A new nanolaser changes colors using the same mechanism that chameleons use.
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.
“Chameleons can easily change their colors by controlling the spacing among the nanocrystals on their skin, which determines the color we observe,” says Teri W. Odom, professor of chemistry at Northwestern University. “This coloring based on surface structure is chemically stable and robust.”
The same way a chameleon controls the spacing of nanocrystals on its skin, the 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,” says Odom, co-corresponding author of the paper in Nano Letters with chemistry professor George C. Schatz.
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.
The National Science Foundation and the Vannevar Bush Faculty Fellowship from the US Department of Defense supported the work.
Source: Northwestern University