Quantum efficiency measurement of single-photon detectors using photon pairs generated in optical fibers

Abstract

Using the correlated signal and idler photon pairs generated in a dispersion shifted fiber by a pulsed pump, we measure the quantum efficiency of a InGaAs/InP avalanche photodiode-based single photon detector. Since the collection efficiency of photon pairs is a key parameter to correctly deduce the quantum efficiency, we carefully characterize the collection efficiency by studying correlation dependence of photon pairs upon the spectra of pump, signal and idler photons. This study allows us to obtain quantum efficiency of the single photon detector by using photon pairs with various kinds of bandwidths.

Characterization of a fiber-based source of heralded single photons

“…is the collection efficiency of the photon pairs for the heralding photons detected in idler channel [26], and 0 in the bracket stands for t 0k − t 0l = 0. Equation (22) indicates the coincidence of signal and idler photons produced by the same pump pulse is the sum of the accidental coincidence and the true coincidences come from the pair events.…”

“…1). If the conditional detection efficiency η D is simply defined as the ratio between true coincidence and the trigger photon detection rate, i.e., Equation (29) shows the heralding efficiency H is equivalent to the collection efficiency of the photon pairs for the heralding trigger photons detected in idler channel [26]. Figure 4 plots H as a function of the bandwidth of signal and idler photons.…”

“…The corresponding value of g (2) c (0) can be obtained according to Eq. (26). To figure out the dependence of g (2) c (0) on the brightness in different cases, we extract the normalized detection rate of photon pairs, P pair , from the measured single counts and twofold coincidences and sketch g (2) c (0) as a function of P pair .…”

Generation of photon pairs in dispersion shift fibers through spontaneous four wave mixing: Influence of self-phase modulation

“…Our investigations is not only helpful for developing an all fiber source of photon pairs with low background noise, but also useful for exploring its applications [17,18].…”

“…This arrangement is equivalent to a polarization interferometer formed between PBS 3 and PBS 2 . The linearly polarized pump with a Gaussian shaped spectrum is obtained by using a filter to spectrally carve the output of a mode-locked femto-second fiber laser having a repetition rate of about 41 MHz [18], and the time bandwidth product of pump is about 0.6. M 2 is mounted on a piezoelectric-transducer (PZT)-driven translation stage, which allows precise adjustment of the relative delay and phase difference between P H and P V .…”