Application of a Tunable Fiber Optic Source of Biphotons to Determine the Spectral Dependence of the Second-Order Cross-Correlation Function

Quantum-entangled two-photon fields (biphotons) are attracting increasing interest in practical applications based on high photon correlation. Using a tunable fiber optic biphoton source, it was demonstrated that the performance of a quantum optical system at various wavelengths can be evaluated by correlation measurements. It was established that the results of such measurements, particularly those related to the efficiency of the detectors used, depend significantly on the optical losses in the system.