Quantum Theory of Distributed-Feedback Parametric Amplifiers and Oscillators

Optical parametric amplifiers and oscillators are among the best-developed quantum light sources, having already been adopted in precision measurement and underpinning various quantum computing and communication paradigms. Meanwhile, progress in photonic structures such as Bragg gratings has enabled distributed feedback oscillators to become widely established as classical laser sources with desirable properties. Recent work in fabricating and processing photonic structures in nonlinear media opens the path to combining these two programs to realize distributed feedback parametric oscillators. Such devices have great potential as sources of quantum light, especially for squeezed vacuum, a crucial resource state in emerging quantum technologies. In this study, an analytic and fully quantum-mechanical model of the dynamics of such devices is presented. This approach gives explicit results for the key properties of these sources, including the parametric oscillation pump threshold, intracavity mode, tunability, and quantum statistics of the output modes. These results underpin future work on a versatile class of next-generation quantum light source.