Correlated photon pair generation in silicon wire waveguides

In this paper, correlated photon pairs at 1.55μm are generated in a silicon wire waveguidewith a length of 1.6 mm. The ratio between coincidence count rate and accidental coincidence count rate under room temperature is 19, showing the property of low Raman noise and strong quantum correlation. Moreover, the experiment shows that photon pair generation isstrongly dependent on pump polarization direction. Using quantum perturbation theory, we analyze the contribution of scalar and vectorspontaneous four-wave mixing processes to the generated photon pairs. Due tohigh nonlinear coefficient and high coupling efficiency, the generation rate in quasi-TE mode is much larger than that in quasi-TM mode.The combination of calculated photon pair generation rates through scalar and vector spontaneous four-wave mixing processes agrees well with the experimental result.