Bragg-grating-enhanced narrowband spontaneous parametric downconversion
Li Yan, Lijun Ma, Xiao Tang · Optics Express · 2010
We propose a new method to narrow the line width of entangled photons generated from spontaneous parametric downconversion (SPDC). The single structure device incorporates an internal Bragg grating onto a nonlinear optical waveguide. We study theoretically the spectral characteristics of SPDC under two Bragg grating structures. We show that using the Bragg grating with a midway pi-phase shifter, it is a promising way to generate narrow-line (~GHz to sub-GHz) entangled photons.