FBGs in PCF for Four-Wave Mixing Sources for Quantum Optics

Photonic crystal fibers (PCFs) offer a high degree of design flexibility, particularly in terms of dispersion control, making them ideal for nonlinear optical processes. These fibers have found applications in various photonic fields, including fiber lasers [1] and single-photon generation [2]. Dispersion control allows for efficient four-wave mixing at desired wavelengths, which can be used in quantum optical sources. These processes require or are enhanced by the use of fiber Bragg gratings (FBGs) in the fiber. For example, in PCF-based FWM heralded single photon sources, FBGs can be used to filter out unwanted noise contributions, such as Raman noise. However, current filtering methods are lossy [3], making it desirable to integrate filters into the fibers themselves. Additionally, specially designed PCFs with FBGs can be used for in-fiber OPOs to generate squeezed light.