Mar 5 2019
Scientists from the Institute for Quantum Computing (IQC) of the University of Waterloo have developed a novel quantum sensor that has been shown to outpace the current generation of technologies and could lead to considerable developments in tracking the success of cancer treatments and long-range 3D imaging.
Artist’s rendering of the interaction of single incident photon pulses and a tapered semiconductor nanowire array photo-detector. (Image credit: University of Waterloo)
Based on semiconductor nanowires, the new quantum sensors are the first of their kind and are capable of detecting single particles of light, or photons, with excellent timing speed, resolution, and efficiency over an unmatched wavelength range, from near-infrared to ultraviolet. In addition, the innovative technology has the potential to considerably enhance remote sensing capabilities and quantum communication.
A sensor needs to be very efficient at detecting light. In applications like quantum radar, surveillance, and nighttime operation, very few particles of light return to the device. In these cases, you want to be able to detect every single photon coming in.
Michael Reimer, Assistant Professor, Department of Electrical and Computer Engineering, Faculty of Engineering, University of Waterloo
Reimer is the principal investigator of the study and also an IQC faculty member.
Designed in Reimer’s laboratory, the sophisticated quantum sensor is so quick and efficient that it can easily absorb and spot a single photon, and can refresh for the subsequent one within nanoseconds. The team developed a range of tapered nanowires that is capable of converting incoming photons into electric current, which can then be amplified and identified.
Quantum communication, high-speed imaging from space, remote sensing, attaining high-resolution, long-range 3D images, and singlet oxygen detection for dose monitoring in cancer treatment are all different types of applications that can possibly gain from the kind of powerful single photon detection afforded by the novel quantum sensor.
The semiconducting nanowire array is able to attain its efficiency, high speed, and timing resolution because of the doping profile, the number of nanowires, the quality of its materials, and the optimization of the arrangement and shape of nanowires.
A broad spectrum of light is detected by the quantum sensor with high timing resolution and high efficiency, all the while working at room temperature. The absorption of the spectrum can be broadened even more with the help of different materials, emphasized Reimer.
This device uses Indium Phosphide (InP) nanowires. Changing the material to Indium Gallium Arsenide (InGaAs), for example, can extend the bandwidth even further towards telecommunications wavelengths while maintaining performance. It’s state of the art now, with the potential for further enhancements.
Michael Reimer, Assistant Professor, Department of Electrical and Computer Engineering, Faculty of Engineering, University of Waterloo
As soon as the prototype is packaged using portable cooling and the right electronics, the quantum sensor is ready for testing beyond the laboratory setting.
“A broad range of industries and research fields will benefit from a quantum sensor with these capabilities,” Reimer said.
In association with scientists at the Eindhoven University of Technology, “Tapered InP nanowire arrays for efficient broadband high-speed single photon detection” was published in Nature Nanotechnology on March 4th, 2019.
The study was partly funded by the Canada First Research Excellence Fund (CFREF).