Application of entangled photons source in measurement of single-pho ton-detector’ s quantum efficiency

초록

An absolute measurement of single photon detector’ s quantum efficiency can be realized by using entangled photons generated in spontaneous parametric down-conversion (SPDC) effect of nonlinear crystal. Theory of this method is demonstrated. Using 351.1nm output of a tunable laser to pump BBO crystal, the measurement system of quantum efficiency of single photon detector based on entangled photons is performed. Quantum efficiency of photomultiplier at 702nm is measured as (5.96±0.003) %, related combined uncertainty of the results is about 2.61%. Comparing with traditional method, advantages of this method is independent to any other standard.