Narrow- and broadband single-photon sources using customised-tapered waveguides
Abstract
Presented here are the findings of a recent thorough investigation into
spontaneous parametric four-wave mixing processes in third-order nonlinear waveguides with continuous tapering patterns. It has been previously
shown that these tapered devices can be exploited to quasi-phase-match
the four-wave mixing process and enhance its conversion efficiency by several orders of magnitude. I start with validating the developed quantum
model by reproducing the existing results in the literature. Furthermore,
through selection of different tapering profiles, I show that these devices
can serve as efficient sources of heralded single-photons, with either narrow
or broadband spectral widths and at on-demand frequencies. Simultaneously, I was able to use the aforementioned model to determine the fibre
length at which the spectral purity, an important property for quantum
information applications, is maximised.