The Inter-University Centre for Astronomy and Astrophysics (IUCAA) has developed an indigenous technology called PhotonSync, which can convert ordinary telecom optical fibres into ultra-stable quantum communication channels.
One of the key challenges in building quantum networks is that conventional optical fibres are affected by temperature variations, vibrations, seismic activity and other environmental factors. These disturbances introduce noise in photons travelling through the fibres, making accurate transmission of quantum information difficult. PhotonSync addresses this by creating a phase coherent fibre (PCF) link and actively stabilising the phase and frequency of light travelling through optical fibres, enabling photons to retain their precise properties over long distances.
With PhotonSync, quantum data transfer using photons becomes significantly more accurate. Compared to normal fibres, the PCF link can achieve up to a 47.5 dB reduction in phase noise.
In addition, PhotonSync has been granted a trademark. The system has been successfully tested on field-deployed optical fibres up to 3.3 km, and on fibre spools up to 71 km. Researchers from Jaypee Institute of Information Technology (JIIT), in a separate study, found that PhotonSync can reduce the quantum bit error rate by nearly 73 times compared to unstabilised fibres, improving the feasibility of long-distance secure quantum communication.