Efficient generation of twin photons at telecom wavelengths with 10 GHz repetition-rate tunable comb laser

TL;DR

This paper presents a method for generating twin photons at telecom wavelengths using a 10 GHz tunable comb laser, enhancing efficiency and reducing noise, thereby advancing scalable quantum information and communication technologies.

Contribution

The authors demonstrate a novel combination of a 10 GHz tunable comb laser, group-velocity-matched nonlinear crystal, and superconducting detectors for efficient, low-noise twin photon generation at telecom wavelengths.

Findings

High interference visibility achieved without pump-power degradation

Efficient photon generation at telecom wavelengths with reduced noise

Potential for scalable quantum photonics circuits

Abstract

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.