Generation of photons with all-optically reconfigurable entanglement in integrated nonlinear waveguides

TL;DR

This paper proposes a method to generate reconfigurable entangled photon pairs in integrated nonlinear waveguides by controlling classical pump inputs and domain poling, enabling tailored quantum states for quantum information applications.

Contribution

It introduces a novel all-optical reconfiguration technique for generating specific entangled photon states using domain poling and pump phase control in integrated waveguides.

Findings

Reconfigurable generation of Bell states demonstrated.

Control over biphoton quantum interference achieved.

Device design allows for tailored entanglement states.

Abstract

We predict that all-optically reconfigurable generation of photon pairs with tailored spatial entanglement can be realized via spontaneous parametric down-conversion in integrated nonlinear coupled waveguides. The required elements of the output quantum wavefunction are directly mapped from the amplitudes and phases of the classical laser pump inputs in each waveguide. This is achieved through special nonuniform domain poling, which locally inverts the sign of quadratic nonlinear susceptibility and accordingly shapes the interference of biphoton quantum states generated along the waveguides. We demonstrate a device configuration for the generation of any linear combination of two-photon Bell states.