the Institute of Microelectronics
Cai, H., Dong, B., Tao, J. F., Ding, L., Tsai, J. M. et al. A nanoelectromechanical systems optical switch driven by optical gradient force. Applied Physics Letters 102, 023103 (2013).
Cloud technology: Dynamic certificates make cloud service providers more secure
15.01.2018 | Technische Universität München
New discovery could improve brain-like memory and computing
10.01.2018 | University of Minnesota
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy