Quantum theory and applications of fiber-based parametric devices

Parametric devices based on four-wave mixing processes in fibers can amplify, frequency convert, phase conjugate, regenerate, sample and delay signals in conventional communication systems. They can also generate and frequency-convert photons used in quantum-information experiments. Photons can be frequency-converted by Bragg scattering in a fiber, which is the analog of sum-frequency generation in a crystal.