An electrical engineer at the University at Buffalo, who previously demonstrated experimentally the "rainbow trapping effect" -- a phenomenon that could boost optical data storage and communications -- is now working to capture all the colors of the rainbow.
In a paper published March 29 in the Proceedings of the National Academy of Sciences, Qiaoqiang Gan (pronounced "Chow-Chung" and "Gone"), PhD, an assistant professor of electrical engineering at the University at Buffalo's School of Engineering and Applied Sciences, and his colleagues at Lehigh University, where he was a graduate student, described how they slowed broadband light waves using a type of material called nanoplasmonic structures.
Gan explains that the ultimate goal is to achieve a breakthrough in optical communications called multiplexed, multiwavelength communications, where optical data can potentially be tamed at different wavelengths, thus greatly increasing processing and transmission capacity.
He notes that it is widely recognized that if light could ever be stopped entirely, new possibilities would open up for data storage.
"At the moment, processing data with optical signals is limited by how quickly the signal can be interpreted," he says. "If the signal can be slowed, more information could be processed without overloading the system."
Gan and his colleagues created nanoplasmonic structures by making nanoscale grooves in metallic surfaces at different depths, which alters the materials' optical properties.
These plasmonic chips provide the critical connection between nanoelectronics and photonics, Gan explains, allowing these different types of devices to be integrated, a prerequisite for realizing the potential of optical computing, "lab-on-a-chip" biosensors and more efficient, thin-film photovoltaic materials.
According to Gan, the optical properties of the nanoplasmonic structures allow different wavelengths of light to be trapped at different positions in the structure, potentially allowing for optical data storage and enhanced nonlinear optics.
The structures Gan developed slow light down so much that they are able to trap multiple wavelengths of light on a single chip, whereas conventional methods can only trap a single wavelength in a narrow band.
"Light is usually very fast, but the structures I created can slow broadband light significantly," says Gan. "It's as though I can hold the light in my hand."
That, Gan explains, is because of the structures' engineered surface "plasmon resonances," where light excites the waves of electrons that oscillate back and forth on metal surfaces.
In this case, he says, light can be slowed down and trapped in the vicinity of resonances in this novel, dispersive structural material.
Gan and his colleagues also found that because the nanoplasmonic structures they developed can trap very slow resonances of light, they can do so at room temperature, instead of at the ultracold temperatures that are required in conventional slow-light technologies.
"In the PNAS paper, we showed that we trapped red to green," explains Gan. "Now we are working on trapping a broader wavelength, from red to blue. We want to trap the entire rainbow."
Gan, who was hired at UB under the UB 2020 strategic strength in Integrated Nanostructured Systems, will be working toward that goal, using the ultrafast light source in UB's Department of Electrical Engineering in the laboratory of UB professor and vice president for research Alexander N. Cartwright.
"This ultrafast light source will allow us to measure experimentally just how slow is the light that we have trapped in our nanoplasmonic structures," Gan explains. "Once we know that, we will be able to demonstrate our capability to manipulate light through experiments and optimize the structure to slow the light further."
Co-authors with Gan on the study are Filbert Bertoli, Yongkang Gao, Yujie Ding, Kyle Wagner and Dmitri Vezenov, all of Lehigh University.
The University at Buffalo is a premier research-intensive public university, a flagship institution in the State University of New York system and its largest and most comprehensive campus. UB's more than 28,000 students pursue their academic interests through more than 300 undergraduate, graduate and professional degree programs. Founded in 1846, the University at Buffalo is a member of the Association of American Universities.
Ellen Goldbaum | EurekAlert!
Six-legged robots faster than nature-inspired gait
17.02.2017 | Ecole Polytechnique Fédérale de Lausanne
Did you know that IR heat plays a central role in the production of chocolates?
14.02.2017 | Heraeus Noblelight GmbH
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
17.02.2017 | Medical Engineering
17.02.2017 | Medical Engineering
17.02.2017 | Health and Medicine