Quantum Flagship’s S2QUIP Reports Optical Switch Compatible with Heat-Sensitive Single-Photon Detectors–Potential Boost for Quantum Technology

(NewElectronics) The European Quantum Flagship project S2QUIP  is reported to have developed an optical switch that is reconfigured with microscopic mechanical movement rather than heat, making the switch compatible with heat-sensitive single-photon detectors.
Currently, optical switches work by locally heating light guides inside a semiconductor chip. “This approach does not work for quantum optics,” said Samuel Gyger, a researcher from the KTH Royal Institute of Technology in Stockholm.
“Because we want to detect every single photon, we use quantum detectors that work by measuring the heat a single photon generates when absorbed by a superconducting material. If we use traditional switches, our detectors will be flooded by heat, and wont work at all.”
The new method enables control of single photons without the disadvantage of heating up a semiconductor chip and rendering single-photon detectors useless.
By using MEMS actuation it is possible to enable optical switching and photon detection on a single semiconductor chip while maintaining the cold temperatures required by single-photon detectors.
“Our technology will help to connect all building blocks required for integrated optical circuits for quantum technologies,” said Errando Herranz, who led the work at KTH.