  Efficient generation and detection of indistinguishable twin photons are at
the core of quantum information and communications technology (Q-ICT). These
photons are conventionally generated by spontaneous parametric down conversion
(SPDC), which is a probabilistic process, and hence occurs at a limited rate,
which restricts wider applications of Q-ICT. To increase the rate, one had to
excite SPDC by higher pump power, while it inevitably produced more unwanted
multi-photon components, harmfully degrading quantum interference
visibility.Here we solve this problem by using recently developed 10 GHz
repetition-rate-tunable comb laser, combined with a group-velocity-matched
nonlinear crystal, and superconducting nanowire single photon detectors. They
operate at telecom wavelengths more efficiently with less noises than
conventional schemes, those typically operate at visible and near infrared
wavelengths generated by a 76 MHz Ti Sapphire laser and detected by Si
detectors. We could show high interference visibilities, which are free from
the pump-power induced degradation. Our laser, nonlinear crystal, and detectors
constitute a powerful tool box, which will pave a way to implementing quantum
photonics circuits with variety of good and low-cost telecom components, and
will eventually realize scalable Q-ICT in optical infra-structures.
