Narrow-Band Photon Pairs Generated from Spontaneous Parametric Down Conversion in a Bragg-Grating Enhanced Waveguide

摘要

We propose a new method to narrow the linewidth of photon pairs generated from spontaneous parametric down conversion (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 n-phase shifter is a promising way to implement narrow-line (~GHz to sub-GHz) entangled photon sources.