A newly developed quantum sensor that was created by researchers at the University of Waterloo's Institute for Quantum Computing has proven that it can perform better than all the current technologies that are used in monitoring the success of cancer treatments.

The quantum sensors are the first of their kind, and they are based on semiconductor nanowires that can monitor and detect single particles of light by using high timing resolution, efficiency, and speed over a wavelength range that is unparalleled, from near-infrared to ultraviolet.

The sensor can also improve quantum communication and remote sensing capabilities significantly.

"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," said principal investigator Michael 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."

The quantum sensor that is designed in Reimer's lab is efficient and fast that it can detect even a single particle of light, that is known as a photon, and it can refresh for the next one within nanoseconds. The researchers created a series of tapered nanowires that can make incoming photons into electric current that can be detected and amplified.

High-speed imaging from space, remote sensing, getting long-range, high-resolution 3D images, quantum communication and oxygen detection for monitoring cancer treatment are all part of an application that could benefit from the strong, single photon detection that this quantum sensor can provide.

The series of semiconducting nanowire gets its high speed, efficiency, and timing resolution because of the quality of its materials, its profile, the number of nanowires and the optimization of the nanowire arrangement and shape. The quantum sensor can detect a spectrum of light with high timing resolution and high efficiency while operating at room temperature. Reimer said that the absorption of the range could be widened even further by using different materials.

"This device uses Indium Phosphide nanowires. Changing the material to Indium Gallium Arsenide, for example, can extend the bandwidth even further towards telecommunications wavelengths while maintaining performance," Reimer said. "It's state of the art now, with the potential for further enhancements."

Once the quantum sensor is set with the right electronics and portable cooling, it 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.