Storage of up-converted telecom photons in a doped crystal

Abstract

We report on an experiment that demonstrates the frequency up-conversion of telecommunication wavelength single-photon-level pulses to be resonant with a ${\mathrm{Pr}}^{3+}$:${\mathrm{Y}}_2\mathrm{Si}{\mathrm{O}}_5$ crystal. We convert the telecom photons at $1570\mathrm{nm}$ to $606\mathrm{nm}$ using a periodically-poled potassium titanyl phosphate nonlinear waveguide. The maximum device efficiency (which includes all optical loss) is inferred to be ${\eta }_{\mathrm{dev}}^{\max }=22\pm 1$ (internal efficiency ${\eta }_{\mathrm{int}}=75\pm 8$) with a signal to noise ratio exceeding 1 for single-photon-level pulses with durations of up to 560ns. The converted light is then stored in the crystal using the atomic frequency comb scheme with storage and retrieval efficiencies exceeding ${\eta }_{\mathrm{AFC}}=20$ for predetermined storage times of up to $5\mu \mathrm{s}$. The retrieved light is time delayed from the noisy conversion process allowing us to measure a signal to noise ratio exceeding 100 with telecom single-photon-level inputs. These results represent the first demonstration of single-photon-level optical storage interfaced with frequency up-conversion.

References in corpus (6)

• Quantum storage of entangled telecom-wavelength photons in an erbium-doped optical fibre
• Efficient and long-lived quantum memory with cold atoms inside a ring cavity
• Long-Distance Entanglement Distribution with Single-Photon Sources
• Two-photon interference using background-free quantum frequency conversion of single photons from a semiconductor quantum dot
• Approaches for a quantum memory at telecommunication wavelengths
• Storage and retrieval of a light in telecomband in a cold atomic ensemble