Cancer treatment monitoring quantum sensor is anything but nano
Thursday, May 9, 2019
A quantum sensor newly developed by researchers at the University of Waterloo’s Institute for Quantum Computing (IQC) is capable of detecting and absorbing single particles of light, making a giant leap into the advancement of long-range 3D imaging and in monitoring the success of cancer treatments.
Figure 1. Artist’s rendering of the interaction of single incident photon pulses and a tapered semiconductor nanowire array photodetector.
The sensor is based on semiconductor nanowires that can detect single particles of light with high-timing resolution, speed and efficiency over a wavelength range from ultraviolet to near-infrared. It also has applications in remote sensing, high-speed imaging from space, acquiring long-range high-resolution 3D images, quantum communication, and singlet oxygen detection for dose monitoring in cancer treatment.
The next generation quantum sensor, designed in the lab of principal investigator Michael Reimer, is so fast and efficient that it can absorb and detect a single photon, and refresh for the next one within nanoseconds. The researchers created an array of tapered nanowires that turn incoming photons into electric current, which is amplified and detected. “A sensor needs to be very efficient at detecting light. In applications like quantum radar, surveillance, and night time operation, very few particles of light return to the device,” said Reimer, an IQC faculty member and assistant professor in the Faculty of Engineering’s electrical and computer engineering department. “In these cases, you want to be able to detect every single photon coming in.”
Michael Reimer
The sensor detects a broad spectrum of light with high efficiency and high timing resolution, all while operating at room temperature. Reimer added that the spectrum absorption can be broadened even further with different materials. “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.” stated Reimer.
Once the prototype is packaged with the right electronics and portable cooling, the sensor is ready for testing beyond the lab. “A broad range of industries and research fields will benefit from a quantum sensor with these capabilities,” said Reimer.
The new sensor which was developed in collaboration with researchers at the Eindhoven University of Technology, is chronicled in a paper titled Tapered InP nanowire arrays for efficient broadband high-speed single photon detection, which was published in Nature Nanotechnology on March 4. This research was undertaken thanks in part to funding from the Canada First Research Excellence Fund (CFREF).