Quantum optical waveform conversion.

Proposals for long-distance quantum communication rely on the entanglement of matter-based quantum nodes through optical communications channels, but the entangling light pulses have poor temporal behavior in current experiments. Here we show that nonlinear mixing of a quantum light pulse with a spectrally tailored classical field can compress the quantum pulse by more than a factor of 100 and flexibly reshape its temporal waveform while preserving all quantum properties, including entanglement. Our scheme paves the way for quantum communication at the full data rate of optical telecommunications.