Near-zero anomalous dispersion Ge11.5As24Se64.5 glass nanowires for correlated photon pair generation: Design and analysis

We show that highly nonlinear chalcogenide glass nanowire waveguides with near-zero anomalous dispersion should be capable of generating correlated photon-pairs by spontaneous four-wave mixing at frequencies detuned by over 17 THz from the pump where Raman noise is absent. In this region we predict a photon pair correlation of >100, a figure of merit >10 and brightness of ̃8×10⁸ pairs/s over a bandwidth of >15 THz in nanowires with group velocity dispersion of <5 ps·km^-1nm ^-1. We present designs for double-clad Ge^11.5As ²⁴Se^64.5 glass nanowires with realistic tolerance to fabrication errors that achieve near-zero anomalous dispersion at a 1420 nm pump wavelength. This structure has a fabrication tolerance of 80-170 nm in the waveguide width and utilizes a SiO₂/Al₂O₃ layer deposited by atomic layer deposition to compensate the fabrication errors in the film thickness.