Scientists Create Electrically-Pumped Nanolaser Capable Of Performing At Room Temperature
14 March 2013
Scientists at Arizona State University have created an electrically powered nanoscale laser that can perform reliably at room temperature, paving the way for the use of such devices in a range of practical applications, Laser Focus World magazine has reported.
The nanolaser could be used as a building block in active metamaterials, which compensate for optical loss by emitting light in phase with that traveling in the metamaterial.
The research team was led by Cun-Zheng Ning who has been trying for years to create a workable nanolaser with a volume smaller than its wavelength cubed - an intermediate step toward further miniaturization of lasers.
First, the team developed the thinnest nanolaser that can perform at low temperatures and two years ago the researchers were able to increase the operating temperature to 260 K. Most recently, the team showed a device that could operate at room temperature. Though the device operation was not perfect because of overheating, the most recent achievement is an eightfold improvement over previous results from a year ago, finally providing a clear demonstration of continuous electrically-powered operation of a laser at room temperature, Ning said.
"In terms of fundamental science, it shows for the first time that metal heating loss is not an insurmountable barrier for room-temperature operation of a metallic cavity nanolaser under electrical injection. For a long time, many doubted if such operation is even possible at all," Ning stated.
Yet many challenges remain, Ning says, such as the ability to integrate nanolasers into a photonic on-chip platform, as well as to prolong the lifetime of laser operation and to further expand the capabilities of such devices. Scientists are also yet to fully understand the physical mechanisms involved in the interaction of photons with metallic structures on small scale.