Noise-free quantum optical frequency shifting driven by mechanics

TL;DR

This paper demonstrates a noise-free, high-efficiency method for shifting the frequency of single photons using mechanical waveguide modulation, enhancing quantum communication capabilities.

Contribution

It introduces the first integrated, near-unity efficiency frequency manipulation of single photons via mechanical stretching and compressing of a waveguide at GHz rates.

Findings

Achieved frequency shifts up to 150 GHz at telecom wavelengths.

Demonstrated preservation of quantum coherence after frequency shifting.

Realized frequency manipulation without measurable added noise.

Abstract

The ability to manipulate single photons is of critical importance for fundamental quantum optics studies and practical implementations of quantum communications. While extraordinary progresses have been made in controlling spatial, temporal, spin and orbit angular momentum degrees of freedom, frequency-domain control of single photons so far relies on nonlinear optical effects, which have faced obstacles such as noise photons, narrow bandwidth and demanding optical filtering. Here we demonstrate the first integrated near-unity efficiency frequency manipulation of single photons, by stretching and compressing a waveguide at 8.3 billion cycles per second. Frequency shift up to 150 GHz at telecom wavelength is realized without measurable added noise and the preservation of quantum coherence is verified through quantum interference between twin photons of different colors. This single photon frequency control approach will be invaluable for increasing the channel capacity of quantum communications and compensating frequency mismatch between quantum systems, paving the road toward hybrid quantum network.