Tag Archives: nanolaser

Colo(u)r-changing nanolaser inspired by chameleons

Caption: Novel nanolaser leverages the same color-changing mechanism that a chameleon uses to camouflage its skin. Credit: Egor Kamelev Courtesy: Northwestern University

I wish there was some detail included about how those colo(u)rs were achieved in that photograph. Strangely, Northwestern University (Chicago, Illinois, US) is more interested in describing the technology that chameleons have inspired. A June 20, 2018 news item on ScienceDaily announces the research,

As a chameleon shifts its color from turquoise to pink to orange to green, nature’s design principles are at play. Complex nano-mechanics are quietly and effortlessly working to camouflage the lizard’s skin to match its environment.

Inspired by nature, a Northwestern University team has developed a novel nanolaser that changes colors using the same mechanism as chameleons. The work could open the door for advances in flexible optical displays in smartphones and televisions, wearable photonic devices and ultra-sensitive sensors that measure strain.

A June 20, 2018 Northwestern University news release (also on EurekAlert) by Amanda Morris, which originated the news item, expands on the theme,

“Chameleons can easily change their colors by controlling the spacing among the nanocrystals on their skin, which determines the color we observe,” said Teri W. Odom, Charles E. and Emma H. Morrison Professor of Chemistry in Northwestern’s Weinberg College of Arts and Sciences. “This coloring based on surface structure is chemically stable and robust.”

The research was published online yesterday [June 19, 2018] in the journal Nano Letters. Odom, who is the associate director of Northwestern’s International Institute of Nanotechnology, and George C. Schatz, Charles E. and Emma H. Morrison Professor of Chemistry in Weinberg, served as the paper’s co-corresponding authors.

The same way a chameleon controls the spacing of nanocrystals on its skin, the Northwestern team’s laser exploits periodic arrays of metal nanoparticles on a stretchable, polymer matrix. As the matrix either stretches to pull the nanoparticles farther apart or contracts to push them closer together, the wavelength emitted from the laser changes wavelength, which also changes its color.

“Hence, by stretching and releasing the elastomer substrate, we could select the emission color at will,” Odom said.

The resulting laser is robust, tunable, reversible and has a high sensitivity to strain. These properties are critical for applications in responsive optical displays, on-chip photonic circuits and multiplexed optical communication.

Here’s a link to and a citation for the paper,

Stretchable Nanolasing from Hybrid Quadrupole Plasmons by Danqing Wang, Marc R. Bourgeois, Won-Kyu Lee, Ran Li, Dhara Trivedi, Michael P. Knudson, Weijia Wang, George C. Schatz, and Teri W. Odom. Nano Lett., Article ASAP DOI: 10.1021/acs.nanolett.8b01774 Publication Date (Web): June 18, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

Move over laser—the graphene/carbon nanotube spaser is here, on your t-shirt

This research graphene/carbon nanotube research comes from Australia according to an April 16, 2014 news item on Nanowerk,

A team of researchers from Monash University’s [Australia] Department of Electrical and Computer Systems Engineering (ECSE) has modelled the world’s first spaser …

An April 16, 2014 Monash University news release, which originated the new item, describes the spaser and its relationship to lasers,,

A new version of “spaser” technology being investigated could mean that mobile phones become so small, efficient, and flexible they could be printed on clothing.

A spaser is effectively a nanoscale laser or nanolaser. It emits a beam of light through the vibration of free electrons, rather than the space-consuming electromagnetic wave emission process of a traditional laser.

The news release also provides more details about the graphene/carbon nanotube spaser research and the possibility of turning t-shirts into telephones,

PhD student and lead researcher Chanaka Rupasinghe said the modelled spaser design using carbon would offer many advantages.

“Other spasers designed to date are made of gold or silver nanoparticles and semiconductor quantum dots while our device would be comprised of a graphene resonator and a carbon nanotube gain element,” Chanaka said.

“The use of carbon means our spaser would be more robust and flexible, would operate at high temperatures, and be eco-friendly.

“Because of these properties, there is the possibility that in the future an extremely thin mobile phone could be printed on clothing.”

Spaser-based devices can be used as an alternative to current transistor-based devices such as microprocessors, memory, and displays to overcome current miniaturising and bandwidth limitations.

The researchers chose to develop the spaser using graphene and carbon nanotubes. They are more than a hundred times stronger than steel and can conduct heat and electricity much better than copper. They can also withstand high temperatures.

Their research showed for the first time that graphene and carbon nanotubes can interact and transfer energy to each other through light. These optical interactions are very fast and energy-efficient, and so are suitable for applications such as computer chips.

“Graphene and carbon nanotubes can be used in applications where you need strong, lightweight, conducting, and thermally stable materials due to their outstanding mechanical, electrical and optical properties. They have been tested as nanoscale antennas, electric conductors and waveguides,” Chanaka said.

Chanaka said a spaser generated high-intensity electric fields concentrated into a nanoscale space. These are much stronger than those generated by illuminating metal nanoparticles by a laser in applications such as cancer therapy.

“Scientists have already found ways to guide nanoparticles close to cancer cells. We can move graphene and carbon nanotubes following those techniques and use the high concentrate fields generated through the spasing phenomena to destroy individual cancer cells without harming the healthy cells in the body,” Chanaka said

Here’s a link to and a citation for the paper,

Spaser Made of Graphene and Carbon Nanotubes by Chanaka Rupasinghe, Ivan D. Rukhlenko, and Malin Premaratne. ACS Nano, 2014, 8 (3), pp 2431–2438. DOI: 10.1021/nn406015d Publication Date (Web): February 23, 2014
Copyright © 2014 American Chemical Society

This paper is behind a paywall.