In the first part of the project, we developed the commercial free-space single photon chip. This chip is operated through free-space optical lenses. To use the chip, the customer needs an optical lab with optical tables, free space optics, a pulsed tunable laser, and a cryostat with optical lenses. The chip has been tested, and our customers confirmed that the chip has market-leading specs. The chip has been sold and installed in several European labs.
In the second part of the project, we developed in-house capabilities for gluing an optical fiber to the chip. This greatly simplifies the operation of the device. During the project, the gluing procedure was refined and optimized to give reproducible high-quality fiber couplings. We have also implemented new protocols for the excitation and collection of the photons which increase the specs of the system.
The last part of the project was to integrate the fiber-coupled chip into a full plug-and-play rack-mounted system. For the system, we used a commercial cryostat from Attocube designed for the integration of fiber-coupled products, and a commercial laser, while the other parts, including an optical module for excitation and output filtering, were developed internally. The full system was successfully delivered to Orca computing and will be part of a quantum computing system delivered for the UK testbed in 2025.
The single-photon source emits photons at 950nm. This wavelength is incompatible with the telecom infrastructure. We have therefore in parallel working on a product emitting at 1310nm, the telecom o-band. During the project we have developed the recipes for growing quantum dots that emit at this wavelength and an O-band single photon source product is expected to be launched in 2025.
