Researchers at EEEL have developed an all-fiber photon-pair source with the highest coincidence-to-accidental ratio (CAR) ever reported in the fiber-optic telecommunications C-band. The key innovations were careful optimization of pair-production efficiency and detailed minimization of background photons, including cooling the nonlinear fiber to 4K to eliminate Raman scattering and reducing other noise sources through thorough system design. This resulted in a CAR of 1300 at a pair generation rate of 2 kHz, a factor of 12 higher than previously reported results in the C-band.
The researchers also demonstrated that using a continuous-wave laser instead of a conventional pulsed laser could achieve a photon pair generation rate as high as 40 MHz, comparable to the brightest fiber-based and free-space crystal photon pair sources available. This all-fiber source generating photon pairs in the important fiber-optic telecommunications C-band is essential for long-distance distribution of quantum information and has broad applications in quantum communications and quantum computing.
Keywords: 1. photon-pair, 2. fiber-optic, 3. telecommunications, 4. Raman scattering, 5. quantum information
