Quantum photon pair generation in hollow-core photonic crystal fibers: a simulation-based study

We present a comprehensive numerical investigation of entangled photon pair generation via spontaneous four-wave mixing (SFWM) in hollow-core photonic crystal fibers (HC-PCFs). By analyzing various fiber geometries, dispersion profiles, and anti-resonant characteristics, we identify optimal configurations that enhance photon-pair generation efficiency. Our study highlights the crucial roles of group velocity dispersion engineering, pump parameters, and phase-matching conditions in shaping the joint spectral amplitude (JSA) of the emitted photons. Utilizing gas-filled or evacuated HC-PCFs significantly reduces Raman noise by minimizing field overlap with the glass, while maintaining strong nonlinear interactions. The results reveal practical regimes for improving spectral purity and heralding efficiency. These findings provide practical design guidelines for scalable, low-noise quantum light sources suitable for quantum communication technologies. We bridge fiber design and nonlinear optics to create a predictive model and practical design charts for application-specific quantum light sources.