Video for the general public released by Natalia Korolkova's EU project PhoG

1 June 2020

In connection with the outreach activities in the framework of the EU Flagship Quantum Technologies project PhoG (Coordinator: Professor Natalia Korolkova) a video for the general public has been produced and is available in English and in Russian.  


Project PhoG (Sub-Poissonian Photon Gun by Coherent Diffusive Photonics) develops a family of unique devices for generation of quantum states of light, a tailored light with user-selected properties. PhoG devices are based on engineered nonlinear loss in dissipatively-coupled optical waveguide networks, with the "cheap" attenuated coherent states as input. The nonlinear loss acts over much faster timescales than conventional (linear) loss, and so the system is robust to realistic physical limitations. In different regimes, PhoG acts either as a deterministic source of highly sub-Poissonian light, or as a source of entangled photons in different state configurations. Such wide performance range is enabled by a unique physical mechanism behind PhoG and by unique capabilities of the ultrafast laser inscription techniques. The strength of this approach is the ability to inscribe arbitrary patterns of 3-dimensional waveguide structures to create a desired configuration. The devices are compact, on a glass chip. Modern technologies widely use such integrated platforms which renders PhoG highly compatible with current technological systems.

Such quantum sources PhoGs (Photon Guns) will enhance the performance of many protocols across the Quantum Technologies arena by providing a ready alternative to attenuated quantum coherent states which are normally used because of their convenience. Within the project, we implement these devices to enhance super-resolution imaging and to improve stability of the commercial atomic clock. We will create proof-of-principle demonstrations of these applications. For the characterisation purposes, we have developed a unique detector, that can resolve large photon numbers and is based on the established concept of time-multiplexing, which was pioneered by members of the consortium.

The test board and the algorithms have been developed for the application of PhoG in super-resolution microscopy. Laser light passing through a quantum network of PhoG is transformed into special, entangled states of light. This allows to highly enhance the image quality using spatiotemporal quantum correlations. Apart from the purely quantum realm, our coherent devices can have classical applications, be used in quantum-inspired technologies, which perform better than standard classical devices. They will enrich integrated quantum photonics with devices in unusual operational regimes and can be generalised to other photonic integrated circuits (PIC) platforms.

In terms of societal applications beyond quantum realm, PhoG will contribute to the development of complex, custom designed 3 dimensional waveguide components that can be quickly changed and prototyped. It will advance on a new level the use of mid-infrared transmissive, high refractive index non-linear materials.
This is particular important for biological applications, as mid-infrared sources and detectors allow access to the "fingerprint" region where compounds and molecules have distinct spectra allowing them to be identified. Custom light guiding components, spectrographs and lens arrays for the mid-infrared can be developed for minimally invasive portable detectors for precise and rapid clinical diagnosis and identification of diseases.
For astronomical applications, integrated high precision, low loss spectrographs for the mid-infrared can be produced, which when used with ground- based telescopes operating with adaptive optics have the potential to identify and characterise Earth-like planets with the possibility to search for those capable of supporting life. Though not explicitly within the scope of the PhoG project, these PhoG-related advances of techniques and the expertise of partners contributes to further progress in all these applications.