Controllable Frequency Entanglement via Auto-Phase-Matched Spontaneous Parametric Down-Conversion

Abstract

A new method for generating entangled photons with controllable frequency correlation via spontaneous parametric down-conversion (SPDC) is presented. The method entails initiating counter-propagating SPDC in a single-mode nonlinear waveguide by pumping with a pulsed beam perpendicular to the waveguide. The method offers several advantages over other schemes, including the ability to generate frequency-correlated photon pairs regardless of the dispersion characteristics of the system. Numerical evidence demonstrates the improvement provided by this source in the special case of frequency-correlated two-photon states.

5 pages, 4 figures; recalculated the bold visibility curve in Fig. 4 for a GaAs (instead of KTP) waveguide--conclusions unchanged; accepted for publication in Physical Review A